Category Archives: Mammals

Mammals, Wildlife

Fisher – Martes Pennanti

Fisher

Martes Pennanti

General

The fisher (Martes pennanti,) is a medium sized member of the weasel family (Mustelidae,) native only to North America.  They are striking with their slender bodies and soft dark coats but are increasingly becoming a problem in certain geographic zones where populations are expanding into suburban areas.

Description

Male fishers tend to be larger than females, reaching a mature length of 50” to 63” and mature weight of 7.5 lbs. to 11 lbs. by one year old.  Females measure 41” to 51” and weigh between 4.5 lbs. and 5.5 lbs. by 5.5 months old.  Their long, thick, bushy tails account for approximately 1/3 their total length.  Fishers have long bodies, broad heads with short pointed muzzles, and short legs.  Round ears are located on the sides on the head.  They have five long, retractable claws on both their front and hind feet.

Fishers have soft coats that are medium to dark brown and frosted on the head, neck, and shoulders.  Their coats are accented by black on the legs and tail and white patches (that may occur on the chest, genital area, and underarms.)  Their coloration may vary due to sex and season (they tend to be darker in the winter.)

Fishers are solitary animals that are active during the day and night.  Although they spend much of their time alone, they may be found together during the mating season.  Male fishers are known to show aggression towards each other.  Fishers are shy around humans but are beginning to show more and more comfort near human populations as their ranges expand in certain geographic areas.

Fishers create dens and “resting sites”1 for year-round use in hollow logs, trees, brush, ground burrows, or crevices.  They show preference for tree nests in the spring and fall, while in the winter they tend to use ground burrows or snow dens (burrows in the snow accessed by long, narrow tunnels.)

Fishers establish home ranges that are 5.8 to 13.5 square miles in size.  Males’ ranges are typically larger than females’ ranges and tend to overlap with them; however, a male’s range will never overlap with that of another male.2  Fishers mark their territory using scent and travel within it using established trails on the ground and in the trees.3  They navigate their environments using keen senses of smell, sight, and hearing.  Although they are agile climbers and swimmers, fishers are usually found on the ground.

In the wild, fishers can live up to 10 years.

Habitat

Fishers may be found in mixed, coniferous, and deciduous forests.  They prefer habitats that offer den sites (including hollow trees,) access to prey, and high canopy enclosures.  They tend to avoid deep snow in the winter.

Within their habitats, juvenile fishers are at risk of predation by hawks and other birds of prey, bobcats, lynx, and red foxes.

Location

Fisher populations can be found across Canada and the United States (from the Sierra Nevada in California to the Appalachian Mountains in Virginia.)  They no not live in prairie habitats or the southern United States.  North America is the only continent on which fisher populations occur.

Diet

Fishers are solitary hunters whose diets consist mainly of small herbivores (such as rodents, birds, and shrews.)  Their diets may also include fruit, berries, and carrion.  Although they usually prey on animals smaller than themselves, fishers have been known to take on larger prey.  They are also one of the only predators that can effectively attack a porcupine (this is done by repeatedly attacking from the front until the porcupine tires, then flipping it on its back and attacking its unprotected stomach.)

Fishers are agile hunters in trees and are capable of elongating their bodies to hunt their prey in ground burrows and narrow spaces.

Reproduction

Fishers breed once a year between March and May.  Copulation lasts for several hours.  Once the embryos have been fertilized, they remain in a suspended state of development for the first 10 to 11 months of an 11 to 12 month gestation period.  Embryos only develop during the last 1 to 2 months of gestation.

Females choose den sites that are high off the ground in hollow trees.  The site of the den may be moved several times if the nest is disturbed.

Litters contain 1 to 6 young (on average 3,) that are born blind and naked, each weighing less than one-tenth of a pound.  The young, known as kits, are completely dependent on their mothers after birth (males provide no parental support.)  Their eyes open around 7 weeks old, and they are weaned by 8 to 10 weeks old (although, some kits continue to nurse occasionally until they are 4 months old.)  By four months old, young fishers can hunt for themselves and start to disperse by 5 months old.  Fishers establish home ranges by the time they are a year old.

Females experience a postpartum estrus and mate again shortly after giving birth.

Females reach sexual maturity by one year old and breed once a year after that.  Males reach sexual maturity by 2 years old.4

Notes of Interest

Fishers are also referred to as: 
Pekans, Fisher Cats, Black Cats, Wejacks, and American Sables.5

There has been limited success trying to breed fishers in captivity.

In the past, fisher populations were severely impacted by the fur trade.  However, the demand for their pelts has decreased and populations have been recovering (particularly in New York and southern Ontario, where populations are expanding into suburban areas.)  Due to range expansion, there have been reports of fisher attacks on domestic animals and children, attracted to human-inhabited areas by food and garbage.  Fishers are known to react aggressively toward threats or when startled and caution should be exercised in the presence of this species.

Certain fisher populations have been considered for protection under the Endangered Species Act, such as those living in southern zones of the Sierra Nevada.6

1. http://animaldiversity.ummz.umich.edu/accounts/Martes_pennanti/
2. http://animaldiversity.ummz.umich.edu/accounts/Martes_pennanti/
3. http://www.mnh.si.edu/mna/image_info.cfm?species_id=152
4. http://animaldiversity.ummz.umich.edu/accounts/Martes_pennanti/
5. http://www.mnh.si.edu/mna/image_info.cfm?species_id=152
6. http://animaldiversity.ummz.umich.edu/accounts/Martes_pennanti/

http://animaldiversity.ummz.umich.edu/accounts/Martes_pennanti/
http://www.nhptv.org/natureworks/fisher.htm  
http://www.mnh.si.edu/mna/image_info.cfm?species_id=152
http://www.fws.gov/mountain-prairie/species/mammals/fisher/  

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Mammals

Nutria Rat – information

Nutria Rat

General

The Nutria Rat (Myocastor coypus,) of the order rodentia, is a large, semi-aquatic rodent native to southern South America. It has been described as “a cross between a beaver and a New York sewer rat.”1 Now found on 4 continents, and recognized as an invasive wildlife species in the United States (present in 22 states,) measures are being taken to control populations and manage the devastation this species is wreaking on coastal ecosystems.

