Wetlands Mammals
Red Fox
basics
The red fox has orangish-red fur on its back, sides and head, and white fur under its
neck and on its chest. It has a long bushy tail tipped in white, prominent pointed black
ears and black legs and feet. It weighs 7-15 lbs., is 22”-27” long (w/o tail) and has a
shoulder ht. of 15”-16”.
They are solitary animals with home ranges that vary in size depending on the quality
of the habitat. In good areas ranges may be 2-5 sq. miles; in poorer habitats ranges are
larger, 8-20 sq. miles. During parts of the year adjacent ranges may overlap somewhat,
but parts may be regularly defended. Ranges are occupied by an adult male and one or
two adult females with their young. Animals remain in the same home range for life.
They live an average of 3 yrs. in the wild and 10 to 12 years in captivity.
Their top speed is about 30 mph, and they can leap as high as 6 ft.
Most red foxes that are taken by natural predators are young pups. Adult
red foxes may also be attacked by coyotes, wolves, or other predators, but
this is rarely in order to eat them. The most significant predators on red
foxes are humans.
habitat
The red fox makes its home along the edges of forests, in tilled fields and near marshes.
They prefer habitats with a diversity of vegetation types.
Except for breeding females, the fox doesn't usually use a den. Sometimes it will sleep
in the open, wrapping its bushy tail around its nose to stay warm. When it does use a
den, it will usually find an abandoned rabbit or marmot den instead of making its own.
adaptations
Activity: Mainly nocturnal or active at twilight, but will sometimes go out in the day.
Senses: A fox has excellent hearing and sense of smell, and depends on these two senses
in locating prey. It can hear a mouse squeak 100 ft. away and will dig in dirt or snow to
catch prey. They quickly see moving objects, but might not notice objects that are still.
Communication: Foxes communicate with each other with growls, yelps, and short
yapping barks. It also makes scent stations by urinating at various spots to tell foxes in
the area that another fox is present.
food
The red fox is an omnivore and its diet includes fruits, berries and grasses. It also eats
birds and small mammals like squirrels, rabbits and mice and invertebrates like crickets,
caterpillars, grasshoppers, beetles and crayfish. They also eat carrion. Red foxes store
extra food under leaves, snow or dirt and are very good at relocating these caches.
Foxes are quick, skillful hunters and can easily catch a dodging rabbit. The fox can also
creep silently toward a bird, rush up and pounce on it. They have a characteristic
manner of hunting mice. The fox stands motionless, listening and watching intently for
a mouse it has detected. It then leaps high and brings the forelimbs straight down
forcibly to pin the mouse to the ground. They eat between 1 and 2 lbs. of food each day.
breeding
The red fox is sexually mature at 10 months, mates annually, January through March
with a gestation period of 52 days. The average litter size is 5, weaned in 56–70 days.
The female will prepare multiple dens right after mating, using the extra dens if the
original den is disturbed. A fox den may be underground, in a cave, among rocks, or in
a hollow log or tree. Foxes will dig their own dens or modify burrows abandoned by
other animals. An underground den may be as long as 75 feet and have several
entrances. A main tunnel leads to several chambers that the animals use for nests and
for storing food. Two pairs of red foxes may share one burrow and the same den is
often used over a number of generations.
Young remain in the den for 4 to 5 weeks, where they are cared for and nursed by their
mother. Males and females, and sometimes their older offspring, cooperate to care for
the pups. The male brings the female food during the first few weeks.
The kits start playing outside the den when they are about a month old. The mother
begins feeding her kits regurgitated food, but eventually she will bring them live prey
to "play" with and eat. Playing with live prey helps the young kits develop the skills
they will need for hunting. The young remain with their parents at least until the fall of
the year they were born in and will sometimes remain longer, especially females. They
settle in areas as nearby as 6 miles and as far away as almost 250.
key facts
Weight: 7–15 lbs. Length w/o tail: 22–27 in. Shoulder height: 15–16 in.
Sharp Senses: Using their keen hearing and an excellent sense of smell
they can hear a mouse squeak over 100 feet away and will frequently dig
in the dirt or snow to catch prey.
Diet: As an omnivore the fox eats invertebrates, fruits and vegetation,
small birds and mammals. It eats between 1 and 2 lbs. each day.
Hunting: It has a distinctive hunting technique: freeze, listen, leap, and
pin down.
Breeding: The female prepares multiple dens after breeding but except for
raising young, foxes rarely use a den.
Communications: The fox makes urine scent stations to communicate
with other foxes.
Ecological Role: Red foxes help to control populations of their prey
animals, such as rodents and rabbits. They also disperse seeds by eating
fruit. In some areas where foxes had been killed off, rodents increased so
much that farmers brought in other foxes.
Coyote
basics
The coyote has a grizzled grey or reddish-grey coat with buff underparts, long, rusty or
yellowish legs, a bushy tail, arresting yellow eyes and prominent ears. It weighs 20-40
lbs. is 30-39” long w/o tail and has a shoulder height of 23-26”. They keep their young
in or near the den while they are young so that the pups aren’t killed by predators and
competitors such as wolves and mountain lions.
