Category: 2, 7A, 7D, 8
Porcupines (Erethizon dorsatum)
This species is equipped to survive in extreme cold conditions, including tree-line habitats in far northern areas; however most species are tropical. These creatures have black to brownish-yellow fur and strong, short legs. They climb trees rather well due to the hairless soles on their feet. It has a round body, small ears, and head. The most recognizable feature of porcupines is their quills.
Adults bear over 30,000 large quills that cover the tops of their body and tail. Slenderer and longer quills cover their shoulders and sides. The majority of porcupine quills are found under long, white-tipped guard hairs and are not readily available until these animals are disturbed or in a warning posture. The guard hairs function to protect porcupines from rain and snow. They are also tactile in nature allowing these pests to feel the surrounding environment. These hairs are brown, or chestnut in coloration and six to10 inches in length giving porcupines a fluffy appearance.
Adult porcupine. Image courtesy of needsmore italiin @ English Wilipedia CC BY 3.0
Porcupines are well-adapted to climb in search of food. All four feet have long protruding claws that can easily penetrate or lodge in tree bark crevices. In addition, these claws are also used as grooming “combs” as they are elongated and easily extend through their long quills in order to reach the skin. They use their front feet to manipulate foods, such as small branches and fruit and to pull tree limbs to feeding range. Both sets of feet are equipped with footpads which are pebble-like in texture and are used to increase their ability to climb trunks of trees. Their backward pointing bristle-like quills located on the underside of the tail served to press against tree bark thus functioning as an anchor and minimize downward sliding.
An additional modification for climbing in males is the absence of an external male penis and a membrane that protects the female’s vagina. These make it difficult to distinguish males from females by superficial observation. Depending on the areas and season, the body weight of these animals can vary considerably. Male porcupines may average 13 to 25 pounds while females average 14 pounds. Their weight varies according to season due to the fact that porcupines store body fat at the beginning of winter and subsequently lose fat by spring. The average length of a mature adult is around 30 inches in length. Tail lengths, which are critical for defense from predators, range from 5¾ to 11¾ inches.
Porcupines are found throughout the Western U.S. and Canada. They are originally from South America, but as discussed above, have adapted and subsequently spread as far north as Alaska. They are found in lower deserts of California, deciduous forests, coniferous forests, and high desert regions of the Great Plains throughout the western states. Symptoms of the presence of porcupines include pellets or scats beneath feeding or resting trees and discarded “niptwigs” on the ground underneath trees. Niptwigs are terminal twigs that have been stripped of leaf blades. These twigs are in turn often eaten by deer and other mammals.
Porcupine dens are used for temporary shelter from rain, snow, and insects and minimizing the effects of winter. The two types of dens, pre-winter and winter are different in locations and structure. Pre-winter dens are normally found close to feeding or roosting sites and consist mainly of hollow trees. Winter dens are typically rock crevices in steep-sloped areas and are frequently located away from roosting sites. Extended freezing daytime temperatures stimulate these pests to enter a permanent den. In winter dens, porcupines commonly come out to feed at night. In the absence of rock crevices, these dens occur in live hollow trees, caves, branched crowns of evergreens and human buildings. Some animals remain outside in the winter, especially in locations where crevices and evergreens are not present.
Hemlock and Douglas fir are convenient food sources. These critters do not utilize bedding or nesting material in their dens, but instead prefer a clean dry floor. However, considerable quantities of feces can occur in the dens as they are used year after year. In certain locations (temperate, moist), the feces is broken down by mites; however, in arid, dryer climates, the feces will eventually form a hard concrete-like mass. As snow pack lessens and daytime temperature increase (less freezing days), porcupines emerge from winter dens.
Porcupines are nocturnal and typically active year-round spending much of their time resting in trees called “rest trees." Symptoms of the presence of an active den or resting tree are broken quills, fresh scats or feces, and the strong odor of their urine. Resting trees are an essential part of their habitat, even with adverse winter conditions. These trees are commonly conifers with thick crowns that provide cover and protection from predators.
During spring and early summer, these pests consume a variety of plants in order to “fatten up.” However, in deciduous forests, they don’t need ground vegetation to enhance their diet. Porcupines seem to be crazy about raspberry leaves and they will quickly consume this material whenever it is available.
Spring feeding on ground forage is dependent on the amount or presence of snow cover. If snow is lacking, porcupines feed exclusively on ground vegetation that is available and edible. Potential sources include flowers, grasses, flowering herbs, dandelions, and a variety other vegetation. Porcupines found in western Douglas fir-juniper forests consume ground vegetation in springtime but return to tree bark and evergreen needles come fall. Southwestern porcupines will consume shrubs such as chokeberry, plum, buckbrush, elder, raspberry canes, black haws, gooseberry, and buffalo berry. Herbaceous plants in their diets include cinquefoil, geranium, wyethia, lupine and lousewort. Porcupines need to gain weight rapidly in the spring and consequently feed on nitrogen-rich forage. Consumption of high nitrogen containing plants and changing climate subsequently triggers winter fur molting. The molting process is completed quickly (in a matter of days) leaving only the guard hairs, quills, and tail bristles. Unfortunately, the rich spring diet has a negative effect, namely a loss of sodium and subsequent desire for salt.
These animals regulate their feeding patterns relative to seasonal changes of available plant species. During summer, plants such as lupines, skunk cabbage, clover and other ground vegetation consists of up to 85 percent of their diet. The remaining consists of primarily twigs, inner tree bark, and leaves. The most common trees they prefer to feed on are aspen, cottowood, willow, and Ponderosa pine. These critters prefer feeding in trees with a smooth, thin, bark.
Come the fall months, these animals substantially increase their consumption of tree-based food to approximately 72 %. At this time ground vegetation becomes less common due to declining nutrient content and lower availability due to snow cover. In deciduous forests porcupines typically exhibit small home-ranges due to adequate food sources. On the other hand, in western mountainous regions they exhibit a considerable larger home range and must search considerably in order to meet their nutritional requirements.
During winter months, these creatures feed almost exclusively on trees including twigs, buds, tree bark, and evergreen needles. These pests have difficulty traveling through snow. As a consequence, winter activity and feeding activity can be reduced as much as ninety percent when compared to that in the spring and summer. It logically follows that their winter home-range is greatly reduced when compared to that of summer and spring.
Porcupines seek salt and find it in plants, road salt, salt-enriched soils, wood, and various other sources. Reportedly, these pests occasionally eat mud in salty-soil areas and consume various plants, such as aquatic liverwort and yellow water lily, both of which have a high salt content. Of course, rock salt, left over from salting winter roads are other sources of this essential mineral. Fresh animal bones, plywood, human-handled wood posts, timbers, old shoes and boots, paint, and the outer bark all contain salt. Any object impregnated with urine also attracts porcupines because of the salt content.
Prior to fighting, porcupines will warn others by displaying their quills, producing offensive odors, teeth chattering, and producing, threatening sounds. Porcupines use their quills as an ultimate form of defense. Porcupines shiver their bodies and simultaneously chatter their jaws, resulting in teeth to vibrate against one another. If all of warnings are ignored, porcupines use their quills when attacked. Quill tips have tiny fish-hook-like barbs that make removal difficult. The upper tail surface is equipped with short black quills that are considerably more dangerous than the longer back and neck quills. However, these pests cannot shoot or throw their quills. If a potential predator approaches, the porcupine will turn around, raise the quills and lash out to threat with its tail. If the porcupine hits an animal, the quills become embedded. Body heat makes the barbs expand and they become even more deeply embedded. If an animal is hit in a vital place, the wounded animal may die. Reportedly, a quill had perforated a man’s intestine and caused death. Infections seldom occur from quills since they have antibiotic properties.
These pests are unusually vocal during mating season. Males become somewhat aggressive and frequently battle over available females. They exhibit an elaborate mating display and sprays urine on the head of the female (disgusting but apparently effective!). Mating typically occurs in the fall and the young is born (one young only) seven months later. At birth, the young’s quills are soft but harden in about an hour. The newborn is quite well-developed and can forage for food within a few days.
The quills of newborn are well-developed, but apparently do not harm the mother because of the placental sac and their high moisture content. The porcupine newborn weigh approximately 1 one pound. They grow very rapidly and double the weight in the first 2 weeks. Although these young can flick their tails within an hour of birth, it is of important for them to hide at this point. Young porcupines are almost odorless, and as a consequence are not readily detected by predators. In addition the mother readily consumes any of their feces and thus eliminates any fecal odor which might attract predators. The female nurses the young via a pair of nipples located under the armpits and an additional pair on the abdomen. The female sits upright on her back legs and tail, thus allowing the newborn free access to these nipples. Nursing lasts around four months following a nine-month gestation period.
Adult females rarely travel any appreciable distance from the offspring during the first 6 weeks after birth. Young porcupines can quickly learn to climb and typically start with saplings, but these sized trees are often difficult for adults to climb and, as a result, the mother and infant meet only at night on the ground. Generally, adult female sleep in a resting tree during the day, with the baby unexposed on the ground in slash piles, rock crevices, or hollow bases of a tree. As the young mature, the distance kept between them and their mothers during daily food searches increases. The mother invariably returns to the young at night, commonly from as far away as ½ mile. The young porcupines learn the locations of their mother hiding places, locations of shelters, dens and food trees.
Male offspring may or may not remain within the home range of the female in the fall, but the mother typically avoids these young at this time on. As a result, young porcupines are on their own during the first winter and normally reach sexual maturity by their third year of existence. Significantly, male porcupines frequently mate with more than one female since reproductive rates are low.
Porcupines typically have a low mortality rate and live an average of seven to 8 years. Common causes of death are human predation, injury, disease, and winter stress. Infestation with the mite Sarcoptes scabiei, (scabies) commonly results in death of porcupines; other parasites include tapeworms, nematodes, lice, and ticks, Prolonged sub-zero winter temperatures may kill these animals as well as heavy snow packs, which limits their access to food. In some cases, porcupines injure themselves falling from trees. They have relatively few predators, although fishers are most likely the most efficient at killing these animals. Fishers can readily flip a porcupine thus exposing the soft, quillless ventral side. However, fishers are frequently fatally injured during this encounter. Other natural predators include coyotes, horned owls, mountain lions, bobcats, martens, foxes and black bears.
Adult Fisher. An efficient predator of porcupines. Public Domain. USFWS
A number of states have protective measures for porcupines because of their vulnerability to human harvesting. Others classify porcupines as a “predatory animal” and can be taken without a license in any manner and at any time.
Prevention and Control. Generally, any forest management technique that enhances closed canopy tree stands minimizes porcupine populations. With such conditions, there is limited understory vegetation, resulting in reduced food for porcupines. These conditions restrict porcupine numbers by reducing reproductive potential, encourage development of larger home-range areas, and increase winter mortality from stress-related causes due to nutritional deficiencies. Recent theories suggest practices that open canopy cover, such as prescribed burning and timber harvest, result in more favorable habitat conditions and attract natural porcupine predators. Increased predator densities may suppress porcupine populations as well.
Fencing can be a preventive measure but has limited use because it is a relative expensive technique. However, this technique can be cost-effective in certain areas or conditions where these pests are causing damage to high value crops or certain situations such as commercial tree plantations, and nut and fruit orchards. Fencing porcupines from gardens, orchards and small tree plantings can be accomplished with some changes. These pests can readily climb fences, but an overhanging wire strip at the top at a sixty five degree angle will typically discourage this behavior. A combination fence constructed of 18 inch poultry fencing, topped with a 11/2 inches long smooth electric wire, will also discourage climbing porcupines.
Repellents. There is a hot sauce based repellent that is registered to protect plastic tubing from porcupines gnawing. An additional repellent, Thiram is registered for other pests such as rabbits and squirrels-its effectiveness on porcupine is undocumented. Thiram is sprayed or painted on plants to prevent damage. When plywood is coated with a wood preservative, it is said deter porcupines from gnawing for its salt content. A more realistic approach would be provide a salt source, since gnawing on plywood serves to satisfy a salt craving. A short picket fence can be constructed of salt-impregnated wood sticks, thus offering a good “salt lick” for porcupines.