Description

Nutria rats are large, robust rodents that are well equipped for an aquatic life. They are sometimes mistaken for beavers or muskrats due to similar physical traits, but are approximately 1/3 the size of beavers and larger than muskrats. Their small ears, eyes, and nostrils are situated high on their large heads and remain above water during swimming.2 Valves located in their mouths and nostrils prevent water intake when submerged. Nutria rats have a total of 20 teeth, including 4 large yellow/orange incisors that protrude from the front of their mouths. Their white whiskers are 3” to 5” long. Glands located at the corners of the mouth produce oils that are combed through the fur to provide waterproofing.3 Nutria rats have partially webbed back feet (all back toes are connected by webbing except one that is used much like a thumb.) The front feet, which are smaller and not webbed, have 4 toes that are similar and one toe that is smaller and functions similar to a thumb.4 Nutria rats have stout bodies that appear hump-backed when not in the water. They reach a mature weight of 15 lbs. to 22 lbs. (males tending to be larger,) and a mature length of 27” to 41” (including the tail, which tends to make-up over half of the overall length.) Their tails are thick, round and scaly, with sparse bristly hairs. When swimming, the tail glides smoothly through the water behind the body. Because of a lack of insulation on their tails, Nutria rats living in northern climates tend to loose portions of their tails to frostbite during hard winters.5

Their coats are made of a coarse outer layer comprised of yellow to dark brown shaggy hairs and a lush undercoat (called nutria,) that is soft and grey. It is the undercoat that is sought by trappers. Their muzzles and chins are white. Although uncommon, albino Nutria rats have been observed in the wild.

Nutria rats are strong swimmers and spend the majority of their time in the water (since they are more agile in the water than on land.) They see well underwater and can stay submerged for up to five minutes.

Nutria rats are shy and nocturnal so they are not often seen in the wild. However, they are social within their species and live in large colonies.

On average, Nutria rats live for 8 to 10 years.

Habitat

Nutria rats have adapted to a variety of habitats but always maintain a close proximity to fresh or brackish water. They may be found along riverbanks, lakeshores or coastlands, in wetlands, farm ponds, drainage systems, canals, bayous, swamps, marshes, overgrown lots, or even in cities beneath buildings. They build burrows near water in low vegetation or root systems. The inner chambers of their dens are lined with grasses and located above the water line but are accessed by entrances that are up to 24” in diameter and 12” to 24” below the surface of the water. In marshes, Nutria rats build flat platforms of dead vegetation for feeding, birthing, or grooming purposes.6

Within their habitats, Nutria rats are vulnerable to alligators, large snakes, birds of prey, and turtles.7

Location

Nutria rats are only native to southern South America. However, because of both accidental and intentional introduction, they can now be found in Canada and 22 of the United States (most highly concentrated along the Gulf Coast, but also found in eastern and northwestern coastal regions,) Europe, and Asia. Louisiana has an estimated population of 5 million Nutria rats.8 The fur of this species was once popular in the fur trade and Nutria rats were domesticated around the world on fur farms (the first recorded domestication in the U.S. was in1889.) Wild populations that were started by farm escapees exploded in size when the nutria fur trade collapsed (during the 1940’s in the U.S.,) forcing farmers to release their rats into the wild because they could no longer afford to keep them. Wild populations were intentionally expanded by wildlife agencies and private companies who attempted to use the rats to control invasive or noxious weeds.9

Diet

Nutria rats are omnivorous surface eaters who often over-harvest their dietary staple, aquatic vegetation (including the roots, stems, leaves, and bark.) They do not eat vegetation in the water, but rather swim with it or carry it back to their platforms to feed. Their diets also include small animals, such as snails and mussels. Nutria rats are capable of consuming 25% of their own body weight every day.10 Their eating habits have proven detrimental to coastal ecosystems, destroying vegetation that is important in the prevention of soil erosion. They are also troublesome to farmers, devouring crops such as rice, corn, alfalfa, wheat, oats, barley, sugarcane, peanuts, and vegetables.11

Reproduction

Nutria rats are prolific reproducers. Typically, a male will live in the same burrow as several females and breed throughout the year. Each female has, on average, 2 to 3 litters a year, each consisting of 1 to 11 young (but usually 4 to 6.) It has been observed that litter sizes are cyclical, with a large litter of 4 to 6 young followed by a small littler of 2 to 4, and so on.12 Gestation lasts slightly longer than 4 months and the young reach sexual maturity in 4 to 8 months, leaving their mother after only 1 to 2 months. Females’ teats are situated high on their backs so the young may feed while she is swimming. Females are ready to breed within days of birthing a litter.13

Notes of Interest

Common names of the Nutria rat include coypu, coypu rat, swamp beaver, and nutria.14

The aquatic diet of the Nutria rat is partially to blame for an increased rate of coastal erosion. In Louisiana, with a population estimated to be around 5 million, the nutria rat is responsible for a rate of erosion of 40 square miles per year. This species damages and destroys vegetation that is necessary for anchoring soil, turning marshes and wetland environments into open water. Additionally, Nutria rats have been known to undermine levees, dams, buildings and roadbeds. Nutria rats have also negatively affected agricultural resources and are responsible for disease transmission. They may carry tuberculosis, septicemia, blood flukes, tapeworms, liver flukes, and a type of nematode that causes “nutria itch,” a rash that is spread through water contaminated by feces and urine.

