Virginia Opossum (Didelphis virginiana)

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Virginia Opossum (Didelphis virginiana) ORDER: Didelphimorphia FAMILY: Didelphidae FIELD GUIDE TO NORTH AMERICAN MAMMALS The Virginia opossum, the only marsupial found north of Mexico, is an

They are active at night, year round: in freezing weather, an unlucky opossum can lose its ear tips and the end of its tail to frostbite.

1 Virginia Opossum (Didelphis virginiana) ORDER: Didelphimorphia FAMILY: Didelphidae FIELD GUIDE TO NORTH AMERICAN MAMMALS The Virginia opossum, the only marsupial found north of Mexico, is an adaptable omnivore at home on the ground and in the trees. Opossums prefer forested habitats, but they are quite successful even in urban areas. They are active at night, year round: in freezing weather, an unlucky opossum can lose its ear tips and the end of its tail to frostbite. Like all marsupials, opossums give birth to tiny, undeveloped young. The embryos develop in the mother's womb for less than two weeks, then the newborn opossums crawl from the birth canal to the mother's pouch, where they fasten tight to a nipple. They stay there, attached to the nipple, for 55 or 60 days. A female opossum usually has 13 nipples, and litters are usually smaller than that, but a baby that cannot attach to a nipple dies. After about 60 days the young opossums leave the pouch, but they stay close to their mother sometimes riding on her back when they are out at night and nurse for another month or more. Credit: painting by Todd Zalewski from Kays and Wilson's Opossums, Possum Males are slightly larger and much heavier than females, with larger canine teeth. Average: 740 mm Range: mm Range: kg males, kg females 1

FIELD GUIDE TO NORTH AMERICAN MAMMALS Nine banded Armadillo (Dasypus novemcinctus) ORDER: Xenarthra FAMILY: Dasypodidae The tank like Nine banded Armadillo's range has greatly expanded northward in

Armadillos are typically active at night or twilight. They shuffle along slowly, using their sense of smell to find food mostly insects, and occasionally worms, snails, eggs, amphibians, and berries.

2 FIELD GUIDE TO NORTH AMERICAN MAMMALS Nine banded Armadillo (Dasypus novemcinctus) ORDER: Xenarthra FAMILY: Dasypodidae The tank like Nine banded Armadillo's range has greatly expanded northward in the last 100 years. In the mid 1800s it was found only as far north as southern Texas; by the 1970s it lived in Oklahoma, Kansas, Missouri and Tennessee; now it s also on the East Coast. Armadillos are typically active at night or twilight. They shuffle along slowly, using their sense of smell to find food mostly insects, and occasionally worms, snails, eggs, amphibians, and berries. They root and dig with their nose and powerful forefeet to unearth insects or build a burrow. They always give birth to identical, same sex quadruplets that develop from a single fertilized egg. Only two mammals are known to get a disease called leprosy: humans and armadillos. This has made armadillos important in medical research. Credit: painting by Todd Zalewski from Kays and Wilson's Long nosed Armadillo Males are heavier than females. Range: mm Range: kg males, kg females 1

FIELD GUIDE TO NORTH AMERICAN MAMMALS Southern Short tailed Shrew (Blarina carolinensis) ORDER: Insectivora FAMILY: Soricidae The Southern Short tailed Shrew is a highly active, primarily nocturnal

These shrews eat snails, butterfly and beetle larvae, ants, and small soil living invertebrates.

3 FIELD GUIDE TO NORTH AMERICAN MAMMALS Southern Short tailed Shrew (Blarina carolinensis) ORDER: Insectivora FAMILY: Soricidae The Southern Short tailed Shrew is a highly active, primarily nocturnal predator. It is most common in moist, well drained hardwood forests or pine stands, especially where deep organic litter provides easy burrowing for shelter and food. These shrews eat snails, butterfly and beetle larvae, ants, and small soil living invertebrates. The Southern Short tailed Shrew is preyed upon by many species, ranging from snakes to hawks to foxes and coyotes. Barn owls also eat these small animals, and regurgitate their skeletal and fur remains in the form of pellets; the pellets are a rich source of information for field biologists. This species is so similar to other short tailed shrews that even experts cannot distinguish them easily, and must rely on a laboratory count of chromosomes to tell them apart. Blarina sp. summer coat Credit: painting by Nancy Halliday from Kays and Wilson's None Average: 90 mm Range: mm Range: g 1

Least Shrew (Cryptotis parva) FIELD GUIDE TO NORTH AMERICAN MAMMALS ORDER: Insectivora FAMILY: Soricidae Least Shrews have a repertoire of tiny calls, audible to human ears up to a distance of only

Weighing in at only a few grams, this shrew is remarkably adaptable, as its extensive north to south distribution attests.