Biological Options. It has been suggested that porcupines cause more damage if livestock overgrazing removes preferred summer forage. If true, light livestock grazing could be used to stimulate additional herbaceous forage production (used by porcupines as a food source) and as a result minimizing damage to tree from these pests. Increasing predation in a given area is a possible biological control option. Excessive killing and trapping of natural predators, such as coyotes, mountain lions and fishers, could increase porcupine numbers. As a consequence, fishers have been released in several states including Oregon, California, Montana, Idaho, Vermont, Wisconsin, and New York. These releases were not done in order to control porcupine populations specifically; however, Michigan researchers indicated these fishers appeared to decrease porcupine numbers.
Live Trapping. Live trapping these pests is effective and easy for individual animals damaging small orchards, gardens or ornamental trees. Commercial traps or homemade box traps baited with salt-soaked materials works quite well. Once trapped, porcupines should be relocated a minimum of 25 miles away in order to prevent their return. Porcupines also can also be caught by placing a suitably sized garbage can over them and subsequently sliding the lid under the can, and turning the can upright. An equally effective technique is using a cone constructed of wire fencing material to invert over the animal. Of course, with these techniques it is a good idea to stay away from the tail and use thick rubber gloves to handle the animal.
Direct Control. Of course non-lethal techniques are preferred for porcupine control. But, if extensive damage is occurring or when non-lethal techniques are not working in the case of individual problem animals, shooting is an easy and of course effective mean of control. Porcupines are considered non-game animals and are not protected. Lethal control should be limited to individual animals causing the damage. However, shooting is effective when justified. Hunting during late-spring and summer is an effective time for harvesting animals feeding on herbaceous ground vegetation, irrigated crops, and orchard trees. Hunting during the fall and early winter may also reduce colonization; however, this usually has less impact on porcupine populations than does summer shooting.
Where legal a No. 2 or 3 steel leg hold traps are effective or No. 220 or 330 Conibear body gripping traps baited with salted objects are equally effective. Traps should be placed near the entrance of active dens or along well-used trails.
Depending on the state, lethal control of porcupines (shooting) should be limited to individual animals causing the damage. However, shooting is effective when justified. Hunting during late-spring and summer is an effective time for harvesting animals feeding on herbaceous ground vegetation, irrigated crops, and orchard trees.
Hunting porcupines during the fall and early winter may also reduce colonization; however, this usually has less impact on porcupine populations than does summer shooting.
True/False Test Questions.
1. Porcupines are nocturnal and typically active year-round spending much of their time resting in trees called “rest trees." Symptoms of the presence of an active den or resting tree are broken quills, fresh scats or feces, and the strong odor of their urine
2. Generally, any forest management technique that enhances closed canopy tree stands minimizes porcupine populations. With such conditions, there is limited understory vegetation, resulting in reduced food for porcupines. These conditions restrict porcupine numbers by reducing reproductive potential, encourage development of larger home-range areas, and increase winter mortality from stress-related causes due to nutritional deficiencies
3. A number of states have protective measures for porcupines because of their vulnerability to human harvesting. Others classify porcupines as a “predatory animal” and can be taken without a license in any manner and at any time.
4. Porcupines seek salt and find it in plants, road salt, salt-enriched soils, wood, and various other sources. Reportedly, these pests occasionally eat mud in salty-soil areas and consume various plants, such as aquatic liverwort and yellow water lily, both of which have a high salt content.
5. Fresh animal bones, plywood, human-handled wood posts, timbers, old shoes and boots, paint, and the outer bark all contain salt. Any object impregnated with urine also attracts porcupines because of the salt content.
Raccoons (Procyon lotor)
The raccoon (Procyon lotor) is also known as North American raccoon, northern raccoon, common raccoon and in the south coon. It is a moderate-sized mammal which is native to North America. Originally this species was typically found in deciduous and mixed forests, but because of their adaptability they have greatly increased their range to include coastal marshes, mountainous areas, and many suburban and urban locations, where they are considered pests. Due to deliberate introductions and escapes in the mid-1900s, these critters are now also found across the Europe, Japan, and the Caucasus region.
North American raccoon. Image courtesy David Menke, Wikimedia Commons. Public Domain
Identification. The total length of these critters (not including tails) ranges from 16 and 28 inches. Their tail length ranges from 8 and 16 inches. Depending on habitat, their adult body weight body varies considerably from 4 to 30 pounds. On an average, males are approximately 20% heavier than females. At the beginning of winter, a raccoon can weigh twice as much as in spring because of fat storage
These critters were originally thought to be solitary, but there are now indications that they exhibit gender-specific social behavior. In doing so, females frequently share common areas. Up to four unrelated males are commonly found together. These congregations function to possibly defer foreign males during the mating season and other possible invaders of their territory. The size of their home range varies from a half dozen acres for females in urban areas to 20 square miles for males in rangeland and parries. It is thought that odor is used to mark and establishing territories and identify individuals.
Raccoons have a gestation period of about 65 days with 2 to 5 young (kits) born in spring. The mother subsequently cares for the young until late fall. Reportedly, captive raccoons can live for up to 20 years with wild individuals surviving 1.8 to 3.1 years. Traffic accidents and hunting are the two most common means of unnatural death for these mammals.
A characteristic physical feature of this critter is the area of black fur surrounding their eyes which contrast the surrounding white face. This could be described as a “bandit's mask" and has possibly led to this animals reputation as mischievous. The roundish ears are also rimed by white fur. The dark mask may serve to reduce glare and thus enhance night vision. The body has stiff, elongated guard hairs that function to repel moisture and are typically gray mixed with a few brown. Raccoons possess dense under-fur which makes up nearly 90% of the coat and function to effectively insulate the animal against cold weather.
Raccoons can stand on their relatively short hind legs and readily examine objects with their front paws. They are relatively slow moving and do not run quickly or jump great distances. These critters are swimmers and able to remain in water for extended periods of time. Raccoons can climb down trees head first. In order to accomplish this unusual feat, they rotate their hind feet so that they point backwards. Unlike many mammals, they are able to both sweat and pant for heat dissipation.
Raccoons have a good sense of touch. The "hyper sensitive" front paws are protected by a thin horny layer which becomes pliable when wet. The 5 digits of the paws have no webbing between them, which is unusual for a carnivore. Almost two-thirds of the area responsible for sensory perception in the raccoon's cerebral cortex is specialized for the interpretation of tactile impulses, more than in any other studied animal. Little has been conducted to determine the mental capabilities of these animals with the majority dealing with their sense of touch. In one study these critters opened eleven of thirteen complex locks in fewer than 10 attempts and easily repeated the process when the locks were turned upside down or rearranged. As a result, it was concluded that raccoons understood the locking mechanisms and that their speed of learning was equated to that of a rhesus macaque (a smart monkey!).
Though typically considered nocturnal, these mammals may also be diurnal if needed to locate available food. Raccoons are somewhat omnivorous with their diet which consists of about 40 percent invertebrates, 33 % plant material and 27 % vertebrates. In the spring and early summer months, they feed on insects, worms, and other animals that are commonly available early in the year. They prefer nuts and fruit, such as walnuts and acorns which become available in late summer and autumn and are important sources needed to build up fat reserved for winter. Unlike it is commonly thought, raccoons do not eat large or active prey such as mammals or birds, but are more attracted to prey which is easier to catch, specifically amphibians, crayfish, and fish. These vermin exhibit a winter rest by reducing their activity, especially during long and permanent snow cover.
Raccoons use their front paws to sample, examine and clean various objects including food. The sensitivity of this behavior is increased if this is performed underwater, since water softens the horny layer covering the paws. However, this behavior is quite common in captive coons but has not been observed in the wild. The theory is that washing food is imitating foraging for aquatic foods.
Raccoons usually mate between late January and mid-March with gestation lasting 63 to 65 days. Litters typically consist of two to five young with larger litters occurring in areas characterized by high mortality rates as a result of severe winter and hunting. Males do not participate in caring for and raising young. The kits or cubs are deaf and but their mask is fully visible thus of use in identification. Once reaching about 2 lbs., the kits start to consume solid food, explore, and feed on the ground. Subsequently suckling gradually decreases followed with weaning at around 16 weeks. In the fall, once trained by the mother as to den construction and feeding behavior, the kits break up. Many of the new females remain close to the home range of their mother. On the other hand, new males are less likely to do so and can establish new home ranges as far as 12 miles away.
Captive raccoons are typically long lived for up to 20 years. On the other hand, wild individuals typically survive only 1.8 to 3.1 years. This is of course greatly influenced by factors such as weather, hunting and traffic. Approximately only half of newborns survived a year. Subsequently their mortality rate drops to between 10 and 30% annually. Young raccoons commonly lose their mother resulting in starvation. Distemper is the most frequent natural cause of raccoon death in U.S. It is not uncommon for epidemics of this disease to basically eliminate local populations of these critters. Heavy traffic accidents and or heavy hunting can cause up to ninety percent of raccoon deaths. The most common predators (exclusive of humans) of raccoons are coyotes, great horned owls, and bobcats.
Although they have thrived in sparsely wooded areas in the last decades, raccoons depend on vertical structures to climb when they feel threatened. Therefore, they avoid open terrain and areas with high concentrations of beech trees since the bark of these trees is too smooth to climb. Tree hollows in old oaks or other trees and rock crevices are preferred by raccoons as sleeping, winter and litter dens. If such dens are unavailable or accessing them is inconvenient, raccoons utilize burrows dug by other mammals, dense undergrowth, roadside culverts in urban areas, or tree crotches. Since amphibians, crustaceans, and other aquatic animals are an important part of the raccoon's diet, lowland deciduous or mixed forests abundant with water and marshes sustain the highest population densities of these critters.
Due to its adaptability, the raccoon has been able to use urban areas as a common habitat. Home range sizes of urban raccoons are only 7 1⁄2 to 100 acres for females and 20 to 200 acres for males. In small towns and suburbs, many raccoons sleep in a nearby forest after foraging in the settlement area. Fruit and insects in gardens and leftovers in municipal waste are easily available food sources. Furthermore, a large number of additional sleeping areas exist in these areas, such as hollows in old garden trees, cottages, garages, abandoned houses, and attics.
In the U.S., raccoons in urban areas are on the increase. As a result their presence, human reaction is quite variable and ranges from outrage to deliberate feeding. Authorities typically suggest to not feed wild animals because they might become increasingly obtrusive and dependent and learn not to fear humans. Since they do vector rabies, this is not a good idea, especially in areas where this disease is present. Raccoons attacking humans are extremely rare and are typically a consequence of the animal feeling threatened. Raccoons typically do not prey on dogs or cats, but there are individual documented cases. In urban situations, they are mainly nuisance pests (feeding on fruit trees, overturning garbage cans). On the other hand, raccoon damage as a result of their use of attic space as dens can run into thousands of dollars.
Control. Killing or relocating these animals without a permit is forbidden in many urban locations. These methods typically are only of value to remove particularly wild or aggressive individuals, since dens (such as in attics) are either known to several raccoons or will quickly be rediscovered. Scare devices such as flashing lights and loud noises can be effective in repelling females and their young prior to when they would normally leave a nesting location-e.g. when cubs are 8 weeks old.
Extensive hunting has a minimal effect on solving problems with raccoons since if needed they are capable of increasing their reproductive capacity (certain limit) and thus over time readily replace hunted individuals. The costs of large-scale eradication programs are typically not cost effective, especially considering the overall minimal damage these mammals cause.
There are commercially available chemical repellents that have limited value in repelling raccoons from attics, and other locations. Pest control applicators chiefly use traps to eliminate long term problems. In addition, soil drench insecticides can be used to kill insect grubs and worm. This functions to prevent moles and raccoons from digging in lawns in search of these food sources.
Raccoons which den near or in the attics of homes should be trapped. If not they will reproduce and over time and their offspring will eventually move into the same location. A big mistake is to try to seal raccoons off once they have established a den in an attic. Sealing them will likely result in angry, aggressive animals that will do anything to escape, including tearing shingles off of the roof or an animal that may end up inside the living area of the home. If an animal is sealed on the outside of the structure, it will attempt to chew its way back in, causing additional damage.