Federal, state, and local governments are working closely with wildlife agencies to manage Nutria rat populations and protect native vegetation and resources.15

1. http://www.usatoday.com/story/news/nation/2013/05/09/nutria-rats-louisiana-erosion/2147077/
2. http://animals.nationalgeographic.com/animals/mammals/nutria/
3. http://www.aphis.usda.gov/publications/wildlife_damage/content/printable_version/fs_nutria10.pdf
4. http://www.nationaltrappers.com/nutria.html
5. http://www.aphis.usda.gov/publications/wildlife_damage/content/printable_version/fs_nutria10.pdf
6. http://www.nationaltrappers.com/nutria.html
7. http://www.aphis.usda.gov/publications/wildlife_damage/content/printable_version/fs_nutria10.pdf
8. http://www.usatoday.com/story/news/nation/2013/05/09/nutria-rats-louisiana-erosion/2147077/
9. http://www.aphis.usda.gov/publications/wildlife_damage/content/printable_version/fs_nutria10.pdf
10. http://www.columbia.edu/itc/cerc/danoff-burg/invasion_bio/inv_spp_summ/Myocastor_coypus2.html
11. http://www.aphis.usda.gov/publications/wildlife_damage/content/printable_version/fs_nutria10.pdf
12. http://www.nationaltrappers.com/nutria.html
13. http://www.aphis.usda.gov/publications/wildlife_damage/content/printable_version/fs_nutria10.pdf
14. http://www.columbia.edu/itc/cerc/danoff-burg/invasion_bio/inv_spp_summ/Myocastor_coypus2.html
15. http://www.aphis.usda.gov/publications/wildlife_damage/content/printable_version/fs_nutria10.pdf

http://animals.nationalgeographic.com/animals/mammals/nutria/
http://www.usatoday.com/story/news/nation/2013/05/09/nutria-rats-louisiana-erosion/2147077/
http://www.aphis.usda.gov/publications/wildlife_damage/content/printable_version/fs_nutria10.pdf
http://www.columbia.edu/itc/cerc/danoff-burg/invasion_bio/inv_spp_summ/Myocastor_coypus2.html
http://www.nationaltrappers.com/nutria.html

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Mammals

North American Porcupine – Information

North American Porcupine

General

The North American Porcupine (Erethizon dorsatum,) is the largest species of porcupine and the only one that can be found in the United States and Canada. Within their range, they are the second largest species of rodent, aside from the beaver. Although not an aggressive animal, porcupines are equipped with a coat of sharp defensive quills that makes them easily identifiable. This species faces no risk and enjoys an extensive geographic range.

Description

The North American Porcupine is easily identifiable by their stout lumbering bodies and spiny coats. NAP’s reach a mature length of 33” to 46” (the tail comprises approximately 1/3 of that length.) Adults weigh between 12 to 35 lbs. (males tend to be the larger sex.)1 NAP’s have small ears, small heads, and large front teeth that aid in consuming wood. There is a prominent diastema between the front teeth that allows them to draw in their lips while gnawing. Their skulls exhibit a lack of canines. Like other hystricomorphs, they have unique chewing muscles.

The name porcupine is derived from the Latin for “quill pig.” Their coats are comprised of three types of hair: a soft, dense woolly undercoat, long, course, brownish-yellow to black guard hairs, and quills. There are 24 species of porcupines that have coats made of more than 30,000 quills that act as sharp defense mechanisms. These tubular quills are filled with a spongy matrix (making them rigid but light,)2 and cover a porcupine’s head, back, sides and tail. The longest quills are found on the rear and may be up to 12” long, while the shortest quills are on the cheeks.3 The quills located within a central black line on their lower backs and tails are accented with white. This contrast appears on porcupines by three months old and acts as a preliminary warning to approaching predators (many being color blind.)4 Porcupines are non-aggressive mammals that only attack if they are unable to escape a threat. Typically, their quills lay flat but in defense, these quills become erect to fend-off predators. If an attack occurs, the porcupine lashes out at the predator, and the quills detach from the porcupine’s body (despite popular belief, porcupines cannot throw their quills.) The quills have sharp tips and barbs that embed into the predator’s body. The predator’s body heat causes the barbs to expand and muscle movements push the quills further into the predator’s skin. Embedded quills may cause infection or death.5 Growing new quills is possible but difficult for porcupines. To avoid losing quills, porcupines exhibit several warning behaviors to fend off predators before an attack ensues. These include visual cues (contrasting warning colors and erected quills,) acoustic clues (teeth chattering,) and chemical clues (porcupine’s emit a strong chemical odor when threatened.)

Porcupines are well suited for climbing and spend much of their time in trees. Different trees are chosen for feeding and resting. Their feet feature specific adaptations that allow them to grip surfaces and brace themselves high off the ground. They have four long claws on their front feet in addition to a vestigial thumb, and five long claws on the back feet. The palms and soles of their feet are hairless and have pebbly surfaces that create friction with surfaces. Porcupines often secure themselves when climbing with their hind feet and grasp food with their front feet. The quills are also useful climbing implements. Quills located on the tail are thrust into the tree to help stabilize the porcupine and prevent downward sliding. Porcupines are known to spend the majority of time in trees; however, this behavior is directly related to the amount of ground cover available and the types of predators within a habitat. If appropriate ground cover exists, a porcupine will tend to forage and take cover on the ground more often. NAP’s are also good swimmers, aided by their lightweight quills that help keep them afloat.