Their range is 12 miles in diameter around the den with travel along fixed
routes or trails; usually defended only during denning season.
They live 10 years in the wild, 18 years in captivity.
Top speed: Coyotes are capable of running at speeds up to 45 mph and
they can jump distances of up to 13 ft. They are good swimmers and
poor climbers.
habitat
Coyotes are adaptable utilizing a wide range of habitats including forests, clearcuts,
farms and woodlots and prefer habitats without wolves. Because of their tolerance for
human activities they are sometimes seen near farm buildings and at the edge of towns.
The typical den is a wide mouthed tunnel with several entrances, terminating in an
enlarged nesting area. Coyotes will dig their own burrows or enlarge those of other
mammals. Dens are used year after year.
The coyote was native only to the prairies and arid west but as settlers moved across the
country, altering the landscape and eliminating wolves, a new niche was opened up to
them. They now thrive in the Western Hemisphere from the Pacific to Atlantic Ocean.
adaptations
Activity: Coyotes are nocturnal but can occasionally be seen during daylight. They are
secretive, and near human habitations are active early in the morning and late evening.
Senses: They have acute hearing and sense of smell but their sight is less developed and
used primarily to note movement.
Communication: Coyotes use auditory, visual, olfactory and tactile signals to
communicate. They are the most vocal of all North American wild mammals, using 3
distinct calls, the squeak, distress call and howl call, all consisting of a quick series of
yelps, followed by a falsetto howl. Howling may act to announce where territories are
to other packs. Coyotes also howl when two or more members of a pack re-unite and to
announce to each other their location.
They use stumps, posts, bushes or rocks as "scent posts" on which they urinate and
defecate to mark territory.
food
Coyotes have versatile eating habits. They are essentially carnivorous; 90% of their diet
is mammalian. They eat small mammals and occasionally eat birds, snakes, large insects
and other large invertebrates. They prefer fresh meat, but eat large amounts of carrion.
Coyotes are less likely to form packs than are wolves. Hunting, which takes place
around the den, is done individually, in pairs or in family units depending on prey
availability.
Coyotes hunt animals in interesting ways. When on a "mousing" expedition, they
slowly stalk through the grass and sniff out the mouse. Suddenly, with all four legs held
stiffly together, the coyotes stiffen and pounce on the prey. Hunting deer, on the other
hand, calls for teamwork. Coyotes may take turns pursuing the deer until it tires, or
they may drive it towards a hidden member of the pack. They can run up to 40 mph.
Coyotes sometimes form "hunting partnerships" with badgers. The two move together,
using their keen sense of smell to locate burrowing rodents and badgers then dig them
up with their powerful claws. Both predators then share the proceeds. The average
distance covered in a night's hunting is 2½ miles.
Eating almost anything it can chew the coyote is an opportunistic and cunning hunter.
Part of what makes coyotes so successful at living in so many different places is the fact
that they will eat almost anything, including human trash and household pets in
suburban areas. Fruits and vegetables are a significant part of the diet of coyotes in the
fall and winter months.
breeding
Courtship lasts for approximately 2 to 3 months. Female coyotes are monoestrous and
are in heat for 2 to 5 days between late January and late March. Mating occurs within
these 3 months. Once the female chooses a partner, the mates may remain paired for a
number of years or for life.
Gestation lasts 60-63 days, with litter size 1-19 pups with 6 the average. The pups weigh
about 9 oz. and are born blind, limp-eared and pug-nosed. After 10 days their eyes
open, they weigh over a pound and their ears begin to erect in true coyote fashion.
21– 28 days after birth, the young emerge from the den, and by 35 days are fully
weaned. The parents feed them regurgitated food. The male pups leave the dens at 6- 9
months but the females usually stay with the parents and form the basis of the pack.
Adult size is reached at 9 to 12 months and sexual maturity is reached by 12 months.
key facts
Weight: 20-40 lbs. Length w/o tail: 30–39 in. Shoulder height: 23–26 in.
Diet: Coyotes eat mostly small mammals, but it depends on the season.
They rely on some carrion in winter.
Hunting: They use a very distinctive freeze-and-pounce mousing
technique.
Communication: They use auditory, visual, olfactory and tactile signals to
communicate and are the most vocal of all North American wild
mammals. They also, use "scent posts" to mark territory.
Senses: They have acute senses of hearing and smell.
Avian Conflicts: Coyotes will take birds on occasion, but generally favor
mammalian prey, so their impact is less than from other carnivores.
Ecological Role: Coyotes help keep small mammal populations in check,
such as mice and rabbits. If populations of these small mammals were
allowed to become too large it would result in habitat degradation.
Middle Dog: Halfway in size between wolves and foxes, coyotes don’t
usually get along with either because they overlap in food preferences.
Coyote are more numerous in the absence of wolves.