There are a number of commercial live traps. Traps do not necessarily need to be located in established path of these animals but should be placed in the vicinity of their normal location. Traps should be secured as these critters are known to tip over traps in attempts to escape. Common baits for these pests include a variety of commercial baits, fresh fruit, eggs, fish, meat or whatever they are currently feeding upon.
6. Killing or relocating raccoons without a permit is forbidden in many urban locations.
7. Extensive hunting has a minimal effect on solving problems with raccoons since if needed they are capable of increasing their reproductive capacity (certain limit) and thus over time readily replace hunted individuals.
8. Raccoons often den near or in the attics of homes. These should be trapped. If not they will reproduce and over time and their offspring will eventually move into the same location. Abig mistake is to try to seal raccoons off once they have established a den in an attic. Sealing them will likely result in angry, aggressive animals that will do anything to escape, including tearing shingles off of the roof or an animal that may end up inside the living area of the home. If an animal is sealed on the outside of the structure, it will attempt to chew its way back in, causing additional damag
9. Captive raccoons are typically long lived for up to 30 years. On the other hand, wild individuals typically survive only 5 to 8 years.
Coyotes (Canis latrans)
Coyotes are readily recognized to the average individual. They are a medium-sized member of the dog family that also includes wolves and foxes. With its pointed ears, slender muzzle, and drooping bushy tail, the coyote often resembles a German shepherd or collie. Coyotes are usually a grayish brown with reddish tinges behind the ears and around the face, but coloration can vary from a silver-gray to black. Most have dark or black guard hairs over their back and tail. The tail usually has a black tip. Eyes are a striking yellow, with large dark pupils, rather than brown like many dogs. While coyotes are capable of interbreeding with domestic dogs, hybrids (known as coydogs) are generally rare. Most adults weigh between 25 and 35 lbs., although their heavy coats often make them appear larger. There have been suggestions that urban coyotes are larger than rural coyotes, but there is no evidence of this.
Coyote. Image courtesy Yathin S Krishnappa CC BY-SA 3.0
Range. Historically, coyotes were found in much of the western United States (U.S.). Over the last 60 years they have greatly extended their range to cover a large part of North America. Coyotes are quite adaptable and are capable of thriving in almost any habitat in California from the coast to arid deserts. They are typically not as commonly found in locations such as dense forests or agricultural crops due to a under abundance of food sources. These pests are dependent upon food resources for breeding, and pup rearing. In situations where food is readily available, their territories are smaller. Territories can range from as large as 15 square miles to as small as one-square mile or even one 1/4 square mile. Packs consist of up to 10 individuals with dominant pairs sharing its area with juvenile offspring. Coyotes are not nearly as social as wolves and can live successfully as solitary individuals.
Habitat. Reportedly, these pests were originally found in relatively open habitats, especially lightly wooded areas and grasslands of the western U.S. However, these pests have adapted and are currently found in almost every type of habitat including the arctic to tropics of North America. Coyotes live in swamps, tundra, grasslands, deserts, brush, and forests. They are found in all altitudes ranging from high mountain ranges to below sea level. High densities of these pests also appear in the suburbs of Orange County (including Huntington Beach where I live), Los Angeles, Orange, Pasadena, San Diego, Phoenix, and many, many other western cities.
Food Habits. Coyotes are extremely omnivorous and feed on a variety of vegetables, fruit, meat, garbage and other food products. Ground squirrels and rabbits make up a large component of their diet, possible because they are so common in many areas and relatively easy to catch. Rodents, carrion, insects, ungulates (usually fawns), as well as poultry and livestock are also consumed. These pests readily seek fruits such as berries, watermelons and other vegetative matter that is available. In many areas, these pests feed on human refuse at dump sites and readily catch and consume pets (cats and dogs).
These predators prefer prey that is the easiest to catch including animals that are wild, sick, inexperienced, old, domesticated or weakened. With domestic animals such as cat and dogs, they can readily catch and kill young, healthy, and in some instances adult prey, even on occasion very large dogs. They are quite intelligent and clever and frequently select their prey based on behavioral characteristics. As an example, healthy strong lambs are selected from flocks even though weaker lambs are present. In such situations, stronger lambs are typically found on the outside of a flock and quite active while a weaker lamb is typically located towards the center of a flock and relatively immobile.
Coyotes are presently the most abundant livestock predators in western North America, causing the majority of sheep, goat, and cattle losses. Coyotes will typically attack their prey’s throat behind the jaw and under the ear when attacking adult goats, sheep, and dogs with death commonly resulting from suffocation. The loss of blood is typically a secondary cause of death in these cases. Calves and sheep are killed by attacking the animal’s hind-quarters resulting shock and blood loss. When attacking smaller prey, such as small dogs, cats and young lambs, they attack the skull and spinal regions thus resulting in massive tissue damage. Small (such as cats and small dogs) or young prey may be completely carried off, leaving only blood as evidence of a kill. Once consuming their prey, these predators will typically leave the hide and most of the skeleton of larger animals relatively intact, unless food is scarce, in which case they may leave only the largest bones.
Coyote attacks can typically be distinguished from coydog or dog attack by the fact that the former partially consume their victims. Tracks can also be of value in making this distinction. Coyote tracks are more oval in shaped and compact than those produced by domestic dogs. In addition, their claw marks are less prominent and the tracks tend to follow a straight line more closely as opposed to those of domestic dogs. With the exception of sight hounds (e.g. Irish wolf hounds, grey hound, whippets, Russian wolf-hounds), most domestic dogs with similar weight of coyotes produce a slightly shorter stride. Coyote predation can be distinguished from wolf predation in that with the former, there is less damage to the underlying tissues.
These predators have become a major problem in attacking a variety of pets in urban and suburban situations. Weekly, three to five pets attacked by coyotes are brought to the Animal Urgent Care Hospital of south Orange County (California), the majority of which are dogs because cats normally do not survive their attacks. Scat analysis collected near Claremont, California revealed that coyotes relied heavily on pets as a food source in winter and spring. At one location in southern California, coyotes began relying on a colony of feral cats as a food source. Over time, the coyotes killed most of the cats, and then continued to eat the cat food placed daily at the colony site by citizens. Coyotes attack smaller or similar sized dogs, but they have been known to attack even large, powerful breeds like the Rottweiler in exceptional cases. Dogs larger than coyotes are generally able to drive them off, and have been known to kill coyotes. Smaller breeds are more likely to suffer injury or death.
Other factors come into play as far as when coyote predation typically occurs. Livestock coyote predation typically occurs more commonly during early spring and summer rather than the winter. Livestock is usually under more intensive management during winter, either in feedlots or in pastures. This typically equates to nearby human activity, a situation that some coyotes attempt to avoid. Also coyotes, as with most predators, produce their young in the spring and raise them through the summer, a process that demands increased nutritional input. This increased demand corresponds to the time when young sheep or beef calves are on pastures or rangeland and are most vulnerable to attack. Coyote predation also may increase during the fall when young coyotes disperse from their home ranges and establish new territories.
General Biology, Reproduction, and Behavior. Coyotes are mostly nocturnal and or crepuscular (early morning hours). This is especially true in urban situations or other situations where human activity occurs. Where there is minimal human interference and during cool weather, they may be active throughout the day.
At night, these pests emit a series of high pitched and short yips and howls. Howls function to keep individuals in touch with each other. Howling also has a territorial function of basically saying “I am here and this is my area”. Of course the message to other is to stay away but females are enticed to follow the sound. Yelping is interpreted as a celebration or criticism within a small group of these animals. This is often heard during play among pups or young animals. The bark is interpreted as a threat and is often produced when a coyote is protecting a kill or den. Huffing is thought to be used in calling pups without making a great deal of noise.
Coyotes rest and sleep in sheltered areas but do not generally use dens except when raising young. They possess excellent eyesight, hearing, and a keen sense of smell. They are very tough and hardy with excellent recuperative powers. They are quite fleet of foot having been measured at speeds of up to 40 miles per hour and can sustain slower speeds for several miles.
The mating season of these vermin begins in January when several male coyotes gather in the vicinity of and court a single female, but she ultimately mates only one. Once mated the male desert coyote may travel with the female. The female has one generation a year with three to nine puppies, usually in the spring when food is readily available. The gestation period is around two months. The pups are born with eyes closed in a den, but their eyes open after about two weeks and they emerge from the den a couple of days later. The male provides regurgitated food for the pups but is not allowed in the den. The pups play and live in the den until they are six to 10 weeks old at which point the female begin to include them on foraging trips. The family typically disbands by fall when the young are usually hunting alone. Within a year, they leave the den and stake out their own territory which they mark with urine.
As noted earlier, coyotes are capable of hybridizing with dogs and wolves, but this is unlikely. When interbreeding with domestic dogs does occur survival of the offspring is low. Typically, the breeding cycle of coy dogs doesn’t correspond to the breeding cycle of coyotes; thus, further breeding with coyotes is unlikely, even though coy dogs can reproduce.
Coyote dens typically occur in protected locations such as in rock crevices, steep banks, under brush, in sinkholes and other similar open situations. As might be suspected, these dens are normally located less than a mile from water depending on circumstances. It is not uncommon for them to expand holes that have been dug by smaller burrowing animals such as ground squirrels. Dens vary from a few to 50 feet in length and may have several openings.
Both sexes hunt and provide food to the young for several weeks after birth. In addition, other adults associated with parent coyotes may also help in feeding and caring for the young. Coyotes commonly hunt as singles or pairs and can travel extensively in their hunting forays. They will frequently forage in the same area provided food is plentiful. They occasionally bury uneaten food for later use.
Coyotes in Urban Situations. Coyotes are one of the few predators that have increased their presence since mankind has encroached on their territories. Initially they mainly occurred in parts of western North America, but now have adapted and even thrived in the presence of human populations. Since the early 1800s, their distribution in the U.S. has greatly increased. Sightings of these predators now commonly occur in Wisconsin, Michigan, Oregon, California, New England, New York and eastern Canada. Coyotes now occur in nearly every continental state and Alaska and currently have occupied most of the areas previously dominated by wolves. It is not at all unusual to see them foraging throughout urban situations.
Due to their relatively small size, coyotes rarely attack humans or cause serious injuries. However, human coyote attacks have increased since 1998 in California. Data from the California Fish and Game, USDA, Fish and Wildlife Services, and other sources indicate that while 41 attacks were recorded during the period of 1988-1997 and 48 attacks were verified from 1998 through 2003. The majority of these incidents were in southern California and near the suburban-wild-land interfaces.
Due to the lack of harassment by residents, urban coyotes lose their natural fear of humans. This behavior is enhanced by humans intentionally feeding coyotes. As a result, certain coyotes may act aggressively toward humans, chasing bicyclists and joggers, stalking small children, and confronting people walking their dogs. As with wolves, healthy coyotes typically target small children, mostly under the age of 10, though there are numerous instances of them biting adults.
There are only two documented fatalities in North America from coyote attacks. In 1981 in Glendale, California, a coyote attacked a two-year-old who was saved by her father but died as a result of blood loss and a broken neck. In October, 2009, a 19-year-old folk singer died from injuries sustained in an attack by a pair of “coyotes” when hiking in Nova Scotia, Canada. Recent studies now indicate that the animals responsible for this attack and subsequent deaths may have been from coyote-wolf hybrids.
Peoples increase the possibility of conflicts with coyotes by inadvertently or intentionally feeding them, whether providing access to food sources such as pet food, garbage, or livestock carcasses or feeding them on purpose. In these cases, coyotes quickly lose their innate fear of humans and become aggressive. They also become dependent on the easy food sources people provide. Once a coyote does not hunt its own and loses the fear of humans, it may become dangerous and attack without warning.