They are solitary animals but are known to den and forage with other porcupines during the winter, most likely for protection from predators. These groups do not tend to reflect mating preferences. They build their dens in hollow trees, rock piles or caves. These dens are not used for hibernation, rather sporadically throughout the winter during severe weather.

Both males and females establish and defend territories. Males establish territories that overlap those of several females, but never that of another dominant male. Females’ territories tend to be consistent in size but the size of a male’s territory reflects his age and dominance. Juvenile males settle and establish their initial territories within their birth territories. As males mature, their territories increase in size. Juvenile females part from their birth territories and establish new territories before they reach maturity.6

Porcupines use several methods of communication with other members of their species and with predators. They are vocal animals, creating sounds that include moans, grunts, coughs, wails, whines, shrieks and tooth chattering (used to warn predators.)7 NAP’s also emit chemical signals and display the white/black markings on their quills when confronted by a threat. Their padded palms and soles provide them with a keen sense of touch.

Porcupines in the wild may live up to 18 years. It has been observed that a porcupine’s life expectancy is proportionate to the health and longevity of their grinding teeth. By 12 years of age, these teeth begin to show wear, resulting in a diminished diet and, therefore, a diminished body mass.

Habitat

NAP’s have adapted to many types of climates due to their extensive range that includes a variety of elevations and geographic locations. They may be found living in coniferous or deciduous forests, savannahs, grasslands, mountains, or open tundra. Their behaviors are impacted by their habitat. In the Pacific Northwest, porcupines tend to be more ground dwelling, while populations in New York are primarily arboreal.

Within their habitats, porcupines have many predators, despite their weaponry. These include bobcats, coyotes, wolves, lynx, mountain lions, fishers, wolverines, and birds of prey. These predators have adapted to the porcupine’s weaponry, attacking from the front and flipping the porcupine over exposing its vulnerable stomach.

Location

The NAP has the most northern geographic range of all porcupine species. Their range includes most of North America, spanning from the Arctic Ocean to northern parts of Mexico.

Diet

Porcupines have herbivorous diets that vary seasonally. During the spring and summer, their feeding rates decrease due to the increased availability of and their preference for high protein foods. Their diets include leaves, clover, twigs, bark, grasses, flowering herbs, and fruit (especially apples.) The herbivorous nature of their diets affects their sodium metabolism, causing porcupines to crave salt. As a result, they are driven to chew on wooden implements, structures, vehicles, and other items with residual salt. They are generally nocturnal foragers.

Reproduction

They breed once a year, between late summer and early fall. Females secrete chemicals, make high-pitched vocalizations, and mark with urine to alert males of their 8 to 12 hour estrous period that occurs prior to ovulation. Sexually mature males fight to establish sexual dominance, using loud vocalizations, biting, and erect quills. The dominant, and often largest, male establishes a breeding territory (which he may use for up to three seasons,) and wins breeding rights (and must defend the pre-estrous female for 1 to 4 days until copulation.) The dominant male performs a peculiar mating dance, which includes spraying the female’s head with urine. This display will continue until the female becomes receptive to the dance and mating. A male may mate with several consenting females.

Copulation takes place on the ground and may last for several hours. Mating ends when a vaginal plug is formed by an enzymatic action that occurs in the semen. The plug prevents other males from mating with the female.

After a gestational period of 210 days, the female gives birth to a single baby. The newborn has soft quills (which harden an hour after birth,) and weighs between .9 to 1.2 lbs.

The mother nurses her young for approximately 130 days, although young porcupines can eat solid food within a few days of birth. For the first 6 weeks, the baby remains close to its mother. The female sleeps and feeds in trees during the day (leaving her baby hidden on the ground nearby,) and returns to her baby at night.

By six weeks old, the baby begins following its mother to feeding trees, remaining at the base while she feeds. Over the next few months, the distance between the mother and her offspring increases during foraging trips and by 5 months old, the juvenile is independent (left by its mother to survive alone during the upcoming winter.)

Female reach sexual maturity by 25 months old. Males do not reach sexual maturity until 29 months old.

Notes of Interest

While quills are obviously dangerous for predators, they pose some risk to porcupines as well. Porcupines can fall out of trees, resulting in self-impalement. Additionally, the force it takes to impale a predator with quills might exceed the weight of the porcupine, resulting in a difficult or impossible separation of quills from the porcupine.

Native Americans once revered the porcupine for its meat and quills (which were used as decoration and to establish status.)

NAP’s are considered a pest by the timber industry. Their tendency to feed on bark and twigs leaves trees stunted or deformed and unsuitable to be turned into lumber.8

1. http://animals.nationalgeographic.com/animals/mammals/porcupine/
2. http://animaldiversity.ummz.umich.edu/accounts/Erethizon_dorsatum/
3. http://www.nhptv.org/natureworks/porcupine.htm
4. http://animaldiversity.ummz.umich.edu/accounts/Erethizon_dorsatum/
5. http://www.nhptv.org/natureworks/porcupine.htm
6. http://animaldiversity.ummz.umich.edu/accounts/Erethizon_dorsatum/
7. http://animals.nationalgeographic.com/animals/mammals/porcupine/
8. http://animaldiversity.ummz.umich.edu/accounts/Erethizon_dorsatum/

http://animals.nationalgeographic.com/animals/mammals/porcupine/
http://www.nhptv.org/natureworks/porcupine.htm
http://animaldiversity.ummz.umich.edu/accounts/Erethizon_dorsatum/

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Mammals, Wildlife

American Marten – Martes Americana

American Marten

General

The American Marten, Martes Americana, also know as the pine marten, is a member of the mustelid family, related to badgers, weasels, mink and otters. They are small, slender mammals known for their soft, shiny coats. The American Marten was widespread across the northeastern United States and Canada until hunting and forestry limited this species’ size and geographic range.