Raccoon
basics
Their color and weight vary with habitat and region. Their wt. is 12–31 lbs. and males
are usually heavier than females by 10 to 30%. Raccoons are stocky in build and their
Color ranges from grey to reddish brown to buff above, and black or grayish below. The
most prominent characteristics are the black mask outlined in white and the bushy tail
with 4-10 black or brown rings. Their tails comprise about 42%-52% of their total
length. The ears are small and the forepaws resemble slender human hands and make
the raccoon unusually dexterous. Both their forepaws and hindpaws have five toes.
Their home range is around 160 acres for males and 100 for females.
Home ranges are generally not exclusive, although some level of
territoriality has been recorded in western prairies where raccoon
densities are low, as is resource availability. Range diameters are typically
from 0.6 to 2 miles, but can be up to 6 miles in western areas.
Their common gait is a shuffle like walk but can reach speeds of 15 mph.
Raccoons don't travel any farther than necessary, traveling only far
enough to meet the demands of their appetites. They usually travel
between 0.5 and 1.5 mi. per night, with males traveling slightly farther
during fall, winter, and spring, and females traveling longer during
summer, when foraging with and for their young.
Raccoons may live up to 16 years in the wild, but most don't make it past
their second year. If they survive their youth, raccoons may live an
average of 5 years in the wild. The primary causes of death are humans,
(hunting, trapping, cars), and malnutrition.
Raccoons escape many predators by remaining inactive during the day in
a den. While active they remain alert and can be aggressive. They are
preyed on by large predators such as coyotes, wolves, large hawks and
owls. Their young may be taken by snakes as well.
Population densities vary widely with habitat type. In wet, lowland areas,
such as marshes, intertidal areas, and flood plains, densities averaged 5
per acre. Densities are generally less than half that in agricultural areas
and hardwood forests, higher than that in suburban areas. Rabies may
substantially impact population densities, with populations doubling in
density during times of low rabies incidence.
habitat
Raccoons are extremely adaptable and are found in many habitats but are most
common along stream edges, open forests and coastal marshes. They inhabit hollow
trees and logs and often use the ground burrows of other animals for raising their
young or for sleeping during the coldest part of the winter months.
They require ready access to water and prefer to live in moist woodland areas.
However, they can also be found in marshes, farmlands, suburban, and urban areas.
Raccoons prefer to build dens in trees, but also use burrows, caves, mines, deserted
buildings, barns, garages, rain sewers or houses.
adaptations
Activity: Raccoons are nocturnal and seldom active in the day. During very cold, snowy
times, raccoons have been seen sleeping for long periods at a time, but do not hibernate.
Their metabolic rate and temperature remains constant during these times and they live
off of their fat reserves, potentially losing as much as 50% of their body weight.
Primarily a solitary animal, the only real social groups raccoons form are that of mother
and young. Occasionally a male may stay with a female for a month prior to breeding
and until after the birth of their young.
Raccoons climb with great ease and are not bothered by a drop of 35-40 feet. As well as
being excellent climbers, raccoons are strong swimmers, although they may be reluctant
to do so. Without waterproof fur, swimming forces them to take on extra weight.
Senses: Raccoons have a highly developed tactile sense. Their human-like forepaws are
sensitive and enable the raccoon to handle and pry open prey and climb with ease. They
usually pick up food with their front paws before putting it in their mouth. With their
acute sense of hearing raccoons are also especially alert and have excellent night vision.
food
The raccoon is omnivorous and opportunistic. It feeds on wild grapes, cherries, apples,
berries, acorns, nuts, grubs, crickets and other insects, crayfish, frogs, fish, small
mammals, birds' eggs and nestlings. Raccoons consume more invertebrates than
vertebrates. In some habitats plants provide a larger percentage of a raccoon's diet than
animals do. Winter is the raccoon’s greatest enemy when food is scarce.
Raccoons have adapted to include trash and other food available in suburban and urban
areas in their diet. Some raccoons eat carrion from roadkilled animals. Raccoons travel
in straight lines between their dens and rich food patches.
Often seen washing their food, the raccoon is actually feeling for matter that should be
rejected as the wetting of the paws enhances its sense of feel.
breeding
The gestation period is 63 to 65 days. Sexual maturity often occurs in females before
they are one year old and in males at two years. Mating season is from February
through June, with most mating in March. Northern populations tend to breed earlier
than southern populations.
Raccoons generally have one litter per year. Born in April or May, litter sizes range from
3-7, but are typically 4. Young are born blind and helpless in a tree den, their eyes open
at 18-24 days of age, and they are weaned after 70 days, by late summer. At first the
mother carries them by the nape of the neck like a cat but by 20 weeks old the young
regularly forage with their mother at night and continue to stay in the den with her. The
young remain with her through their first winter, becoming independent the following
spring. Mothers and young often den nearby even after they have reached maturity.
During the mating season, raccoon males frequently expand their home ranges,
presumably to include the home ranges of more females as potential mates. Females are
sometimes found temporarily denning with males during the mating season. After
mating there is no association of males and females.
key facts
Weight: 12–31 lbs. Ave. Length: 16 in. plus tail of nearly same length.