Prevention is first and possibly best step in minimizing human conflicts with coyotes and other wildlife. The following management strategies around neighborhood communities should be encouraged:
1. Avoid leaving small children unattended where coyotes are frequently seen or heard.
2. In areas where coyotes are known to occur, children should be aware of what to do if an encounter occurs. If a coyote approaches, do not run, but be as loud (shout a predetermined phrase) and seem as big as possible.
3. If a coyote is encountered, children should inform nearby adults of the coyote’s presence as opposed to a general scream.
4. Do not feed coyotes. If this is done, these predators tend to lose their natural fear of humans and frequently develop a territorial attitude that may lead to aggressiveness. Coyotes are omnivorous, scavenger and will consume many types of food including fruit. As a result, fruit trees should be fenced, or fallen fruit should be disposed of or eaten regularly. Since they are scavengers, some material in compost pile is fair game. As a result, these piles should occur within a fenced area or securely covered. Newly composted material should be covered (soil or lime) in order to prevent it from smelling. Avoid including animal matter in composted material as it attracts coyotes.
5. Dogs and cats should be fed indoors. If fed outdoors, do so in the morning or at midday. Left-over pet food should be removed well before dark.
6. Avoid feeding feral cats (domestic cats gone wild) or other wild animals. Coyotes prey on these cats as well as any food provided for them. Avoid the accumulation of seed under bird feeders. These predator/scavengers will eat bird food and additionally are attracted to birds and rodents (e.g. .rats, mice, and ground squirrels) that come to feeders.
7. Keep pets indoors, especially at night. In suburban and urban areas, coyotes quickly learn to hunt and consume cats and small to medium sized dogs. Domesticated animals are unsuspecting and easy prey. Neighbors should be notified if a pet is lost to coyotes. Unfortunately, once a coyote finds easy picking, it will return to the same area looking for more.
8. Modify the landscape near and around play areas. Shrubs and trees should be cut several feet above the ground in order to prevent these predators from hiding in them.
9. An old hockey stick, broom handle, or stones, should be kept near the play areas as deterrents if needed.
10. If needed, a coyote proof fence can be constructed. Coyotes don’t normally jump over fences but instead grab the top with their front legs and push themselves upward and then over with their rear legs. A 5-foot metallic woven-wire fence with the top foot extended out wards at a 65 % angle should prevent these predators from reaching the top. The bottom of the fence should be buried at least 8 inches below the soil surface. Electric fences that are commercially available will keep coyotes out of an enclosed area. These fences do not need to be as tall as a woven-wire fence. A coyote’s first instinct will be to back off instead of jumping over them and will not attempt to dig under such a fence.
Damage and Damage Identification. Coyotes feeding can be very destructive to poultry, livestock, and some crops. In many cities, they have become a major problem since their populations have increased significantly with resultant predation on pets. They sometimes create problems relating to public health and safety when they frequent residential areas, airport runways and act as potential carriers of rabies and other diseases. In rural situations, the primary concern is predation on livestock.
Coyote attacking sheep. Image courtesy of USDA, Animal Plant Health Inspection Service,
Wildlife Research Center.
In 1999, NASS surveyed farmers and other producers and found that these predators killed an estimated 165,800 lambs and sheep (nationwide) valued at a total of $9.6 million. Feral dog and fox predation reportedly resulted in an additional 49,400 sheep and lamb deaths valued at $3.5 million. In addition, feral dogs, foxes and coyotes, killed around 36,000 goats valued at more than $1.8 million.
Feral dogs and coyotes also prey on calves and cattle. A NASS survey indicated that coyotes attacked and killed an estimated 95,000 calves and cattle valued $31.8 million in 2000. In addition, feral dogs preyed on and killed 26,000 calves and cattle valued at $9.5 million. In addition, these predators kill thousands of turkey, chickens, geese, ducks, and other birds every year.
Since coyotes frequently scavenge on dead livestock, the mere presence of tracks or feces close to carcasses is not necessarily an indication of predation; however, there are additional factors that can help to determine if this is the case. These may include blood, broken vegetation, drag marks or scrapes on the soil and in various spots around the site. The quantity of carcasses remains left after a kill varies considerably depending on how recently the kill was made, the size of the animal, the weather, and the number and species of predators that fed on the animal.
One characteristic in determining if an animal was killed by a predator is the presence or absence of subcutaneous bleeding at the point of attack. The point is that if a dead animal is bitten by a predator and bleeding does not occur, the animal’s death would not be the result of predation. Talon punctures from large birds of prey will also cause hemorrhage, but the location of these is usually at the top of the head, neck, or back. If enough of the carcass remains, the skin around the neck and head can be removed to examine for bleeding around the puncture wounds. This procedure becomes less indicative of predation as the age of the carcass increases or if the remains are scanty or scattered.
Dogs commonly do not attack and kill calves or sheep for a source of food and are significantly indiscriminate as to how and where they attack. Still, it is on occasion difficult to determine between coyote and dog kills without considering other factors such as size and spacing of tooth punctures and size of tracks. Coyotes tracks tend to follow a straighter path than a dog’s tracks; typically, their paw prints are more oval-shaped and their nail-marks are less prominent. When trotting the stride of a coyote’s averages 17 inches, which is normally longer than that of a dog of similar size and weight. Normally when dogs attack, they rip the hind quarter, flanks, and head, and may chew ears.
Legal Status. The status these predators depends primarily on state and local laws. In many states, including most of the western states, these animals are classified as predators and can be killed anytime of the year regardless if they are causing damage to livestock, agriculture or merely a nuisance pest. In other states, coyotes can only be killed certain times or seasons and then often only by specified methods, such as trapping. Night shooting with a spotlight is typically illegal. In some states, only state or federal agents using prescribed methods (such as snares) can catch coyotes. Some states allow killing coyotes that are otherwise protected, typically with special permits, and when it has been documented that they are attacking livestock. In some instances, producers can apply control methods, and in others, control must be managed by a federal or state agent. As indicated above the laws that regulate coyote control are not typically uniform among states or even in various counties within a state, and they can frequently change. A 1989 Supreme Court action determined that it is not legal to circumvent the laws relative to killing predators, even to protect (livestock) from predation.
Damage Prevention and Control. Successful control of coyotes typically involves a pest management approach, including good animal husbandry practices along with timely effective control methods. Regardless of the methods used to stop damage, the main emphasis should be aimed at preventing damage as opposed to elimination of these predators. It is important to prevent coyotes from killing farm animals for the first time because, once these predators have killed livestock, they will likely continue to do so until stopped.
Exclusion. Most of these predators can easily climb, cross through or dig under standard livestock fences. They are extremely intelligent and clever and total exclusion of all coyotes in a given area via fencing is highly unlikely. However, good well-constructed fencing can play an important role in reducing coyote predation.
Net-Wire Fencing. Net fences that are in good shape will prevent many of these predators from gaining access to a range land, pastures of other similar situation. The mesh should be less than 6 inches horizontally by less than 4 inches vertically. Because coyotes can readily dig under such a fence, barbed wire should be placed at ground level or a wire apron can be placed at the base. The fence should be around 6 feet high to discourage coyotes from jumping over it, although this is rare. Climbing a fence, which is more common in coyotes, can be discouraged by adding a charged wire at the top or installing a wire overhang.
Electric Fencing. Electric fencing which have been used for years for various reasons has been changed due to the use of new energizers and new designs from New Zealand and Australia. The chargers have high output with low impedance, present minimal fire damage, are resistant to grounding, and are typically safe for humans and livestock. The fences are typically constructed of high-tensile wire that is stretched to a tension of 200 to 300 pounds.
Fence extensions (above image) are required to keep coyotes from jumping over a 5-foot fence. Angle the top of a woven-wire fence out about 15 inches and completely around the fence. An effective fence extends below the surface, or has a wire apron in front of it to prevent digging.
A six-wire electric fence can keep coyotes out of an enclosed area.
Predators in general and more specifically coyotes at times become “trapped” inside electric fences. While attempting to cross an electrical fence, they will receive a shock as they enter and subsequently avoid the fence in order in attempts to escape. Occasionally, the animal may be readily seen and readily removed from the pasture or field, but in others, particularly in large acreage with rough terrain, the animal may be hard to remove.
Replacing older fences with newer electrical models can be considerable and possibly not cost effective. In situations where the existing fencing is in reasonably good condition, the simple addition of a few charged wires can greatly enhance the relative effectiveness of the fence to repel predators and also for controlling livestock. If these predators are climbing or jumping such a fence, charged wires can be placed on the top at various intervals along the fence. There are brackets that are commercially available that can be used to make this installation relatively simple. The number of additional wires depends on the predicted behavior of the predator and the design of the original fence.
Portable Electric Fencing. The use of safe, high-energy chargers and other equipment has resulted in the development of a number of portable electric fences. Most are made of strands of wire running through polyethylene twine or ribbon, commonly called polytape. This is available in multiple and single and rolls or as mesh fencing of different heights.
Fencing of either type can be effective if included with other types of control such as using dogs to guard the fenced area. If a coyote does get past a fence, the dogs can still deter it from attacking livestock while barking to warn the grower or producer.
Cultural Methods and Habitat Modification. Herd or Flock Health. Reportedly, healthy cows and sheep typically have higher reproductive capacities and normally lower death losses. Coyotes normally have a tendency to prey on smaller lambs. Poor nutrition typically eventually produces weaker or smaller offspring and logically increases predation. Sheep or cows in good condition, as a result of proper nutrition, will produce stronger young that are potentially less likely to experience predator attack.
Changing Season of Lambing or Calving. Since coyote breeding season occurs in the early summer through late fall, most predation by these animals follows this pattern due to the fact that these predators frequently seek food for their young. It follows that it may of beneficial to change timing of calving or lambing procedures (if possible). Reportedly, livestock producer have attempted to reduce the large number of young animals on hand during periods of coyote breeding, thus reducing the number of losses. In addition, producers that utilize smaller pastures, pens and even indoor situations experience less predation from coyotes than those that do not.
Protective Enclosures. As previously discussed, coyotes are primarily nocturnal predators. So it follows that well lighted structures that contain livestock give them added protection. Coyotes tend to seek prey on foggy or rainy days more than on sunny days. Keeping the sheep penned on foggy or rainy days may also be helpful.
Removal Dead Animals. Coyotes are basically scavengers and given a choice will feed more readily on dead animals than preying on a living animal. If follows that carrion tends to attracts coyotes to a given area thus increasing the chance of predation. Some growers feel that if an abundant amount of carrion is always present reduced predation will occur. A study in Canada indicated that the removal of livestock carcasses significantly reduced overwinter coyote populations and shifted coyote distributions out of livestock areas.
Habitat Modification. As a rule, the more open the area where livestock are kept, the less likely those coyote losses will occur. Junk piles are very frequently located near farms, thus providing excellent habitats for rabbits, rats, ground squirrels, mice and other prey. Coyotes may be drawn to these areas, hence close to livestock, thus increasing the possibility livestock predation. For this reason, removal of junk piles, wood, and other unnecessary materials seems to an excellent management practice. Also, certain crops attract rats, ground squirrels, and rabbits, which in turn attract coyotes. The elimination of these rodents may reduce the . presence of coyotes.
Frightening Devices and Repellents. There are several devices that are available for attempting to scare or repel coyotes from a given location. Generally speaking, these can be somewhat effective provided a few criteria are met. Once a coyote becomes well-established in a given area, it is much less likely to be “scared off’ as opposed to a coyote that is new to the same location. In addition, these predators eventually acclimate (get used to) to such devices over time. As a result, if a scare device is used continuously in a given location, coyotes will eventually adapt to its presence and the device will lose its effectiveness. As a result, sporadically using a variety of these types of devices in an area is far more effective than using one continuously. The effectiveness of these devices has been question over time. The devices discussed below have met with varying degrees of success.
Vehicles. Parking vehicles where coyote’s activity (predation) has occurred reportedly temporarily reduces predation. The effectiveness of this process can be increased by periodically relocating these vehicles to nearby locations. Placing a replica of a person in the vehicle has been tried with limited or undocumented success. If not successful, the vehicle can serves as a comfortable blind in which to wait and shoot coyotes. Propane canons or exploders produce loud explosions with ignition of propane gas. Generally speaking, the time between explosions can vary from about 1 minute to 15 minutes.