Description

American Martens are small predators with long slender bodies, pointed snouts, large eyes, and small cat-like ears. Their feet have curved, retractable claws and large pads (relative to their weight.) These footpads are insulated by long tufts of hair and make it possible to navigate across deep snow.1

Adult males reach a mature length of 20” to 26.5” (their long, bushy tails account for approximately 1/3 of their overall length,) and weight of 1 lb. to 2.9 lbs. Females tend to be smaller (weighing between .6 lb. to 1.9 lbs.) and lighter in color.2 Their long, soft, shiny coats vary in color between individuals (ranging from a light brown or red brown, to a golden brown or buff yellow,) with hair tending to be paler on their heads and undersides, and darker on their legs and tails. They have a cream patch on their chest.

American Martens are solitary animals and are most active at night. They are most often found alone in the wild and only interact during the mating season. Although solitary, they are also curious animals that have been spotted peaking through windows.3 American Martens do not hibernate and remain active all winter. To keep warm during cold months, martens tunnel beneath the snow and huddle amongst tree roots for warmth.4 American Martens are terrestrial mammals that are somewhat arboreal and accomplished swimmers (they are even capable of swimming under water.)

Home ranges of the American Marten vary in size based on gender, location and food supplies. Males’ ranges are approximately 3 square miles while females tend to establish ranges of less than one square mile. Population densities also fluctuate. A healthy habitat can support a density of .7 martens per square mile, while an unhealthy habitat may only support .2 martens per square mile.5

American Martens have complex systems of communication (chemical, vocal, and physical.) Like other members of the mustelid family, American Martens have anal scent glands that secrete a strong odor used to mark territories.6 They also use scent marking to highlight their arboreal trails. Their vocalizations include huffs, screams, and chuckles. Physical interaction is an important component of mating, and the relationship between a mother and her young. American Martens, like other mustelids, are believed to also communicate through body posturing.

The American Marten has a life expectancy of 17 years in captivity. The life expectancy of wild martens is not well documented; however, females in the wild have been known to breed at ages up to 12 years.

Habitat

American Martens can be found in mature, temperate northern forests at any elevation. They den in ground burrows, crevices or hollowed trees. Within their habitats, they are vulnerable to hawks, owls, fishers, bobcats, and humans.

Location

American Marten populations are distributed throughout northern forests of North America, from Newfoundland and Nova Scotia to Alaska and the northern Rockies. During Colonial times this species was abundant in the northeastern United States, including New York, Maine, Minnesota, and Wisconsin. However, loss of habitat due to forestry practices has limited the marten’s range. Reintroduction programs that were implemented in certain areas have experienced some success in population recovery.

Diet

American Martens are opportunistic feeders. Their diets are mainly comprised of small mammals but may also include seasonal fruit and seeds, fish, birds, insects, and carrion. They are terrestrial hunters who do the majority of their hunting on the ground at dawn and dusk. However, they have been known to chase red squirrels (a favorite dietary staple,) and other arboreal species through the trees. Martens attack their prey with a quick bite to the back of the neck.7 In the winter, Martens tunnel through the snow to hunt below the surface.8

Reproduction

The breeding season of the American Marten occurs between June and August. In captivity, females in estrus have been observed to have between 1 and 4 periods of receptiveness during a breeding season, each lasting between 1 and 4 days. These periods are separated by 6 to 17 days. Females in estrus use scent marking to communicate their sexual maturity and readiness. Their long courtships are active and playful, including wrestling and tumbling, and typically occur with more than one partner.

While gestation lasts for a total of 220 to 275 days, the fertilized eggs only develop for the last month of this period. Although eggs are fertilized immediately after copulation, they do not implant in the uterine lining until around February, in a process known as delayed implantation. A litter of 1 to 5 blind, naked young are born in a den of dried vegetation in late March or early April.

There is not a lot of information regarding parental care in the wild. Because the American Marten is a solitary animal, males are not likely to play a large role in the care of young. However, adult males have been observed with mature females and immature young in the wild, likely their own. Females are known to provide care and nourishment for the first few months of her young’s lives, until she leaves them to have another litter.

The young grow quickly. Their eyes are open by 39 days old and they are fully weaned by 42 days old. By 3.5 months old, the young are fully-grown and are left by their mother, who is ready to mate again.

American Martens reach sexual maturity by 15 to 24 months old.

Notes of Interest

The fur of the American Marten is very valuable. However, over hunting and forestry have greatly diminished populations in parts of their range and pelt collection is now controlled in some areas.9

The American Marten is sometimes incorrectly referred to as the Pine Marten, a name derived from a Eurasian species of marten.

1. http://www.dec.ny.gov/animals/45531.html
2. http://animaldiversity.ummz.umich.edu/accounts/Martes_americana/
3. http://www.dec.ny.gov/animals/45531.html
4. http://www.dnr.state.mn.us/mammals/americanmarten.html
5. http://animaldiversity.ummz.umich.edu/accounts/Martes_americana/
6. http://www.dec.ny.gov/animals/45531.html
7. http://animaldiversity.ummz.umich.edu/accounts/Martes_americana/
8. http://www.dnr.state.mn.us/mammals/americanmarten.html
9. http://animaldiversity.ummz.umich.edu/accounts/Martes_americana/

http://animaldiversity.ummz.umich.edu/accounts/Martes_americana/
http://www.dnr.state.mn.us/mammals/americanmarten.html
http://www.dec.ny.gov/animals/45531.html
http://www.mnh.si.edu/mna/image

Mammals, Wildlife

Bobcat – Lynx rufus Information

Bobcat, Felis rufus

General

The Bobcat, Felis rufus, is the most abundant and widespread native wild cat in North America, named for its short tail that has a docked or “bobbed” appearance. The bobcat is an elusive mammal has been forced to become highly adaptive and can be found in a variety of environments because of habitat loss due to human development.