Habitat: It is a common wetlands resident, using hollow trees and logs for
homes and ground burrows for raising young or for sleeping.
Diet: Omnivorous and opportunistic, they feed on fruit, seeds, nuts, grubs,
crickets and other insects, crayfish, frogs, fish, small mammals, birds' eggs
and nestlings. They consume more invertebrates than vertebrates.
Feeding: The raccoon picks up food with its front paws before putting it in
its mouth. They often seem to be washing their food as they feel for matter
that should be rejected; wetting of the paws enhances the tactile sense.
Activity\Senses: They have a good hearing and night vision and are most
active at night. They are good climbers and swimmers.
Predators: Their predators include coyotes, wolves, large hawks and owls.
Young are also taken by snakes.
Avian Conflicts: Raccoons and birds have interacted for millennia without
serious impact on either. What generally determines predator impact on
desired species such as birds is access and alternatives. Weather, climate,
restricted habitat and/or the absence of other predator food items can
shift the advantage to one or the other.
Striped Skunk
basics
The striped skunk weighs 4-9 lbs with a total length of 21-31”. Their fur is black with a
white stripe that begins as a triangular shape on the top of the head, forks into two
stripes that travel down the sides of the back, and usually merges again near the base of
the tail. Another white stripe runs from the base of the snout between the eyes and ends
on the forehead. Stripe width and length vary with each individual. The tail can be
striped but more often it is composed of both black and white hairs intermixed.
The striped skunk is about the size of a domestic cat, with a small head,
small ears, short legs, a long, fluffy tail and feet with five partially webbed
toes. Claws are longer on the front feet to aid in digging.
In the wild skunks may live to be 2 to 3 years old. Up to 90% of skunks die
in their first winter from predation, disease or starvation. In captivity they
have been known to survive for up to 15 years. Due to their offensive
odor skunks are rarely preyed on by other mammals but occasionally by
coyotes and badgers. They are eaten primarily by large birds that lack a
strong sense of smell, such as great-horned owls and red-tailed hawks.
habitat
The skunk prefers the desert, woodlands, grassy plains and suburbs and open areas
with a mixture of habitats such as woods, grasslands, and agricultural clearings and are
not usually found further than two miles from a water source. They are also often found
in suburban areas because of the abundance of buildings that provide them with cover.
adaptations
Their bold black & white fur pattern provides a memorable warning function to
dissuade would-be repeat offenders.
Activity: The skunk has perhaps the most widely known defense system of any
mammal, the scent-spraying mechanism. They don’t usually discharge the fetid, oily,
yellowish musk of their scent glands unless mortally threatened. When faced with
danger they first stomp their front feet as a warning, then arch the back and erect the
tail and hair. When mortally threatened they bend into a U-shape with both head and
rump facing the enemy. They then emit two streams of fluid from scent glands located
just inside the anus, which meet after traveling about a foot, finally spreading into a fine
spray that is accurate up to 15 feet. The spray often causes nausea and a fleeting loss of
vision as it burns the eyes and nasal cavities of the unfortunate target.
Striped skunks are nocturnal, sleeping during the day in underground burrows and
emerging around dusk to search for food. They prefer to use burrows made by other
animals of equal size or natural burrows under tree stumps or buildings. They use their
long front claws to build their own den if necessary. Although they do not hibernate,
during the lean winter months they may become temporarily dormant.
Both males and females undergo periods of inactivity from November until March.
Females often remain in their winter dens for the entire winter, but males usually
emerge during mild temperature periods to feed. Winter dens usually consist of six
females and their young. One male sometimes occupies a den with females, but usually
lives alone in its own den.
Senses/Communication: Skunks have a good sense of hearing, but their vision is poor.
They use scent marking to communicate presence and reproductive state to other
skunks. They also communicate visually, by raising their fur and changing posture.
They are mostly silent, but do make a variety of sounds such as churring, hisses, and
screams.
food
The skunk is a true omnivore, and eats insects, small mammals, fish, crustaceans, the
eggs of ground nesting birds, amphibians, fruits, grasses, leaves, buds, grains, nuts, and
carrion. Insects make up approximately 70% of their diet but skunks are opportunistic
and diet changes depending on the time of year and available resources. They will
scratch on hives to encourage the bees to emerge, and then kill them as they do.
breeding
In mid May 2–11 young are born, with an average of 7.
Females are monestrous, but they occasionally can have a second estrous if the first
pregnancy is unsuccessful. Mating takes place from mid-February until mid-March. The
gestation period is 63-66 days, with a brief delayed implantation probably involved. At
birth, baby striped skunks are blind, deaf, and extremely immature. They nurse for
about a month and a half in the mother's den. Fully weaned, the young then follow the
mother about, finally breaking from the family about a year after reaching adult size. M.
Males provide no parental care and are typically polygamous and solitary. Males and
females do not associate beyond the few days required for fertilization.
key facts
Weight: 4–9 lbs. Total length: 21–31 in.
Lifespan: In the wild skunks may live to be 2 to 3 years old. Up to 90% of
skunks die in their first winter from predation, disease or starvation.