Electronic Guard. Developed by the Animal and Plant Health Inspection Services' (APHIS) Wildlife Services (WS) program, the Electronic Guard Frightening Device combines two scare tactics, sound and light. Although it was created by WS' National Wildlife Research Center (NWRC) to protect sheep from coyote predation, the Electronic Guard can be used to protect other livestock and commodities from wildlife damage.
A photo sensor activates the Electronic Guard at nightfall and turns it off after daybreak, and as a consequence, it is activated when predation is most common. A timer controls a siren and a strobe light—activating the strobe light or siren or both at once. This randomization of mechanisms thus enhances the effectiveness of the device. Reportedly, use of this device can temporarily reduce coyote predation an average of 60 % in mountain grazing areas and 80 % in pastures and rangeland.
Historically, livestock farmer have used a variety of frightening devices to ward off potential predators, including coyotes. Coyotes are initially fearful of unexpected disturbances such as the Guard and keep their distance. Over the years, the devices have changed from simple scarecrows and bells or other noisemakers to more modern devices like the Electronic Guard.
As with many frightening devices, the Guard has limited uses because most predators including coyotes adapt to the periodic light-and-sound show. This device is certainly not a cure-all for predation problems but is one of several tools available in an integrated control approach. It may help producers complete the lambing season with minimal loss, or at least stopping coyote predation until sheep can be moved or until other control methods can be used.
Reportedly, this device has been successful in preventing black bears from entering vineyards and white-tailed deer out of cornfields and gardens. There are also reports that the Guard prevents damage to orchards and haystack by deer and elk. It also discourages beavers from building dams, and frightens birds from commercial fish farms. The number of Guards required to protect sheep of course depends on the size of the area to be protected, the number of sheep, the vegetation in or around it, and the terrain. Generally speaking, a minimum of two units should be used in relatively small, fenced pastures (20-30 acres) or in flat pastures with short grass. Three or four units should be used in hilly or wooded pastures, those with tall grass or large, fenced pastures (31-100 acres). In open-range conditions, the number of Guards depends on the size of the location and number of sheep. NWRC testing indicates that a minimum 4 guards should be used with a band of 1,000 ewes and their lambs.
Guard Dogs. A good guard dog can protect sheep and goats from coyote damage. Larger breeds, such as Komodor, Great Pyrenees, Anatolian shepherd and Akbash, often work well to intimidate much smaller coyotes. These dogs ideally should be acquired as puppies and introduced to the flock or herd at as early age as possible. Human contact should be as minimized as possible. If these dogs are treated as pets, they will typically not adequately bond with livestock and their possible effectiveness could be reduced. On the other hand, the dog needs to be tame enough so that can be handled enough for vaccinations, worming and other care. Dogs have individual personalities with one dog readily bonding to goats and sheep while another may not. A good guard dog will remain with livestock constantly and readily confront predators that approach. Guard dogs typically require a considerable amount of training and require food and shelter in the field. Initially a dog may be quite effective and be less effective later. On occasion, guard dogs have been responsible for killing sheep.
Donkeys. Donkeys are gaining in popularity in the U. S. for guarding goats and sheep against predators, including coyotes. Reportedly in Texas, almost 25% of 11,000 goat and sheep farmers have used guard donkeys. A single donkey, usually a female, sometimes a gelding (jacks typically are used with lambs) is introduced to the herd and undergoes a bonding stage, as discussed with guard dogs. After a donkey has bonded with sheep, it will protect them from potential predators such as coyotes, foxes and dog as aggressively as it would protect its own young. This is very important in locations where the sheep graze over large areas
Generally, donkeys are relatively docile with humans, but they appear to have an inborn dislike of dogs, foxes and coyotes. An often quoted advantage of the donkey as compared to guard dogs is that donkeys readily eat the same food as sheep and they will also sleep with them at night. If waken or disturbed by a predator, donkeys voice a warning to the flock which alerts them to danger. Subsequently, the donkey will chase and often trample the predator. Other responses can include bared teeth, braying, biting, and a running attack. Mammoth donkeys are usually too slow and miniature donkeys are not usually big enough to handle coyotes. Reported success of donkeys in reducing predation is highly variable. Improper husbandry and unrealistic expectations probably account for many failures. Donkeys are significantly cheaper to obtain and care for than guard dogs, and they are probably less prone to accidental death and premature mortality than dogs.
Llamas. As with donkeys, these have an inborn dislike of coyotes, foxes and dogs (canines in general), and an increasing number of livestock producers are using llamas to protect their sheep. Reportedly 145 ranches that used guard llamas to protect sheep indicated that losses to predators decreased by over three-fold per year. These ranchers surveyed were “very satisfied” or “satisfied” (80%) with their llamas. These animals reportedly bond with sheep within hours and have the same advantages (discussed above) as guarding dogs and similar to those described for donkeys.
Toxicants. Pesticides are a significant component in minimizing coyote damage, but currently their use is extremely restricted by federal and state laws. All pesticides used in the U. S. must be registered with the EPA and must be used as prescribed by label directions. The two toxicants currently registered with the EPA for coyote (and other mammalian predators) damage control is sodium cyanide which is incorporated in the M-44 ejector device, and Compound 1080 (sodium monofluoroacetate) which is incorporated in livestock protection collar. These products are restricted use pesticides and consequently can only be used by certified pest control applicators. As uses of various products can vary from state to state, Information on registration status and availability of these products in individual states should be obtained from the respective state’s department of agriculture.
M-44. The M–44 is a tool used by the Wildlife Services (WS) program of the USDA and APHIS to protect livestock and poultry, as well as threatened and endangered species, from feral dogs, coyotes, and foxes. In addition, this product is registered for the control of mammalian disease vectors that carry rabies. The use of this product is effective, safe (if used as prescribed), environmentally friendly and registered by the EPA and can only be used by trained and certified applicators. All M–44's that are used in WS field conditions are well-marked and must be checked by trained personnel at least once a week. The overwhelming use of this product is for coyote damage control. The devices are located along game trails, livestock trails, ridges, along fence lines and near seldom-used ranch roads. This product is used mostly in the spring and winter but depending on location and weather can be used throughout the year. This device functions by ejecting sodium cyanide powder into the mouth of the predator. This injection is triggered if a coyote or other predators pulls on the baited M–44 unit. The chemical subsequently reacts with the moisture in the coyote’s mouth, releasing hydrogen cyanide gas. Death occurs extremely quickly (from 10 seconds to 2 minutes) after the device is triggered.
The M-44 is safe when property used and has minimal risk to the environment. The quantity of the toxicant in each capsule is approximately 0.03 ounce. If, due to some reason some of the contents of a capsule spill onto the soil, the active ingredient readily dissipates into gas due to soil moisture. If there is no moisture in the soil, the sodium cyanide filters into the soil and is readily degraded by micro-organisms or other possible mechanisms. Experiments conducted by WS' National Wildlife Research Center found that cyanide in contamination soil (from application of M–4) is very short lived. Cyanide decomposes quickly (within 24 hours) and is broken down into harmless byproducts.
It follows that bioaccumulation is extremely negligible due to the rate at which this material is metabolized immediately. Following the same reasoning, the risk of secondary poisoning where predators or carrion feeders consume a carcass of an M-44 poisoned animal is nonexistent. Secondary poisoning is defined as when one animal feeds on another that has been killed by a pesticide. In addition, the mode of action of cyanide also prohibits secondary poisoning. The mode of action of this chemical is asphyxiation which limits the assimilation of cyanide into the body of a poisoned animal. Simply put, an animal feeding on a coyote or other predator that has been killed by an M–44 will not be harmed due to the fact that there is virtually no poison in the dead animal’s tissues.
To protect the applicator against the event of exposure to the compound, however unlikely, amyl nitrite is available as an antidote. All M-44 applicators are required to carry an antidote kit .To prevent adverse or harmful effects to the environment, including nontarget animals, the potential impact of its activities must be evaluated before using the M–44 or any other wildlife damage management tool. In placing M–44's in the field, personnel use their expertise in animal behavior patterns to minimize the risk of attracting nontarget animals to the device. Through the use of specialized lures and attractants designed for offending animals, the risk to nontarget animals is highly minimized.
1080 Livestock Protection Collar. This is a tool when used properly selectively kills coyotes in the process of attacking sheep or goats. These collars are placed around the neck of sheep or goats that are pastured where coyotes are likely to or have attacked this prey. Each collar contains a small amount (300 mg) of Compound 1080 solution. The collars themselves do not attract coyotes, but, as discussed, are located around the throat of the potential prey. As a result, most attacking coyotes puncture the collar during their attack and consequently ingest a lethal amount of the toxicant. Unlike sodium cyanide, this toxicant is slow-acting, and any predator ingesting the toxicant does not exhibit symptoms for several hours and their prey (sheep or goats) are usually killed. The collar is registered only for use against coyotes and may be placed only on sheep or goats.
These collars are most effective when used in conjunction with specific goat and sheep husbandry practices. They function by killing coyotes or other predators that are in the process of attacking their prey. This may be accomplished by temporarily placing a “target” flock of perhaps 20 to 50 collared lambs or kids and their uncollared mothers in a pasture where coyote predation is likely to occur, while removing other sheep or goats from that vicinity. In situations where the collars have been used and found ineffective, the common cause of failure has been poor or ineffective targeting. It is difficult to ensure effective targeting if predation is occurring infrequently. In most instances, only a high and regular frequency of depredations will justify spending the time, effort, and money necessary to become trained and certified, purchase collars, and use them properly.
The main advantage of using this collar is that it selectively targets individual coyotes that are killing livestock. The device is one more tool in an integrated program towards predatory coyotes. Of course, there disadvantages with the use of these collars are namely, the prey (sheep) are typically killed in the process, the cost is relatively high ($20 each), and the additional problem of complying with governmental restrictions. The latter include requirements for applicator certification, training, and record keeping. One restriction limits use collars in fenced pastures only. As result, these collars cannot be used to protect livestock on open range. In addition, they are not widely available, because they are registered for use in only a few states. Their use has been greatly reduced in many countries including the U.S. due to the extreme toxicity of this chemical.
Fumigants. Gas cartridges are cylindrical devices contain 35% charcoal and 65% sodium nitrate and when ignited produce carbon monoxide, carbon dioxide, carbon, and other noxious gases. They have been registered with the EPA and are commonly used for control gophers, ground squirrels) and coyotes in dens. One drawback is that these devices are combustible and always presents the possibility of starting fires if not properly used.
Gas Cartridge. Image Courtesy Dr. Kaae.
Shooting. The U.S. government routinely shoots, poisons, traps, and kills 90,000 coyotes each year to protect livestock Shooting coyotes is legal in many situations, and is considered effective in removing a predator. Of course, safety is of first concern with shooting and its use may be limited by a few considerations, namely shooting is prohibited in many cities and if allowed may not be safe due to close neighbors. Again there are many aspects of shooting but most are beyond the scope of this document.
Conservation. Coyotes have long been one of the most controversial of all non-game animals. Agricultural interests have urged its control by whatever means necessary so that actual and potential livestock losses may be eliminated. Since 1891, when the first programs aimed at control were begun in California, nearly 500,000 coyotes have been reported destroyed at a cost of an estimated $30 million of the taxpayers' money.
Environmentalists are under the belief that the coyotes are necessary to preserve the balance of nature. This seems somewhat unrealistic considering a large population of the urban coyotes feed on dogs and cats. Sportsmen point towards the fact that the coyote is responsible for the declines of certain game animals. Biologists agree that individual animals preying on livestock and poultry should be destroyed but that the species as a whole is not necessarily harmful, because much of its diet is made up of destructive rodents. Biologists also agree that coyote populations have no lasting effects on other wildlife populations. Many pet owners in cities feel that these animals have no place in urban locations. So the controversy rages on.
True/False Tests for Credit.
Coyotes have recently been classified as non-game animals in California and othewr states and may be taken throughout the year under the authority of a hunting license.