Description

Bobcats are nearly twice the size of a common housecat, they measure 26” to 41” from head to tail (the tail measuring 4” to 7” in length,) and 17.5” to 23” tall at the shoulder. They are named for their short tails that appear “bobbed” or cut. On average, females are smaller than males. Adult bobcats weigh between 11 lbs. and 30 lbs. Bobcats have long legs and large paws (1) and make tracks that are approximately 2” in diameter (about double the width of housecat tracks) (2). They can be easily identified by the short tufts of hair on their ears (similar to those of the Canada Lynx,) and long, striped ruffs of hair along the sides of the head that create the illusion of sideburns.

Bobcats have an overall brown, buff, or brown-red coat accented by a white underside, black-tipped tail and ears, and dark stripes and spots on the body. In the winter, their coats may grey or dull.3

Bobcats are elusive and nocturnal, making them hard to observe in the wild. They tend to be solitary creatures and only interact during the mating season. Their home ranges are between .5 and over 2.5 square miles, depending on the time of year and location. Male bobcats have larger ranges than females and tend to overlap their ranges with those of several females and sometimes that of another male. Female bobcat ranges do not overlap. Bobcats are territorial and use scent markers to distinguish their ranges and repel intruders. These scent markers may include urine, feces, anal secretions, scratchings, and scrapes (piles of debris collected by a bobcat and marked with their scent.) Bobcats also communicate through sound, although this is typically reserved for the mating season when bobcats produce yowls and hisses. In addition to communication, bobcats also use keen vision, smell, and hearing to navigate their environments and interactions.

Bobcats spend the majority of time on the ground but are agile climbers and can swim.

In the wild, bobcats live an average of 10 to 12 years while in captivity they may live as long as 32 years. (4)

Habitat

Bobcats have adapted to a diverse range of temperate habitats, including forests, deserts, swamps, brush land, mountains, and suburban areas (5). This diversification has been a necessary result of habitat loss due to development. They prefer habitats with minimal snow accumulation, since (unlike the lynx) bobcat paws are not adapted to navigate across deep snow. (6)

Bobcats build hidden dens in hollow trees, thickets, brush piles, and rocky outcroppings or crevices. While hidden, these dens can be recognized by the strong odors that tend to come from them.

Adults face few threats in their habitats other than humans. Natural enemies are coyotes, wolves and mountain lions. Their kittens are prey to large owls, coyotes, and foxes.

Location

Bobcats can be found across most of North America, from southern parts of Canada through Mexico. Within the United States, bobcat populations tend to be densest in the southeast (7).

Diet

Bobcats are opportunistic carnivores and fierce hunters, whose diets consist mainly of rabbits, birds, rodents, and small game (although they are capable of taking down prey much larger then themselves, such as deer.) They have also been known to prey on domestic animals – small dogs as well as outdoor cats. Bobcats are stealthy hunters, using sight and sound to stalk their prey. They wait motionless, then pounce up to 10’, grabbing their prey by the neck and biting through the vertebrae. If a bobcat does not consume its entire kill at once, it will cover the remains with debris or snow and revisit the carcass for future feedings.8

Breeding

Bobcats are solitary animals and only interact for courtship during the mating season. Breeding occurs once a year (usually in the spring,) during which time females may have multiple partners. After mating, male bobcats play no additional part in reproduction or rearing of the kittens.

Gestation lasts for 60 to 70 days, at which point the female will find a private den and have a little of one to six kittens. The kittens open their eyes at 10 days old and nurse for the first two months. Before the young set out on their own at 9 to 12 months old, their mother brings them meat and teaches them to hunt. Female bobcats reach sexual maturity by one year old, and males by two years.9

Notes of Interest

Bobcats are still trapped for their fur in certain parts of their range.

They are the most widespread and abundant wild cat native to North America. It is estimated that there are as many as one million bobcats in the United States alone.10 With that said, bobcats are quite rare in certain parts of their range, warranting hunting regulations and protection acts.

The Mexican bobcat, Lynx rufus escuinapae, a subspecies of Lynx rufus, is native to central Mexico and listed as endangered by the U.S. Fish and Wildlife Service.11

Bobcats are also referred to as Wildcats, Bay Lynx, Barred Bobcats, Pallid Bobcats, and Red Lynx.12

1. http://animals.nationalgeographic.com/animals/mammals/bobcat/
2. http://wdfw.wa.gov/living/bobcats.html
3. http://www.nhptv.org/natureworks/bobcat.htm
4. http://animaldiversity.ummz.umich.edu/accounts/Lynx_rufus/
5. http://animals.nationalgeographic.com/animals/mammals/bobcat/
6. http://wdfw.wa.gov/living/bobcats.html
7. http://animaldiversity.ummz.umich.edu/accounts/Lynx_rufus/
8. http://wdfw.wa.gov/living/bobcats.html
9. http://animaldiversity.ummz.umich.edu/accounts/Lynx_rufus/
10. http://animals.nationalgeographic.com/animals/mammals/bobcat/
11. http://animaldiversity.ummz.umich.edu/accounts/Lynx_rufus/
12. http://www.mnh.si.edu/mna/image_info.cfm?species_id=144

http://animals.nationalgeographic.com/animals/mammals/bobcat/
http://animaldiversity.ummz.umich.edu/accounts/Lynx_rufus/
http://www.mnh.si.edu/mna/image_info.cfm?species_id=144
http://www.nhptv.org/natureworks/bobcat.htm
http://www.tpwd.state.tx.us/huntwild/wild/species/bobcat/
http://wdfw.wa.gov/living/bobcats.html

Mammals, Wildlife

Striped Skunk – Mephitis mephitis, Information

General: The Striped Skunk (Mephitis mephitis) is an easily identifiable member of the STRIPED SKUNK: a common North American skunk (Mephitis mephitis) usually with white on the top of the head that extends posteriorlyweasel family, known for its graphic coloration and extreme odor used for defensive purposes (mephitis meaning “noxious vapor” in Latin.) This shy nocturnal animal is an opportunistic feeder that can often be spotted in backyards searching for its next meal. This is an abundant species with populations across much of North America and is listed as Least Concern on the IUCN Red List.