4 Least Shrew (Cryptotis parva) FIELD GUIDE TO NORTH AMERICAN MAMMALS ORDER: Insectivora FAMILY: Soricidae Least Shrews have a repertoire of tiny calls, audible to human ears up to a distance of only 20 inches or so. Nests are of leaves or grasses in some hidden place, such as on the ground under a cabbage palm leaf or in brush. Weighing in at only a few grams, this shrew is remarkably adaptable, as its extensive north to south distribution attests. From southern New England to northern Panama, the Least Shrew inhabits grassy fields, marshes, and woodland habitats. Cryptotis parva summer Credit: painting by Nancy Halliday from Kays and Wilson's Small Short tailed Shrew, Little Short tailed Shrew, Bee Shrew None Average: 75 mm Range: mm Range: 3 10 g 2

FIELD GUIDE TO NORTH AMERICAN MAMMALS Crawford's Gray Shrew (Notiosorex crawfordi) ORDER: Insectivora FAMILY: Soricidae These shrews live in deserts, but they seek out moister microhabitats within

Captive individuals ate a variety of insects, including cockroaches, beetles, mealworms, and moths, and also accepted carrion.

5 FIELD GUIDE TO NORTH AMERICAN MAMMALS Crawford's Gray Shrew (Notiosorex crawfordi) ORDER: Insectivora FAMILY: Soricidae These shrews live in deserts, but they seek out moister microhabitats within them, such as brushpiles or fallen logs. They have been found in beehives, and their tiny, golfball sized nests have been found in dens built by and sometimes still occupied by woodrats. Captive individuals ate a variety of insects, including cockroaches, beetles, mealworms, and moths, and also accepted carrion. They would not attack live rodents, or eat salamanders, earthworms, or scorpions. Crawford s Gray Shrews give birth to litters of 3 to 5 relatively helpless, but rapidly maturing, young, which leave the nest by six weeks of age. Notiosorex crawfordii Crawford's Gray Shrew Credit: painting by Nancy Halliday from Kays and Wilson's Gray Shrew, Desert Shrew Average: 87.6 mm Range: mm Average: 4.3 g Range: g 3

Eastern Mole (Scalopus aquaticus) ORDER: Insectivora FAMILY: Talpidae FIELD GUIDE TO NORTH AMERICAN MAMMALS Eastern Moles have the widest distribution of any North American mole, and are common

They avoid areas that are too wet or too dry.

6 Eastern Mole (Scalopus aquaticus) ORDER: Insectivora FAMILY: Talpidae FIELD GUIDE TO NORTH AMERICAN MAMMALS Eastern Moles have the widest distribution of any North American mole, and are common throughout most of the eastern United States where soils are favorable. They prefer moist loamy or sandy soils and are scarce or absent in heavy clay, stony, or gravelly soils. They avoid areas that are too wet or too dry. Well adapted to a fossorial (underground) life, the eastern mole has short, fine fur that can lie flat facing forward or backward, depending on whether the animal is moving forward or backward through a tunnel. Its eyes are covered by skin, there are no external ears; and the mole's body is streamlined and powerful, equipped with broad side facing hands for digging. Scalopus aquaticus northern form Credit: painting by Nancy Halliday from Kays and Wilson's Topos Males are larger than females. Average: 151 mm males; 149 mm females Range: mm males; mm females Average: 90 g males; 70 g females Range: g males; g females 4

Then it migrates southward into Mexico, where it lives in pine oak forests and deserts. It may be the main pollinator of a plant that has economic value in Mexico, the pulque plant.

7 FIELD GUIDE TO NORTH AMERICAN MAMMALS Mexican Long nosed Bat (Leptonycteris nivalis) FAMILY: Phyllostomidae Conservation Status: Endangered. The Mexican long nosed bat feeds mainly on the nectar and pollen of agaves, and is found in Texas in June and July, when the plants are in bloom there. Then it migrates southward into Mexico, where it lives in pine oak forests and deserts. It may be the main pollinator of a plant that has economic value in Mexico, the pulque plant. Little is known about the bat's pattern of reproduction. Nursing females and juvenile bats have been seen in Texas in June and July. Big Long nosed Bat None Average: 83 mm Range: mm Mexican long tongued bat (Choeronycteris mexicana) on left, and Mexican long nosed bat (Leptonycteris nivalis) on right Range: g 2

FIELD GUIDE TO NORTH AMERICAN MAMMALS Townsend's Big eared Bat (Corynorhinus townsendii) FAMILY: Vespertilionidae Conservation Status: Vulnerable.

For females, foraging increases during pregnancy and lactation, from one or two foraging bouts per night to three, and the distance traveled also increases, from 1.0 km to more than 4.0 km per night.