Defense: One of the most widely known defense systems of any mammal,
the scent-spraying mechanism.
Senses: Strongest sense is hearing.
Diet: A true omnivore, it eats a vast assortment of insects, small mammals,
fish, crustaceans, the eggs of ground nesting birds, amphibians, fruits,
grasses, leaves, buds, grains, nuts, and carrion. Insects make up
approximately 70% of their diet and they will scratch on hives to
encourage the bees to emerge, and then kill them as they do.
Predators: Mostly large birds that lack a strong sense of smell, such as
great-horned owls and red-tailed hawks. Their offensive odor causes most
mammals to avoid skunks. Their bold black & white fur pattern helps
attackers remember negative experiences.
Winter: They do not hibernate, but go into periods of torpor.
Avian Conflicts: Skunks and birds have interacted for millennia without
serious impact on either.
Ecological Role: They help control insect populations.
Long-tailed Weasel
basics
The long-tailed and short-tailed weasels occur in northern Utah, the former being the
larger of the two. The short-tailed weasel, also called ermine, generally inhabits forests
and their borders. Long-tailed weasels are more common in open habitat like marshes.
The long-tailed weasel weighs 6-16 oz., is 8-15” w/o the tail and the males are
considerably larger than females. They have a long slender body, short legs and long
bushy tails that are about 50% of their total body length. Their head is small and narrow
and they have long whiskers. The fur is composed of short, soft underfur covered by
shiny guard hair. They are cinnamon brown in color with white under parts that have a
yellow tinge. The coat of animals in northern populations is white in the winter and
brown in the summer, while those in southern populations are brown year round.
The home ranges of long-tailed weasels can vary from 25-400 acres
depending on food supplies. Long-tailed weasels are not social animals;
the sexes live apart from each other except during the mating season. One
male's home range may overlap several female home ranges, but home
ranges of adults of the same sex never overlap. Weasels exhibit very
aggressive behavior to intruders of their home ranges.
Feisty and aggressive, they will threaten animals much larger than
themselves. They may be preyed upon by larger animals, like large owls,
coyotes, or large snakes and are especially vulnerable to predators at a
young age. Many die before reaching one year old, however once they
reach adulthood, they may live for several years.
habitat
This weasel is most common in open habitats, ranging from marshes and crop fields to
small wooded areas and suburban areas. They are not found in deserts or dense forests.
Their dens and nests are in hollow logs, rock piles, under tree stumps and barns.
Sometimes instead of building a new nest, they take over the burrow of one of their
prey & line their nest chambers with grass or fur and feathers of the previous occupant.
adaptations
Appearance: Twice a year these slender bodied weasels shed their fur, once in the
spring and again in the fall. This process is controlled by photoperiod.
Activity: Long-tailed weasels are quick, agile, and alert animals. They are good climbers
and swimmers. While they can be active during the day, they are more active at night.
Weasels bound or lope with the back arched and tail held straight out or slightly higher
than the plane of the back. They swim well and climb trees easily. Their small girth (1 to
1 1/2 inches) enables it to easily invade rock crevices and mouse and squirrel burrows.
Senses/Defenses: Long-tailed weasels have well-developed senses of sight, hearing,
and smell, which allows them to be efficient and sensitive predators. Weasels, like
skunks, discharge a foul-smelling liquid called musk when they are threatened or
attacked.
Communication: Long-tailed weasels communicate among themselves with visual,
sound, and scent cues. Females emit an attractive scent when they are ready to mate.
Body language and sounds are used to communicate when weasels confront each other.
A loud, harsh chirp or a screech can be heard when a weasel is disturbed or ready to
attack. A low trill often signals a friendly meeting between male and female. A trill also
helps a female to call her young. Babies make high-pitched squeaks and at about four
weeks it gets lower-pitched & raspier, eventually reaching a chirp similar to the adults.
food
Mammals are the food of choice: mice, rats, voles, squirrels, chipmunks, shrews, moles
and rabbits. Less common foods include birds, bird eggs, snakes, lizards, frogs,
earthworms, insects, fruits and berries.
Long-tailed weasels hunt their prey by picking up a scent or sound, then follow the
animal and make a quick attack. They kill their prey by biting the base of the skull. They
are very strong, able at times to take prey more than three times their own weight.
They follow regular hunting routes, starting and ending at the den, covering only parts
of their home ranges during a single night. In a night they may go less than one tenth of
a mile up to 3½ miles with males going further than females. Females have better
success in hunting small rodents because their bodies can fit inside the small rodent
burrows. Males often pursue larger animals, such as squirrels and rabbits.
breeding
Long-tailed weasels have only one litter per year. Females mate in their first summer,
but males wait until the following spring. They mate in July or August. The fertilized
eggs develop for eight days, and then enter an extended dormant period. About 7½
months later, the eggs attach to the wall of the uterus and resume development. The
young are born 23 to 27 days later, usually during April or May. Litter sizes vary from 1
to 9 and average 4 to 5 young.