Description: Striped skunks are known for their graphic black and white coloration. Their all-black bodies are marked with two bold white stripes running the length of the back, originating on the head where they meet in a triangular shape to form a ‘white cap.’ A third white stripe runs between the eyes, from the forehead to the base of the snout. Bushy tails are 6” to 12” in length and are usually a mottled combination of black and white hairs, although the solid stripes may extend onto the tail. Stripe width and length are determined on an individual basis. Color patterns may vary, resulting in the identification of four subspecies. These subspecies typically occur because of geographic barriers1.

Adults grow to an average length of 22” to 32” and a weight of 2.5lbs. to 10lbs., comparable to a housecat, males reaching a larger mature size than females. Striped skunks have small heads with small features and short legs with plantigrade feet and five partially webbed toes2. The front toes have long claws that aid in digging. Their short legs do not allow for running, instead Striped skunks move with distinctive waddles3.
Wild Striped skunks have a life expectancy of 2 to 3 years. In some regions, nearly 90% of skunks perish during their first year. Striped skunks living in captivity have survived as long as 15 years4.

Striped skunks are nocturnal, emerging from their burrows at dusk to search for food. During the day they reside in protective dens, often built using another animal’s abandoned burrow, such as a fox or woodchuck. Striped skunks may also build their own den in the ground or a hollow log or under a building, using their long claws to excavate5. These dens may contain up to five entrances and multiple chambers.
Striped skunks enter a period of inactivity from the late fall to March. Communal winter dens accommodate several females with their young and, on occasion, a male (although males usually live in a separate, solitary den.) Males tend to emerge on mild winter days in search of food, while females remain inactive throughout this period.

Skunks are notorious for their mechanism of defense. Because their coloration offers them no camouflage in their native habitats, they require a physical defense that develops when they are just a few weeks old. When facing an extreme or mortal threat, these animals use two glands located on either side of the anus to accurately spray an intense-smelling compound up to 15’ (the smell can travel for up to a mile.) This foul oily spray is directed at threats or predators and may cause extreme discomfort in the eyes or respiratory system, and nausea. Before spraying, Striped skunks display a series of warning behaviors to ward off predators, including hissing, stomping, arching the back, and erecting the tail.
Striped skunks use scent to announce their presence and/or reproductive status to other individuals, since they have excellent senses of smell. They may also use changes in posture and a variety of sounds to communicate (their good sense of hearing allows them to register hisses, screams, squeals, and chattering made by other skunks6). Skunks are known to have poor vision, resulting in many collisions with automobiles.

Habitat: Striped skunks prefer open areas in close proximity to water. Habitats include woods, grassy fields, agricultural clearings, parks and suburban areas. In their native habitats Striped skunks have several predators, including owls, hawks, bobcats, foxes, coyotes, and dogs.

Location: Striped skunks are native to the nearctic region, found across most of North American, from central Canada to northern Mexico7.

Diet: Striped skunks are opportunistic feeders, scavenging for a diet that varies based on season. As omnivores, skunks’ diets include insects (with beetles and beetle larvae, caterpillars, ants, wasps, grasshoppers, crickets, bees, millipedes and centipedes making up roughly 70% of their diets8,) worms, snails, salamanders, crustaceans, turtle eggs, ground-nesting birds and their eggs, slugs, frogs, mice, squirrels, shrews, small rabbits and snakes, fish and fruits and vegetation (including berries, grass, leaves, buds, carrion and nuts)9. Striped skunks commonly dig in search of food (such as grubs,) leaving shallow divots in a lawn that resemble those dug by squirrels.

Reproduction: Striped skunks are a solitary species and typically only interact when mating in the late winter or early spring. Female skunks are monestrous but may have a second estrus in the case of a failed initial pregnancy and males are polygamous, usually seeking out several partners in one mating season. Females build a nest of dried leaves, grass, and weeds usually located in one of the chambers in her den. The nest may also be located under a thicket of dense vegetation, under a rock, or in a burrow. Females nurture the unborn internally, with gestation lasting between 60 and 77 days. Litters contain anywhere from 1 to 10 young (but on average contain 4 or 5,) that are born blind, deaf, and immature, weighing only 33g10. Females provide the helpless young with milk for a month after birth while males provide no care. After about 6 weeks in the den, the young will begin following their mother out hunting and will continue doing so until fully grown, reaching sexual maturity in 10 months11.

Encounters of the Skunk Kind…

It is important to remember that skunks use their spray defense as a last resort, when they feel they or their young are being gravely threatened. Avoiding these animals and knowing the warning signs are your best defenses against you or your pets getting sprayed. The first step is being aware of your surroundings, especially at night when these animals are most active. Keep your pets on a leash or restrained in a fenced-in yard away from areas where skunks may have dens or be feeding. Limit pets’ outdoor-time at night and make sure to supervise them. Also consider eliminating areas that may attract skunks, such as abandoned animal dens or cavities in the ground, open-access to sheds or garages, and animal food storage. If a skunk is encountered, try and remain calm. These generally easy-going animals may ignore humans and other animals all together if they don’t feel threatened. If you stand still and passive, the skunk may wander away from the area. Calmly walk away and remove pets from the area.