50. Coyotes will typically bite the throat just behind the jaw and below the ear when attacking adult sheep or goats, with death commonly resulting “from suffocation”.
51. Due to the lack of harassment by residents, urban coyotes lose their natural fear of humans. This behavior is enhanced by humans intentionally feeding coyotes.
52. Urban coyotes may act aggressively toward humans, chasing bicyclists and joggers, stalking small children, and confronting people walking their dogs.
53. As with wolves, healthy coyotes typically target small children, mostly under the age of 10, though there are numerous instances of them biting adults.
Generally, donkeys are relatively docile with humans, but they appear to have an inborn dislike of dogs, foxes and coyotes. An often quoted advantage of the donkey as compared to guard dogsfor control of coyote damage is that donkeys readily eat the same food as sheep and they will also sleep with them at night
The U.S. government routinely shoots, poisons, traps, and kills 50,000 coyotes annually to protect livestock
The M-44 is safe when property used and has minimal risk to the environment. The quantity of the toxicant in each capsule is approximately 0.03 ounce. If, due to some reason some of the contents of a capsule spill onto the soil, the active ingredient readily dissipates into gas due to soil moisture. If there is no moisture in the soil, the sodium cyanide filters into the soil and is readily degraded by micro-organisms or other possible mechanisms
As with other jackrabbits, blacktails have characteristically long ears, and the long, powerful rear legs. They reach a length of about 2 feet, and a weight from 3 to 6 pounds. This is the third largest North American hare, second only to the antelope jackrabbit and the white-tailed jackrabbit. The blacktailed's dorsal fur is dark buff (peppered with black) with creamy white undersides and insides of its legs. The ears are black-tipped on the outer surface, and unpigmented inside. The ventral surface of the tail is grey to white, and the black dorsal surface of the tail continues up the spine for a few inches to form a short, black stripe.
Black-tailed Jackrabbit. Image courtesy Jim Harper.CC BY SA 2.5
Biology and Distribution. These rabbits normally prefer open to semi-open habitats of foothills and valleys. They are rarely found in woodlands or dense brush. Within these locations, they are adaptable and inhabit areas around the fringes of suburban and urban developments such as golf courses, green belts, parks, agricultural situations and airports. These hares may be seen during the day but they are primarily crepuscular and nocturnal. Jackrabbits feed on a variety of plants including sagebrush, cactus, mesquite, berries, juniper , grasses, and a variety of crops including alfalfa and clover. These pests do not exhibit major daily movements in search of food. If food and shelter are separated, they will move between these areas in the evening and morning. Daily travels of one to two miles between such locations are quite common. During drought or dry periods, roundtrips of up to 10 miles have been observed. In doing so, they travel the same trails every day producing noticeable paths.
Jackrabbits and other hares drink very little, thus obtaining the majority of their water from food. Jackrabbits and other hares do not use burrows, but rest during the day in a shallow scrape, called a "form," dug into the soil. Such locations are typically covered or surrounded with vegetation.
These rabbits rely on their well-developed sense of hearing, speed, and agility to escape from potential predators. Jack rabbits can run up to 40–45 miles per hour and can leap 19 feet-in a single bound-super rabbit. Even though these rabbits are typically solitary critters, they frequently rest and forage in groups. This provides a distinctive advantage with each individual relying on the senses of the others to detect predators. As with many hares, they will thump the ground with their hind legs thus functioning as an alarm of potential danger.
In southern regions, breeding can occur year-round. In the wild, females rarely if ever breed prior one year of age even though they are fertile earlier. A healthy female is capable of producing four to five litters annually with one to eight young per litter. In the wild, young typically weigh an average of 3 oz. at birth with captive borne significantly larger. Birth typically occurs in the spring and in a form or close to dense brush. If multiple young are produced in a litter, the female typically does not leave them in a single location. Logically, this would function to prevent a predator from killing the whole litter. Gestation is relatively long (lasts 45 days), and resultantly the young are relatively independent from birth; However, the mother nurses the young for a full 12 weeks.
As with many hares, these critters may undergo "population booms" and cycles, which are frequently localized: as a result, their numbers may be plentiful in one valley while almost absent from adjacent areas. Population crashes are often a result of disease (commonly Tularemia). Other factors including food availability can also influence a local population level. Of course with such population booms or bust, it would follow that mammalian (especially coyotes) and avian predator could follow suit. Since these critters have a high reproduce capacity, their population usually recovers quickly after a crash, provided suitable environmental conditions exist.
As with other cottontails, this species possesses a rounded tail covered by white fur on the underside which is characteristic and very visible as a rabbit retreat. Their fur is light grayish-brown with a nearly white belly. Adults average 15 inches in length and weigh up to slightly over three pounds. Their ears average 31/2 inches in length, and their hind feet are quite large, almost 3 inches long.
Desert cottontail. Image courtesy How Cheng. CC BY-SA 3.0
There is minimal sexual dimorphism, but females are typically larger than the males, and exhibit a smaller home range of approximately 1 acre compared to 2 acres for a male. This species is not typically active at mid-day, but it can be seen in the early morning or late afternoon. It mainly eats grass, but will eat many other plants, even cacti. It rarely needs to drink getting its water mostly from the plants it eats or from dew. Like most lagomorphs, this species is corprophagic- meaning reingesting and chewing its own feces, thus allowing more nutrition to be extracted. Many desert animals prey on cottontails including birds of prey, coyotes, bobcats and humans. The cottontail's normal anti-predator behavior is run away in zig-zags; it can reach speeds of over 19 mph. With small predators it defends itself by kicking. The young are born in a shallow burrow or above ground, but are helpless when born, and do not leave the nest until they are 3 weeks old. Where climate and food supply permit, females can produce several litters a year. Unlike the European rabbit, they do not form social burrow systems, but compared with some others, they are relatively tolerant of other individuals in their vicinity.
Unlike jackrabbits, desert cottontails typically are found in habitats with dense cover such as wooded areas with minimal underbrush, brushy areas, or locations with piles of debris or rocks. In addition, agricultural fields or unused structures are also commonly used for cover. Open locations are typically used at night while dense cover during the day. These rabbit rarely feed more than a few feet from cover. Cottontails and brush rabbits are not territorial but maintain home ranges of up to 10 to 15 acres that overlap broadly with other individuals of all age and sex. These rabbits do not have the same degree of daily travel as indicated by jackrabbits; however, they use distinct travel lanes within their home range.
The breeding season of cottontails typically begins in December and ends in June depending on location. Annually, they average from 3 to 4 litters, but 6 litters are not unusual. Newborns are nearly furless and with closed eyes and remain in the nest for a few months. The feeding habits of these pests depend on time of year and location. Prime diet consists of consists of sedges, herbaceous plants, wild rose grasses, willows, and blackberries. On the other hand, brush rabbits feed on the stems and berries of woody plants such as blackberry, clover, and alfalfa is available.
This cottontail occurs in western coastal regions of North America from the Columbia River to the southern tip of the Baja California and extends as far east as the eastern sides of the Sierra Nevada and Cascade mountains.
Brush Rabbit. Image Courtesy Walter Siegmund. GNU Free Documentation License. CC BY-SA 2.5
This species is smaller than most cottontails, and unlike most, the underside of the tail is grey as opposed to white (which may be why its common name does not include the word "cottontail"). The dorsum of this specie's fur varies from light brown to grey while the venter is typically white in coloration. Adults vary from 10 to14 inches in length and rarely weigh more than two pounds.
Biology and Distribution. Unlike jackrabbits, this species is typically found in habitats with dense cover such as wooded areas with a minimum of underbrush, brushy areas, or locations with piles of debris or rocks. In addition, they are found in cultivated fields or where abandoned structures are used for cover. Open locations are typically used at night, while dense cover during the day. This rabbit rarely feeds more than a few feet from its cover. Brush rabbits are not territorial but maintain home ranges of up to 10 to 15 acres that overlap broadly with other individuals of all age and sex. These rabbits do not have the same degree of daily travel as indicated in jackrabbits, although they use of distinct travel lanes within their home range.
Brush Rabbit mating typically occurs between February and August but may be year-round depending on conditions and environment. The female gestation period of this species is approximately 22 days. A female is capable of producing up to five litters annually, but two to three is more typical. Each litter contains 1 to 7 young which are helpless. Their home range consists of a series of paths that connect high use habitats. Multiple rabbits commonly simultaneously feed in the same area, but maintained an inter-individual distances of one to 24 feet prior the occurrence of aggressive displays and chases. It is thought, but not documented, that grouping of brush rabbits may function as survival purposes of predator detection. This species mainly feeds on forbes and grasses, especially clover, though it will also fed on berries and browse from bushes. Its predators include bobcats, coyotes, cougars, foxes, snakes, and various raptors. This species is not hunted as commonly as are other cottontail species, probably because of its relatively small size. It is not a major pest. Certain subspecies of the brush rabbit are considered endangered and are protected by state and federal laws.
Legal Status. Jackrabbits, cottontails, and brush rabbits are classified as game mammals by the California Fish and Game Code; however, there is an important distinction between the three species as far as control. Jackrabbits may be controlled (i.e., killed or trapped) anytime or in any legal manner by the owner or tenant of the premises, or employees thereof, if they are damaging growing crops or other property, which includes ornamental plants and irrigation lines. Cottontails or brush rabbits may be killed or trapped by the owner or tenant of the land, or by any person authorized in writing by such owner or tenant, when the rabbits are damaging crops or forage. If any person other than the owner or tenant transports cottontails or brush rabbits from the property where they were taken, they must carry written authority from the owner or tenant. These rabbits cannot be sold. Wildlife enforcement officers may not allow killing or trapping of cottontails or brush rabbits when the damage they are causing is to ornamental plantings or to property; contact your local game warden for information. The omnivorous feeding habits of rabbits is well-illustrated by the following partial list of crops and plants they attack: vegetables (carrots, beans, beets lettuce, broccoli, peas): tree and berry crops (citrus, blackberries almonds, apples cherries, pistachios, strawberries, plums, raspberries); herbs (cilantro, parsley: ornamentals (various flowers, shrubs, turf and trees). These pests also gnaw and cut plastic irrigation lines.
Damage. The majority of damage is close to the ground. An exception would be where snow is present thus allowing them to feed higher up on plants. Their damage on plants is characterized by a 45 degree cuts when clipping off buds, twigs, or flower heads. Twig clipping from these pests may be confused with browsing from deer. Obviously deer damage occurs above a height where a rabbit cannot reach (about two feet). In addition, deer lack upper front teeth and as a result must twist and pull down when feeding thus leaving a ragged break on the branch. As indicated, rabbits clip twigs off cleanly, as if with a knife.
These pests normally gnaw smooth bark from young trees as opposed to the rougher bark of old trees. Old damage and gnaw marks are often present on old bark along with fresh patches of gnawing in areas of younger growth. Excessive gnawing can completely girdle a tree and eventually killing younger trees. Clipping will eventually prohibit the development of terminal shoot and lateral branches. Damage by cottontails and brush rabbits is frequently found and often limited to locations near escape cover. On the other hand, jackrabbits feed far into open areas.
Control. Fencing. One of the most long-term, effective means to protect vegetation from damage due to these pests is to build a fence. Fencing should be at least 48-inch-tall as jackrabbits and other species are quite agile and can jump over shorter fences. In the case of wire fences, the bottom should be buried at least six inches. In addition, bending the bottom a few inches outwardly will decrease the possibility of rabbits from digging under it. An alternative to this is to stake down the bottom edge. Mesh size should be 1 inch or less. Fences should be inspected regularly to insure these creatures or other animals have not dug under them. Poultry wire with light stakes is adequate for rabbit control.
Electric netting (a type of electric fence) is commercially available and effective for control of these pests. This type of fencing is constructed for ease of installation and can readily be repositioned. This type of netting is normally intended for temporary use, thus making it ideal for seasonal gardens. Due to the variables affecting the selection and operation these types of fence, it is best to consult a reputable dealer for specific details regarding its use.