8 FIELD GUIDE TO NORTH AMERICAN MAMMALS Townsend's Big eared Bat (Corynorhinus townsendii) FAMILY: Vespertilionidae Conservation Status: Vulnerable. Sporting prominent ears that look almost like wings, Townsend s big eared bat largely preys on moths over open pasture and forest canopy. For females, foraging increases during pregnancy and lactation, from one or two foraging bouts per night to three, and the distance traveled also increases, from 1.0 km to more than 4.0 km per night. Females form maternity groups in the spring, in caves and shelters, where they give birth to a single pup. In addition to winter hibernation, these bats also experience daily periods of torpor during cooler weather, a sleeplike state of reduced motor and metabolic activity. Townsend s big eared bat occurs in the western United States, northward to British Columbia, as far east as the Rocky Mountain States from Idaho to Texas, including Kansas and Oklahoma, and there are also populations in Arkansas, Missouri, Kentucky, Virginia, and West Virginia. Western Long eared Bat, Western Big eared Bat, Western Lump nosed Bat, Mule eared Bat Females are larger than males. Range: mm Range: 9 12 g 3

Red Bat (Lasiurus borealis) FIELD GUIDE TO NORTH AMERICAN MAMMALS FAMILY: Vespertilionidae Common and widespread from far southern Canada throughout most of the United States and Mexico, and farther

It is remarkable for its richly colored reddish pelage, with the male brighter than the female. Although the red bat is solitary, it migrates in groups.

9 Red Bat (Lasiurus borealis) FIELD GUIDE TO NORTH AMERICAN MAMMALS FAMILY: Vespertilionidae Common and widespread from far southern Canada throughout most of the United States and Mexico, and farther south through Central America and into South America, the red bat requires trees and shrubs for roosting. It is remarkable for its richly colored reddish pelage, with the male brighter than the female. Although the red bat is solitary, it migrates in groups. Females often give birth to twins and sometimes to quadruplets. The young are born hairless, with eyes closed, and weigh only 0.5 g, but by 3 6 weeks they are covered with fur, have their eyes open, are half their mother's weight, and can fly. Lasiurus borealis female (left) and male (right) Females are larger than males. Average: mm Range: mm Range: 7 16 g 4

Hoary Bat (Lasiurus cinereus) FIELD GUIDE TO NORTH AMERICAN MAMMALS FAMILY: Vespertilionidae Hoary bats are found from northern Canada all the way to

Their frosted, or hoary, look comes from a tinge of white over their grayish brown fur.

10 Hoary Bat (Lasiurus cinereus) FIELD GUIDE TO NORTH AMERICAN MAMMALS FAMILY: Vespertilionidae Hoary bats are found from northern Canada all the way to Guatemala, and also in South America and Hawaii. They are solitary and roost in trees. Their frosted, or hoary, look comes from a tinge of white over their grayish brown fur. Their flight is distinctively fast and direct and can be used as an identifying trait. Hoary bats eat moths, beetles, grasshoppers, wasps, and dragonflies. Females are larger than males. Average: 80.5 mm males; 83.6 mm females Range: mm Range: g 5

FIELD GUIDE TO NORTH AMERICAN MAMMALS Southern Yellow Bat (Lasiurus ega) FAMILY: Vespertilionidae A strong flier with yellowish fur, the southern yellow bat is a lowland species, adapted to both dry

Very few species of bats have more than one or two young at a time, and most have just two nipples, but some bats in the genus Lasiurus have four nipples and can have triplets or quadruplets.

11 FIELD GUIDE TO NORTH AMERICAN MAMMALS Southern Yellow Bat (Lasiurus ega) FAMILY: Vespertilionidae A strong flier with yellowish fur, the southern yellow bat is a lowland species, adapted to both dry and wet habitats. It roosts in trees, particularly palms. These bats are often seen hunting over water, including over swimming pools. Very few species of bats have more than one or two young at a time, and most have just two nipples, but some bats in the genus Lasiurus have four nipples and can have triplets or quadruplets. Southern yellow bats most often have triplets. The young bats nurse for about two months before they are able to fly and forage for themselves. Western Yellow Bat, Tropical Yellow Bat Lasiurus ega inset shows white hairs on underside of wing Females are larger than males. Average: mm Range: mm Average: 11.9 g Range: g 6

FIELD GUIDE TO NORTH AMERICAN MAMMALS Northern Yellow Bat (Lasiurus intermedius) FAMILY: Vespertilionidae Clumps of Spanish moss make good daytime roosting places for northern yellow bats.

They are seldom found roosting in houses or other manmade structures.