You can tell if a skunk feels threatened by looking for these signs:

• Hissing
• Stamping feet and forward lunges
• Raised tail
• Turning of the posterior in your direction

If you or your pets are unfortunate enough to be sprayed, several steps should be taken to avoid physical discomfort and ease the potency of the smell. If the sulfur-alcohol compound12 emitted by the skunk has gotten into your or your pet’s face, immediate flushing with clean water or a saline solution is necessary (making sure to flush your pet’s eyes, nose, and mouth.) This compound may cause severe discomfort and possibly temporary blindness. If your pet continues to rub his/her eyes after rinsing, contact your veterinarian and try to prevent additional rubbing (as this may cause more trauma to the eyes.) If this compound is inhaled (at close range,) it may cause respiratory inflammation and discomfort and extreme nausea13. Proper attention should be sought from medical professionals for you or your pet if symptoms persist or are severe.

In order to eliminate the strong odor, the chemicals emitted by the skunk must be neutralized. The following mixture may be applied to your skin, hair, some clothing, and your pet:

1 quart 3% hydrogen peroxide
¼ cup baking soda
1-2 tsp. liquid dish soap

Combine these ingredients and apply immediately using rubber gloves, avoiding your or your pets’ eyes. Keep in mind this mixture will bubble. Rinse, and repeat. For external use only. Keep in mind, hydrogen peroxide is a bleaching agent and should not be left on for more than 2 minutes.

Discard any remaining mixture. Do not store in a closed container because oxygen released will cause the container to explode14.

If possible, discard any contaminated clothing since this oily mixture soaks in to many fabrics. The above mixture may be applied to some clothing but could bleach colors. Contact your local dry cleaner regarding garments you wish to have washed.
If clothing, your home, or other items have absorbed the smell indirectly, you may wash using a solution of household bleach to neutralize odors (1 cup bleach per gallon of water.)
Commercial cleaning solutions, shampoos, or sprays (containing neutroleum alpha) may be available at your veterinarian’s office or your local store that specifically target skunk odors15.

*If you encounter a skunk during the day it is important to contact the appropriate authorities. Skunks are primarily a nocturnal species and abnormal activity during the day could indicate a rabid animal. If you or your pet is bitten (which is uncommon but can happen,) you should immediately contact your doctor or veterinarian, as well as your local health department.

Notes of Interest:

Skunks are one of the four primary carriers of the Rabies virus. Other primary carriers include bats, raccoons, and foxes16.

Before writing skunks off completely, consider their positive attributes, including their tendency to aid in pest control, feeding on mice, squirrels, moles, caterpillars and grubs.

While skunks secrete a very undesirable smell when threatened, their regular musk is a common ingredient in perfumes17.

A member of the weasel family (along with minks, and ermines,) the skunk has a thick coat of glossy fur. Historically, their hides were sought after by the fur industry. In recent decades, this fur has seen a decline in value18.

Skunks may be domesticated and some households choose to keep skunks as pets (having the scent glands removed.) This practice, however, is illegal in many states due to this species’ tendency to carry the rabies virus.

Footnotes

1. http://animaldiversity.ummz.umich.edu/accounts/Mephitis_mephitis/
2. http://animaldiversity.ummz.umich.edu/accounts/Mephitis_mephitis/
3. http://www.fcps.edu/islandcreekes/ecology/striped_skunk.htm
4. http://animaldiversity.ummz.umich.edu/accounts/Mephitis_mephitis/
5. http://www.fcps.edu/islandcreekes/ecology/striped_skunk.htm
6. http://animaldiversity.ummz.umich.edu/accounts/Mephitis_mephitis/
7. http://animaldiversity.ummz.umich.edu/accounts/Mephitis_mephitis/
8. http://animaldiversity.ummz.umich.edu/accounts/Mephitis_mephitis/
9. http://www.fcps.edu/islandcreekes/ecology/striped_skunk.htm
10. http://animaldiversity.ummz.umich.edu/accounts/Mephitis_mephitis/
11. http://www.fcps.edu/islandcreekes/ecology/striped_skunk.htm
12. http://www.humanesociety.org/animals/skunks/tips/solving_problems_skunks.html
13. http://www.weather.com/outlook/homeandgarden/pets/articles/d82
14. http://www.humanesociety.org/animals/skunks/tips/solving_problems_skunks.html
15. http://www.humanesociety.org/animals/skunks/tips/solving_problems_skunks.html
16. http://www.humanesociety.org/animals/skunks/tips/solving_problems_skunks.html
17. http://www.fcps.edu/islandcreekes/ecology/striped_skunk.htm
18. http://animaldiversity.ummz.umich.edu/accounts/Mephitis_mephitis/

http://www.fcps.edu/islandcreekes/ecology/striped_skunk.htm
http://animaldiversity.ummz.umich.edu/accounts/Mephitis_mephitis/
http://www.tpwd.state.tx.us/huntwild/wild/species/skunk/
http://www.weather.com/outlook/homeandgarden/pets/articles/d82
http://voices.yahoo.com/what-if-re-sprayed-skunk-6299072.html
http://www.humanesociety.org/animals/skunks/tips/solving_problems_skunks.html
http://animals.howstuffworks.com/animal-facts/10-things-to-do-if-youve-been-skunked10.htm
http://www.psu.edu/dept/nkbiology/naturetrail/speciespages/stripedskunk.htm