Trunk Guards in certain situations, protecting plants is more practical than excluding these pests from a given location. Chicken wire (poultry netting) 18 to 24 inches wide, can be cut into sections and formed into cylinders that can be used to protect trunks of shrubs, vines or young trees. The bottoms of the cylinders should be buried two to three inches in the soil and placed away from the trunk. These cylinders should be inspected regularly. Commercial tree trunk protectors ar. e available.
Commercial tree trunk guard.
Trapping. Live trapping of cottontails and brush rabbits is not recommended because it creates the problem of what to do with the trapped animal. Rabbits can carry certain diseases (especially tularemia). Although this disease is somewhat uncommon, handling a dead or alive wild rabbit can be of concern to the trapper. In addition, since they are considered agricultural pests according to California Fish and Game Code, it is illegal to release them in new areas without a written. permit.
These can be trapped with a Conibear trap (No. 110). Of course this presents the same problem of disposing of the dead animal and the possibility of exposure to tularemia. In the interest of safety, these traps should be contained inside a covered sturdy plywood box with a four-inch-wide entrance. The trap should be positioned as far away as possible from the entrance. Other kill-type traps are also commercially available.
Conibear trap #110
The trap should be placed close to the feeding or resting location of the intended rabbit. Common baits include cabbage, carrots, apples, fresh green vegetables, or whatever the rabbits are currently feeding on. The bait should be placed at the back of the trap. It may be of use to place a small amount of bait outside the trap and check it regularly.
Repellents.The usefulness of repellents is limited and in many conditions is not that effective. The use of these chemicals usually fails when used in vegetable gardens that contain highly preferred rabbit foods.
Harborage. Harborage or habitat removal will discourage these pests, especially in urban locations where alternate suitable habitats are at a minimum. Remove piles of brush and wood, brambles, stones, or other debris where these pests can hide. Vegetation near ditchbanks, along fence rows, or brushy areas can be removed. It should be noted that this will have little if any effect on jackrabbits due their ability to travel considerable distance in search of food.
Shooting can be of value with small numbers of rabbits in rural location where it is legal. Since rabbits are most active in the morning and dusk, best results are typically achieved at these times. Since these are considered game animals, license requirements and any restrictions on shooting should be checked.
Ultrasonic devices and other frightening devices such as noisemakers and flashing lights are generally not effective.
True False Questions for Credit.
There are a variety of poisoned baits that are registered for jackrabbit control when serious crop damage occurs in agricultural situations. Their use in suburban and urban location is not practical or recommended; because the rabbits are likely to die outside the baited property, carcass recovery, which is required in almost all situations, is almost impossible.
Ultrasonic devices and other frightening devices such as noisemakers and flashing lights are generally not effective.
Unlike jackrabbits, desert cottontails typically are found in habitats with dense cover such as wooded areas with minimal underbrush, brushy areas, or locations with piles of debris or rocks. In addition, agricultural fields or unused structures are also commonly used for cover. Open locations are typically used at night while dense cover during the day.
43. Muskrat fur has 2 layers, which helps protect them from the “cold water”.
Jack rabbits can run up to 40 to 45 miles per hour and can leap 99 feet-in a single bound-super rabbit.
46. During dry periods, Jack rabbits will travel “roundtrips” between food and shelter of up to 10 miles. Jack rabbits can run up to 40–45 miles per hour and can leap 19 feet-in a single bound-super rabbit.
47. Damage by cottontails and brush rabbits is often concentrated in areas near “escape cover” while jackrabbits, however, will feed far into open areas and can eat 1/2 to 1 pound of green vegetation each day.
Big-eared bat. Image courtesy of Dave Bunnell / Under Earth Images CC BY-SA 2.5
Many people needlessly fear bats. This points out the need to educate the public on the importance of bat conservation and why it is important to use non-destructive methods to eliminate or reduce conflicts between humans and bats. Valuable sources of information on these creatures include various states Cooperative Extension Services, government environmental conservation agencies, universities, health departments, and Bat Conservation International. Except where control is mandated, these mammals should be appreciated — and not disturbed. It is well-documented that bats serve important functions in various ecosystems including control of a number of insect pest species. Bats, the only mammals that truly fly, belong to the order Chiroptera. Their ability to fly, their secretiveness, and their nocturnal habits have contributed to bat folklore, superstition, and fear. They are worldwide in distribution and include about 900 species, second in number only to the rodents among the mammals.
Bats are one of the most common and variable groups of mammals and are found on all continents with the exception of Antarctica. This order represents over 50 million years of adaptation to many different environmental conditions and truly unique niches. Since they are the only true flying mammals, they are amazing for a number of reasons including the ways their bodies have evolved for flight. Through the processes of evolution, their front legs evolved into wings and their hips rotated 180 degrees, allowing them to hang by their feet. Bats also developed the behavior of echolocation, or utilize sound to help locate objects (including food) and orient and navigate through caves and forests. There are over 1,000 species of these mammals and much function as an essential role in their environment— including consuming vast quantities of insects. In addition, they redistribute nutrients throughout the forest via guano. Many species are essential pollinators and dispersers of various seed from the fruit they consume.
Although quite common in the U.S. prior to 1900, 13% of bat species are now at risk of extinction due to human disturbance. Among the 40 species of bats found in the U.S., only a few species occasionally cause problems for humans. It is worthwhile to note that the vampire bat does not occur in the U.S. The colonial species (those living in groups) most often encountered in and around human buildings in the U. S. are the big brown bat, pallid bat, little brown bat, the Mexican free-tailed bat, evening bat, and Yuma myotist. Solitary bats mainly roost in trees or under bark, but on occasion may be found in and around buildings.
Bats inhabiting structures are capable producing offensive odors and unsettling sounds and may carry rabies. Besides biting bats are capable of transmitting this disease via a few means; there is evidence that exposure of cut or abraded skin, bat urine, or even the mere inhalation of cave air may be infective. Since there are no bloodsucking bats in the U. S., a bat bite is unlikely to occur unless someone is handling or otherwise disturbing these creatures. Brown bats are known to be reservoirs of encephalitis which can cause death and mental retardation. Histoplasmosis, a fungus disease, may be contracted by humans due to inhalation of dusty bat manure containing spores of the fungus.
The big brown bat and California myotis bat are distribute throughout California except in the high mountain zones. The other 22 bats found in this state are found in various parts, with considerable overlap of distribution. The silver haired bat, red bat and hoary bat migrate to the coast in winter, but other species are permanent residents.
All of these bats are nocturnal and roost in tree foliage, caves, crevices, tunnels, or structures during the day. Depending on the species, some may have a separate night roosting location in order to retire between feeding flights. Certain bats are more particular about the kind of roost they use. Many hibernate in caves in winter, and may relocate from cave to cave. The more stationary species typically inhabit the same roost throughout the year and year after year.
The size of bats is quite variable with the smallest mammals being the bumblebee bat of Thailand (smaller than a grape), while certain of the fruit bats (“flying foxes”) found in the tropics of Asia (also including Thailand) can possess a wingspan of up to 6 feet. As might be expected, their shapes vary and this typically corresponds to food type and highly specialized hunting or foraging habits. For example, some insectivorous bats that feed over water have adaptive large ears, wing and feet when compared to insectivorous bats that catch insects in mid-air. Over 70% of bats feed on insects while most of the remainder is tropical species that feed on nectar and fruit. A few are carnivorous eating birds, frogs and birds.
It is commonly known that bats rely on echo-location in order to avoid collisions and to determine location of prey. The majority of these creatures feed almost totally on insect that they catch on the fly. There are 2 California species that are herbivorous feeding solely nectar, fruit and pollen. Bats hang upside down when resting since their legs and wings not well-developed enough to help launch themselves when preparing to fly. Many species of bats conserve energy during the day and when hibernating by lowering body temperature (and hence metabolism) close to that of their environment.
Little is known about reproductive behavior in bats. Breeding typically occurs in autumn prior to hibernation, or during winter roost, of course depending on the species. Ovulation occurs after winter when hibernation is over and their eggs are subsequently fertilized by stored sperm. The single young (possibly two but with a few species up to four) is born two to three months later in late spring to early summer. Newborns are hairless and typically cling to the female for some time after birth; no nest is ever built. In many species the adults separate subsequent to giving birth with each males living alone through the summer while the females remaining together. Most species are colonial with a few solitary. Bats have relatively few enemies (snakes and owls) and depending on species live to 20 years or more.
Bats are classified as nongame mammals by California Fish and Game Code. Nongame mammals which are detriments to crops or other property may be taken by the owner or tenant of the premises, except is leg-hold steel-jawed traps are used they shall not have saw-toothed or spiked jaws or have a spread of 5 ½ inches or larger without offset jaws. They may also be taken by officers or employees of the California Department of Food and Agriculture or by federal or county officers or employees when acting in their official capacities pursuant to the provision of the Food and Agricultural Code pertaining to pests.
Little Brown Bat (Myotis lucifugus)
This bat is pale tan through reddish brown to dark brown, depending on geographic location. The species is a rich dark brown in the eastern U.S. and most of the West Coast. Fur is glossy and sleek.
Little brown bat. Image courtesy of U. S Fish and Wildlife Services. Public Domain.
This is one of the most common species that inhabit structures, and is frequently located near lakes, ponds, and other bodies of water where they forage for insect. Summer time colonies are extremely gregarious, commonly roosting in hot, dark, attics and are frequently found in roof spaces where colonies may include hundreds to thousands of bats. These colonies may be found beneath bridges, siding and shingles, in tree hollows, and caves. Litter size varies depending on geological location with a single young in the Northeast and occasionally with twins in certain other areas. Males tend to be located in separate areas and occur in smaller in numbers and choose cooler roosts behind shutters, under tree bark, within attics, within caves, and in rock crevices.
As colder winter temperatures come in the eastern U.S., the little brown bats abandon buildings and other structures and head for mines and caves to hibernate in. Such locations may range from up to a few hundred miles away from their summer range. In the western U.S., very little is known of the winter habits of this species. These bats have a relative long live span with reportedly one individual surviving 31 years, although the norm is closer to a few years.
Big Brown Bat (Eptesicus fuscus)
As with many bats, the coloration of this species varies from dark brown to cooper to reddish brown, again depending on geographic location. This large, hardy, sedentary bat lacks distinctive markings and commonly roosts in structures. Summer maternal colonies may range from a dozen or so to hundreds. Common roosting locations include in barns, attics, hollow walls, chimneys, enclosed eaves, attics, and behind unused sliding doors and shutters. Outdoors they also form colonies in hollow trees, rock crevices, under loose bark and beneath bridges. Litter size is 1 or 2 depending on geographical location
This species has one of the widest distribution of U.S. bats and is a more commonly recognizable species due to its large size and behavior of commonly overwintering in buildings (e.g. wall spaces, attics, basements). This close association with humans, combined with its behavior of moving about as temperatures shift, frequently brings this species into human living quarters and basements in both the summer and winter. This species also hibernates but its winter quarter are largely unknown but more than likely include burial vaults, mines, caves, storm sewers, and other underground locations.
Mexican Free-Tailed Bat (Tadarida brasiliensis)
This species is dark gray or dark brown with the fur of some individuals having it bleached to a pale brown as a result of exposure to amonia fumes from urine and decomposing guano. As a result, this species is quite distinctive when compared to other building inhabiting species.
Mexican free-tailed bat. Image courtesy of NPS. Public Domain.
This species forms the largest colonies of any warm-blooded animal in the U.S. and most of the world. Colonies of this species may be extremely large and range from a few hundred to several thousand individuals and may be found in structures and under bridges, particularly in the West Coast and Gulf States from Texas east. It is mainly a cave bat in the south including Texas, Oklahoma, New Mexico and Arizona; in these states buildings are used as temporary roosts during migrations. The Mexican free-tailed bat frequently shares building roosts with other species including the big brown and pallid bat. A few males can be observed in large maternity colonies, but they generally occur in separate caves.
Pallid Bat (Antrozous pallidus)
This species is 2½ to 3 inches long and has 1½ to 21/4 inch long tail. It weighs ½ to 11/16 ounces. Its nose is, for lack of a better term, pig-like in appearance. Its wooly fur is typically paler than many other species. It bears facial glands that produce a skunk-like odor which likely function as defense.