At birth young weasels weigh about 0.1 oz. (3 grams, or the weight of a dime). They are
pink with wrinkled skin and white fur. At fourteen days, the white hair begins to
thicken, and size differentiation makes it easy to tell males from females. At 36 days
young weasels are weaned and can eat food brought back to the nest by the mother.
They learn how to kill prey from the mother and by 56 days old they are able to kill
prey on their own. Young long-tailed weasels begin hunting with their mother at 6 to 7
weeks and are ready to leave her at about 11 to 12 weeks.
key facts
Weight: 6–16 oz. Length w/o tail: 8–15 inches. Males are considerably
larger than females.
Appearance: The weasel has a long slender body, short legs and a long
bushy tail. It’s cinnamon brown with yellow-tinged white under parts.
Diet: Small mammals are the food of choice—mice, rats, voles, squirrels,
chipmunks, shrews, moles and rabbits. Less common foods: birds, bird
eggs, snakes, lizards, frogs, earthworms, insects, fruits and berries. Male-
female size difference helps them reduce reliance on the same prey items.
Color Changer: They shed their fur to change from brown to white,
summer to winter, then back again, triggered by day length. They evolved
as a benefit to warmth (hollow white hair), but also aids in camouflage.
Behavior: Ounce for ounce, weasels are among the world’s most
impressive predators. They resemble hyperactive tubes of muscle ever
alert to pounce upon an unsuspecting small mammal. They are amazingly
strong for their size, able to take prey more than three times their own
weight. They kill with a quick bite to the base of the skull.
Shelter: Hollow logs, tree stumps, rock piles or under barns. Sometimes
instead of building a new nest, they take over the burrow of a prey
mammal, lining their nest chambers with the victim’s fur.
Predators: Large owls, coyotes or large snakes are their predators. They
are especially vulnerable when they are young.
Ecological Role: Weasels will occasionally take birds but their impact is
less than from other carnivores. Long-tailed weasels help to control the of
rodent and rabbit populations.
Vagrant Shrew
basics
The world’s smallest mammal is a shrew, of which there are over 300 species
worldwide. Most are very small, with the smallest adult weighing only 2-3 grams (one-
tenth of an ounce). Some shrews are poisonous, allowing them to hunt and kill larger
prey, including small vertebrates. Most shrews seem to prefer moist microhabitats,
although a few species are found in deserts.
A few kinds of shrews are aquatic, including the water shrew that is also found here. It
is well adapted to swimming and catching aquatic invertebrates and small fish. They
have long, bristly hairs between their toes and along the sides of their feet, which aid
them in swimming by increasing the surface area of the feet. These hairs also can hold
air bubbles, allowing the shrew to actually run across the surface of the water!
While the information below is specific to the vagrant shrew, much is applicable to
other species.
The vagrant shrew weighs
1
16
–
1
4
oz. with a total length of 3.75–4.75 in.
(Tail: 1.25–2 in.) It gets its name from its extraordinary activity in pursuit
of food rather than to its wanderings, which are no greater than those of
other shrews.
In summer it is brownish to grayish above, grayish tinged with brown or
red below. In winter, entirely grayish or blackish. Its long tail is uniform in
color or grading to paler below.
Breeding home ranges average 0.82 acre and non-breeding home ranges
average 0.26 acre. Adults are solitary except for breeding season, when
there is extensive home range overlap. Adults begin defending their home
ranges from other adults in late summer and continue to do so until the
next mating season. Predators include snakes and barn owls.
habitat
They are found in open areas, woodlands and forests, prefer dense litter or ground
cover, use vole runways, and prefer patchy, open areas with wet microhabitats such as
damp meadows and stream banks. Rarely are they found more than 600 ft. from water.
adaptations
Physical: The pointed shape of their snout helps them burrow into the ground as they
look for prey items such as grubs. Their small size results in a large amount of surface
exposed, relative to its volume, which results in significant heat loss and a voracious
appetite to replenish the lost energy. Its heart can beat up to 1,000 times per minute.
Their eyes are tiny and their main senses are probably touch, hearing, and smell.
Activity: Although active day or night, most activity is nocturnal. It spends much of its
time in voles’ runways avoiding predation and seeking food. It forages under litter on
moist surfaces, underground, and in moist accumulations of dead plant material.
food
Shrews have a high metabolic rate and consequently a voracious appetite. On average,
shrews must eat every three hours, and so are active throughout the day and night,
feeding primarily on invertebrates like insects and their larvae, caterpillars, centipedes,
worms, snails, slugs, and spiders. They also eat fungi, small mammals, roots, young
shoots, and probably seeds.
breeding
The shrew makes a nest of dry grass, moss, or other materials under logs, roots, or
dense vegetation. After a 20-day gestation period, most young are born from March to
May but there may be a second peak of births in August and September. Litter size
ranges 2-9 with 6 the average, and there are 1 or 2, rarely, 3 litters per year. The young
are weaned 16-20 days after birth. Females may breed in their first year, and the
maximum lifespan is about 16 months. Most shrews do not live to breed a second year.
key facts
Weight:
1
16
–
1
4
oz. Total Length: 3.75–4.75 in. (Tail: 1.25–2 in.)