The distribution of this species stretches from Mexico to western North America including Cuba. It is mostly found in dry habitats including scrubby deserts to grasslands including Death Valley in California, one of the least inhabitable deserts of extreme heat.
Colonies of the pallid bat nocturnally roosts together in attics, trees and rocky outcrops. They communicated to each other with piercing directive cries in order to locate their roost. Maternity colony size ranges from about 12 to 100 individuals. Roost sites include buildings, bridges, and rock crevices and less frequently tree cavities, caves, and mines. Litter size is most commonly 2. Their roosts are frequently shared with T. brasiliensis and E. fuscus in the West. While groups of males tend to segregate during the nursery period (sometimes in the same building), other males are found within maternity colony.
This species flies close to the ground, may hover, and catches most of its prey on the ground or on tree-quite unusual for bats. Its diet consists of scorpions, beetles, grasshoppers and crickets, all mainly ground dwellers. This species is well-known for its long migrations although little is documented as to it winter habits.
Breeding starts in October and last until the end of winter. Gestation ranges from lasts 53 to 71 days with a subsequent litter of one or two young. The young begin flying at four to five weeks and are weaned at six to eight weeks. Both males and females reach sexual maturity in less than a year and breed during their first breeding season. As with many bats, they are long lived and in the wild survive up to 9 years.
California Motes Bat
The distribution of this species ranges from Southern Alaska and southward to most of Mexico. It is one of the smallest bats in the U. S. occupying a variety of habitats in the Pacific Northwest and southern and western British Columbia from the humid coastal forests to semi-deserts, and from sea level to at least 5,940 feet elevation. In arid regions, it usually occurs in the vicinity of water. Individuals emerge shortly after sunset to forage, which continues at irregular intervals until dawn.
This species exhibits erratic, slow flight and hunts mainly around the edge of trees, over water, and well above ground in open situations. These bats roost in buildings, under loose bark, in rock crevices and hollow trees. During the summer the females form small maternal colonies with the males roosting separately, but both sexes are found together from fall to late winter. California bats hibernate in mines and caves. The species is insectivorous feed primarily on beetles, moths and small flies. It locates and feeds in concentrations of insects such as mating masses of mosquitoes and midges. It is very agile and rapidly maneuvers in flight in order to capture multiple prey over a short distance.
General Bat Biology and Feeding Habits
Almost all North America bats are insectivorous and feed on a variety of flying insects such as mosquitoes. Insectivorous bats apparently consume a wide range of prey including beetles, moths, flying ants, true bugs, caddis flies, mosquitoes, midges and mayflies to name a few. They can consume insects equal to a third of their total body weight in a half-hour. It would follow that the nightly consumption of insects by a large colony of bats would be astronomical.
Generally speaking, bats mate in the fall and winter, but the female stores the sperm until spring, when ovulation and fertilization subsequently occurs. Pregnant females may congregate in maternal colonies in mines, caves, hollow trees, beneath bridges and buildings, behind chimneys, and other dark retreats. Birth typically occurs from spring into summer with young bats capable of flying within three weeks. Weaning occurs in a month or so, after which colonies disperse
Some species migrate short distances in preparation for winter; other such as the Mexican free-tailed bat may migrate up to 1,000 miles. Bats in the northern U.S. may hibernate from late fall to spring with the same species in the south exhibiting shorter or sporadic hibernations. Bats are long lived with some species surviving in the wild 10 years or more.
Due to human encroachment (indirect or direct), a number of species of bats species in the U. S. have declined in number. Pesticides (particularly the use of bio-accumulation of organic pesticides and persistent insecticides) kill much of their natural food (insects), and contaminated insects ingested by bats have drastically effected their populations. In addition significant numbers of bat are killed when summer maternal roosts and winter hibernacula are disturbed by human activity. Vandals, other irresponsible individuals and even speleologists or biologists may unintentionally disturb hibernating bats, resultantly in depletion of fat reserves that are required for hibernation.
Sealing and flooding of caves and mineshafts and general quarry mining may inadvertently destroy bat harborages. Forestry practices ultimately destroy hollow trees.
Bats use a variety of roosting locations including livestock quarters, attics, outhouses, warehouses, loading docks, foyers, highway under passes, wells, grave cypts, carports, under barks of trees, bridges, highway, pavilions, carports sighs, and windows shutters. Once established in such areas, a number of problems can develops including health issues, public annoyance, aesthetic problems, and much more. Consequently, pest management may be needed. The initial step once the presence of these pests is established is species determination. Common symptoms of the presence of these critters are discussed below.
Surfaces close to bat entryways such as walls, between bricks, under loose woodwork characteristically develop a sticky, polished, somewhat smooth appearance. These areas may also contain scattered bat hairs, and may take on varied coloration ranging from yellow-brown to black-brown. This is typically caused by bats coming and going through these areas and rubbing body oils, and other gland secretions which are subsequently mixed with dust.
The presence of bats in a structure often result in a number of sounds due to their crawling or climbing in attics or other areas, vocalizations, grooming, and scratching. These creatures are frequently very noisy prior to leaving the roost at dusk, on hot days in attics, and upon returning to their roosts. It is worthwhile noting that noises in chimneys may be caused by birds or raccoons and scratching, running and thumping sounds in attics and behind walls may indicate the presence of squirrels, raccoons, opossums, mice or rats.
Guano and Urine
Fecal pellets are used to determine the presences of a variety of animals (rats, mice, coyotes, various game, birds, insects). Feces outside and inside walls may indicate the presence of mice, rats, roaches, termites and even wood boring beetles. Since the majority of home infesting bats north of Mexico are insectivorous, it is important to distinguish their feces from that of other pests, especially small rodents. Bat droppings are typically friable, segmented, and elongated. When crushed, they are powdery and reveal shiny bits (exoskeletons) of undigested insect remains. In contrast, mice and rat droppings tend to taper at their ends, are unsegmented and harder and when crushed are not powdery nor do they contain insect parts. Lizard and bird feces could possibly be confused with that of bats but can readily be distinguished by the lack of white chalky material (calcium) in their feces.
Large quantities of bat guano produce an unpleasant odor. This pungent, musty, acrid smell can even be detected from outside a building that contains a well-establish large colony of these critters. Odor problems also occur when animals die (rats, bats, mice) in wall voids and other inaccessible locations. In addition, the presence of these dead animals attracts a variety of insect pests (maggots, carpet beetles and others). Microorganisms also grow on dead animals including those (fungi) that cause human histoplasmosis. With heavy infestations (large colonies over time) guano may accumulate and fill spaces between floors and, ceilings, possibly creating multiple safety hazards including weakening ceilings to the point of collapse. Such quantities of guano can result in staining of many materials.
These pests urinate and defecate in flight which can result in staining and multiple spotting on cars, patio furniture, windows, buildings and other objects in the vicinity of entry/exit holes or under roosts. Bat excrement are contaminates of a variety of commercial products, stored foods, and other surfaces.
Bat urine crystallizes when warm often forming large accumulations. Beams and lumber become saturated with urine and ultimately are coated with whitish coating of crystals. With large colonies, thick and hard stalactites and stalagmites of crystallized bat urine are occasionally formed. When exposed to bat urine over an extended period, wood deteriorates. In doing so wood fibers ultimately separate and expand. These fibers are ultimately torn loose as a result of bats crawling over these surfaces, resulting in wood fibers mixed with guano.
The close proximity of humans and bats can result in exposure to a variety of unhealthy material including microorganisms, fragments of arthropods, animal dander, and excreta (guano and feces). These materials may enter air ducts or merely fall onto the occupants below. The result is of course exposure to airborne particles of public health significance.
This system relies on ultrasonic sounds that are emitted specifically to produce echoes. The bat compares the outgoing pulse with the returning echoes. In doing so, it can produce detailed images of its surroundings. This allows it to detect, localize and even classify their prey in complete darkness.
Two families of moths (Noctuidae-underwings and Arctiidae-tiger moths) exploit the bats echolocation to avoid being caught and eaten. Tiger moths are notoriously foul tasting due to chemicals in their body. Being so, they are brightly colored. Brightly colored animals, including insects, normally are so to warn predators to avoid them as they have well- adapted defensive mechanism. Since bright colors are not easy at sees at night, bats initially eat a few but learn not to eat them due their foul taste. However, why do bats learn avoid theses moths as they are dependent on echolocation to find their prey? The answer is that tiger moths on sensing the echolocation of a hunting bat, produces its own ultrasonic signals to warn the bats that they (the moths) are chemically protected. The Noctuid moths can also detect ultrasonic echolocation sounds from hunting bats. However, in this case the moth merely reacts by erratic, evasive flight and in many cases falls to the ground, thus avoiding the bats.
Bat Exclusion and Removal. Bats access buildings via openings such as siding, eaves, dormers, roof vents, chimney vents, apex of gables associated with the roof edge and valleys, opening under loose-fitting doors, gaps around various conduits (wiring, plumbing, air conditioning) that pass through walls, and through utility vents. Bats are capable of squeezing through cracks and slits. As a result gaps of approximately 1/4 x 11/2 inches or any hole that measures 5/8 x 7/8 inch should be considered possible entry points, Openings of this size are common in older wood frame houses and structures using lumber that have warped, shrunk, or otherwise modified.
The discovery of a few of these creatures in a home is a common problem. In northeastern U.S, big brown bats more than likely account for sudden appearances of these creatures in structures since in urban areas, they often enter homes through unscreened fireplaces and open windows. If unused chimneys contain summer roosts, sooner or later bats will crawl or fall through an open damper. It is not that unusual for one of these creatures to suddenly appear in a room, and then just as quickly disappear by crawling under a door to another location or area in the home including other rooms, behind curtains, into waste paper baskets, under beds, bookcases, and wall hangings, to name a few. As a result, locating and removing individual bats once their presence is known can be time consuming and sometimes difficult. If all fails, the bat will sooner or later reappear once as it attempts to find an exit. Since big brown bats normally hibernate in the cooler areas of heated buildings, they may appear (flying outdoors or indoors) in midwinter during a cold snap or warm spell as they are activated due the temperature shift.
48. Porcupines are nocturnal animals and active all year; however, much time is spent resting in trees “called “rest trees”.
49. The best baits for porcupine traps are “strips of plywood” or other absorbent woods, cloths, or sponges soaked in salt water.
The guard hairs of a porcupine function to protect them from rain and snow. They are also tactile in nature allowing these pests to feel the surrounding environment.
Excessive killing and trapping of natural predators, such as coyotes, mountain lions and fishers, could increase porcupine numbers. As a consequence, fishers have been released in several states including Oregon, California, Montana, Idaho, Vermont, Wisconsin, and New York. These releases were not done in order to control porcupine populations specifically; however, Michigan researchers indicated these fishers appeared to decrease porcupine numbers.
50. Coyotes will typically bite the throat just behind the jaw and below the ear when attacking adult sheep or goats, with death commonly resulting “from suffocation”.
51. Due to the lack of harassment by residents, urban coyotes lose their natural fear of humans. This behavior is enhanced by humans intentionally feeding coyotes.
52. Urban coyotes may act aggressively toward humans, chasing bicyclists and joggers, stalking small children, and confronting people walking their dogs.
53. As with wolves, healthy coyotes typically target small children, mostly under the age of 10, though there are numerous instances of them biting adults.
54. Rabies virus is transmitted through saliva and brain/nervous system tissue. Only these specific bodily excretions and tissues transmit rabies virus.
55. A recent study of 145 ranches where “guard llamas were used” to protect sheep revealed that average losses of sheep to predators decreased from 26 to 8 per year after llamas were employed.
56. The USDA estimates that total deer damage from “auto collisions” and crop and timber losses reaches at least $3 billion a year
57. Bats rely on reflection of “high-pitched squeaks” they emit to avoid collisions and to determine location of prey.
58. Contact such as petting or handling an animal, or “contact with blood, urine or feces” does not constitute an exposure to rabies.