World Record: Shrews are the world’s smallest mammals. The vagrant
shrew weighs about the same as a quarter.
Lifespan/Senses: They live about 16 months and most do not live to breed
a 2nd year. Their senses are touch, hearing and smell…eyes are tiny.
Habitat/Predators: Wetlands are perfect for shrews—lots of insects to eat
and places to hide. They stay close to water, foraging under litter on moist
surfaces, underground, and in moist accumulations of dead plant
material; use vole runways. Predators include snakes and barn owls.
Diet: They eat mostly invertebrates—insects and their larvae, caterpillars,
centipedes, worms, snails, slugs, and spiders. Its small body causes it to
lose heat fast, and it has a metabolism to keep up: It must eat something
every 3 hours—the same or more than its own weight each day!—and its
heart beats up to 1,000 times per minute.
Meadow Vole
basics
Voles are thickset, short-tailed, short-eared versions of mice, to which they are closely
related. In Northern Utah there are four major groupings: red-backed, heather, meadow
and sagebrush voles. The information below is based mostly on the meadow vole, but is
variously applicable to the other species as well.
The meadow vole weighs 1.2–2.3 oz. and is 5½–7¾ inches long including its tail (1¼ –
2½ in.). Its back color ranges from yellowish to reddish brown, sprinkled with black, to
blackish brown. The abdomen is grey or white and may be tinged with light brown. Its
winter fur is duller and grayer and there is no difference in size or color by to sex.
Females are territorial, and males have overlapping home ranges about three times
larger than those of females. Female territories are actively defended and when more
than one female occurs within a territory it is probably a mother-daughter relationship.
The mother seems to prevent these offspring from breeding, although how is unknown.
Meadow voles are short-lived, rarely living for longer than one year in the
wild. They are aggressive and will attack when cornered or captured.
Their predators are owls and other birds of prey, snakes, foxes & weasels.
Meadow voles are aggressive and will attack if cornered or captured. They
take refuge from predators in their system of burrows and grass tunnels.
habitat
They live in meadows, lowland fields, grassy marshes, near rivers & lakes and they are
sometimes found in flooded marshes, high grasslands near water, or grassy open
woodland. Meadow voles seem capable of excluding red-backed voles and mice from
their preferred grasslands.
A common sign of the meadow vole is the piles of grass cuttings that it leaves in its
runways, located within dense vegetation.
adaptations
Activity: The meadow vole is active at all times of the day, but tends to be more
nocturnal during the summer and diurnal during the winter. During cold winter
months communal nesting can occur among non-overlapping maternal families
consisting of non-reproducing individuals of mixed sex and age groups.
The meadow vole makes extensive runways through vegetation where they deposit
feces and food refuse. They are proficient diggers and swimmers.
Senses/ Communication: Meadow voles have keen hearing and a good sense of smell.
Vocalizations are primarily used in defensive situations.
Food
From May until August voles feed mainly on fresh grasses, sedges, and succulent
vegetation. In the fall they switch to grains and seeds, and during the winter they have
been known to feed on the bark and roots of shrubs and small trees. These voles will
also eat tubers and bulbs when available. When they overlap the range of cranberries,
meadow voles feed on them extensively. They also eat other types of fruit.
Meadow voles do eat flesh and are cannibalistic, especially on newborn young. They
don’t show much storage behavior, but sometimes make small caches of tubers in fall.
They are voracious eaters, consuming close to 60% of their body weight daily. When
eating, these animals sit up and will stand to gnaw bark or a grain stalk.
breeding
Mating is promiscuous. Gestation is 21 days. The size of the litter varying from 1–11,
with an average of 4–6, is correlated with the size of the female, with younger females
giving birth to smaller litters. In their first month 90% perish. Those born in the spring
reach adult size in 3 months; those born later do so after winter.
They breed all year round with March through November being the main breeding
season. Breeding is virtually continuous and the female will mate immediately after
giving birth. First mating in females occurs when they are about half grown at an age of
25 days. Males mate when they reach the age of about 45 days.
Baby voles are born helpless, but grow quickly. Females care for and nurse their young
in the nest until they are weaned at two weeks old. Soon after weaning the young
disperse from their mother's home range.
key facts
Weight: 1.2–2.3 oz. Length: 5½–7¾ inches, including tail (1¼ – 2½ in.) The
meadow vole is larger than most other vole species.
Habitat: They’re more common in meadows than in marshes, since their
preferred food is fresh grasses and sedges, or their seeds. They eat close to
60% of their body weight daily.
Habits/Senses: Makes extensive runways through vegetation and are
proficient diggers and swimmers. They have a keen sense of smell and
hearing.
Prolific/ Short Lifespan: A vole female can give birth to as many as 40
young in a year. They rarely live longer than one year in the wild.
Predators: Owls, other birds of prey, snakes, foxes and weasels are its
predators. These voles are aggressive and will attack when cornered or
captured, and hide from predators in their system of burrows and tunnels.
Ecological Role: While to us they look similar to mice, there are more
kinds of voles, they are more abundant and their role in the ecosystem is
far greater. Many predator species rely on voles to make up a significant
portion of their diet, especially owls, small hawks and falcons. In addition,
meadow voles consume large quantities of grass and recycle the nutrients
held in the grass through their droppings. They also help to aerate and
turn the soil through their digging activities.
Muskrat
basics
A muskrat’s average weight is 2.5 lbs. and their average length is 12.5 inches, plus a 9.5
in. tail. They have large, robust bodies with a flat and scaly tail. Their heads are very
large, their ears are almost invisible underneath the fur, and their whiskers are medium
size. Muskrats have short legs and big feet. Adult muskrats have glossy upperparts that
are dark brown, darker in winter and paler in the summer.
Muskrats are arranged in large family groups and live in definite territories. If the
conditions are overcrowded, the females will kick their offspring out of the group.
Muskrats continue to live in large groups even when fighting and cannibalism occur in
high rates.
Their name derives from the distinctive odor from their musk glands,
used to communicate with others of their species.
Although muskrats have been known to live to 10 years old in captivity,
they probably live about 3 years in the wild.
Their predators are mink, raccoons, otters, coyotes, barn owls, barred
owls, northern harriers, bald eagles and several hawk species.
Muskrats are excellent swimmers and can evade many predators by
escaping into water or into their burrows and nests.
habitat
Muskrats are found in wet environments, favoring locations with 4-6 ft. of water. While
muskrats are found in ponds, lakes, and swamps, their favorite locations are marshes,
where the water level stays constant. Marshes also provide the best vegetation.
Muskrats find shelter in bank burrows, tunnels excavated in a bank, and their
distinctive nests. The nests of the muskrats are formed by piles of vegetation placed on
top of a good base, for example a tree stump, generally in 15 to 40 inches of water.
adaptations
Physical: The back feet are slightly webbed for swimming, the tail is flattened to serve
as a rudder and the underfur is waterproof and traps air bubbles for buoyancy and
insulation. They have a special adaptation called regional heterothermia, which
regulates the flow of blood to the feet and tail, allowing these structures to be cooler
than the body core.
Activity: Muskrats are active at all times of the day but most active from mid-afternoon
until just after dusk. They construct lodges of vegetation or excavate bank dens to
protect them from the elements and predators. They are good swimmers and can stay
underwater for 12–17 minutes but move relatively slowly on land.
Senses: Muskrats have poorly developed senses of sight, hearing, and smell and are
affected by quick changes in temperature. Dry, hot weather is especially bad for them.
Communication: Muskrats communicate by a secretion of musk from their glands. This
scent also serves to warn intruders. They can also vocalize with squeaks and squeals.
food
In summer they eat the roots of aquatic plants, including cattails, and in winter they
swim under the surface ice to get to plant foods. In winter they also make “pushups” of
aquatic vegetation that they shove up through cracks in the ice to feed upon.
Muskrats consume about one-third of their weight every day. Their digestive system is
designed for green vegetation. Muskrats are mainly vegetarians but will eat clams,
crayfish, turtles and fish as well.
breeding
Northern populations usually breed March to August, sometimes resulting in two or
even three litters. The gestation period is 29-30 days and the litter size averages 6 or 7.
Young are born in a grass-lined nest. When born, the muskrat has short dark fur, closed
eyes, and weighs around ¾ oz. They are able to swim at 10 days and by 21 days can eat
green vegetation. In 30 days muskrats gain their independence and will reach adult size
in 200 days. Most muskrats wait to breed in their second year.
Young are cared for and nursed by their mothers in the nest until they are about 2
weeks old, when they begin to swim and eat vegetation. They are fully weaned by 3 to 4
weeks old and leave their mother's home range after their first winter, usually when
they are less than a year old.
key facts
Ave. weight: 2.5 lbs. Average length: 12.5 inches, plus a 9.5 in. tail.
Features: Large, well-insulated underfur is waterproof and traps air
bubbles for buoyancy; webbed feet for swimming with flat, hairless tail
used as a rudder.
Habitat: Well-suited for the food and cover of wetland marshes. For
shelter they use bank burrows, tunnels excavated in a bank, and their
distinctive nests which are formed by piled vegetation.
Habits: They are excellent swimmers and evade predators by escaping
into water or into their burrows and nests. They can remain under water
for up to 17 minutes.
Food: Mainly leaves and roots of aquatic plants, including cattails, but
also clams, crayfish, turtles and fish. In winter, they swim under the
surface ice to get to plant foods and make “pushups” of aquatic vegetation
to feed upon.
Predators: Mink, raccoons, otters, coyotes, barn owls, barred owls,
northern harriers, bald eagles and several hawk species.
Ecological Role: Muskrats are abundant in areas of good habitat, making
them important prey animals for predator populations. By grazing on
vegetation, muskrats influence the make-up of local plant communities.