12 FIELD GUIDE TO NORTH AMERICAN MAMMALS Northern Yellow Bat (Lasiurus intermedius) FAMILY: Vespertilionidae Clumps of Spanish moss make good daytime roosting places for northern yellow bats. Small groups of males or slightly larger groups of females are often found roosting together in forested areas near a permanent source of water. They are seldom found roosting in houses or other manmade structures. They feed over open spaces: they are seen over golf courses, beaches, and along the edges of ponds, hunting for mosquitoes, flies, and other insect prey. Barn owls are known to prey on them. Unlike most other Lasiurus bats, they have only two nipples, and if a female gives birth to more than two offspring, usually only two survive. Young are born in May or June and are flying by June or July. Eastern Yellow Bat, Florida Yellow Bat, Greater Yellow Bat, Big Yellow Bat Females are larger than males. Range: mm Average: 17 g Range: g 7

Cave Myotis (Myotis velifer) FIELD GUIDE TO NORTH AMERICAN MAMMALS FAMILY: Vespertilionidae The cave myotis, one of the larger myotis species, has a stubby nosed appearance.

They breed seasonally, giving birth to a single offspring of about 3 g, or 25 percent or more the weight of the mother.

13 Cave Myotis (Myotis velifer) FIELD GUIDE TO NORTH AMERICAN MAMMALS FAMILY: Vespertilionidae The cave myotis, one of the larger myotis species, has a stubby nosed appearance. The ears reach only to the end of the short nose when bent forward. Typical of North American bats, cave myotis feed on insects, especially moths and beetles. They breed seasonally, giving birth to a single offspring of about 3 g, or 25 percent or more the weight of the mother. The young are flying and foraging for insects when they are about a month old, but nurse for about six weeks. A nursing bat hangs upside down next to its mother, nestled in her wing, sometimes hanging onto the roost with one foot and its mother with the other; the female has a nipple under each arm, near her armpits. Females have longer forearms than males. Myotis velifer inset shows darker variation Average: 56.7 mm Range: mm Average: 12 g Range: 9 14 g 8

Evening Bat (Nycticeius humeralis) FAMILY: Vespertilionidae FIELD GUIDE TO NORTH AMERICAN MAMMALS Evening bats that roost together seem to share information about the location of rich foraging

Evening bats have never been found roosting in caves.

14 Evening Bat (Nycticeius humeralis) FAMILY: Vespertilionidae FIELD GUIDE TO NORTH AMERICAN MAMMALS Evening bats that roost together seem to share information about the location of rich foraging patches and alternative roosting sites. When they forage on farms, they are a boon to farmers, because the bats eat cucumber beetles (the adult stage in the life of the southern corn rootworm). Evening bats have never been found roosting in caves. Summer maternity colonies have been found in buildings and hollow trees; in the winter, bats of this species have been found roosting in palm fronds in Florida. Females and young appear to migrate fairly long distances; one individual was located 520 km from where it had been caught and tagged. Only females migrate northward in the summer; males apparently remain in warm southern locations year round. Females are larger than males. Range: mm Range: 9 14 g 9

Eastern Pipistrelle (Pipistrellus subflavus) FAMILY: Vespertilionidae FIELD GUIDE TO NORTH AMERICAN MAMMALS Not as small as its western cousin, the eastern pipistrelle weighs in at 6 to10 g and is

Eastern pipistrelles are stronger fliers than western pipistrelles, and some migrate several hundred miles in late summer and early fall, to the caves where they hibernate.

15 Eastern Pipistrelle (Pipistrellus subflavus) FAMILY: Vespertilionidae FIELD GUIDE TO NORTH AMERICAN MAMMALS Not as small as its western cousin, the eastern pipistrelle weighs in at 6 to10 g and is comparable in size to many bats in the family Vespertilionidae. Eastern pipistrelles are stronger fliers than western pipistrelles, and some migrate several hundred miles in late summer and early fall, to the caves where they hibernate. Like their cousins, female eastern pipistrelles give birth to twins. The neonates are hairless, but develop rapidly and are able to fly when they are two to three weeks old. Males have been known to live to 15 years of age; the maximum recorded longevity for females is 10 years. Pipistrelle Pipistrellus subflavus inset shows tri colored hair Females are larger than males. Range: mm Range: 6 01 g 10

FIELD GUIDE TO NORTH AMERICAN MAMMALS Brazilian Free tailed Bat (Tadarida brasiliensis) FAMILY: Molossidae Conservation Status: Near Threatened.

Gigantic colonies summer in Bracken Cave, Texas; Carlsbad Caverns, New Mexico; and even within the city of Austin, Texas, under the Congress Avenue Bridge.

16 FIELD GUIDE TO NORTH AMERICAN MAMMALS Brazilian Free tailed Bat (Tadarida brasiliensis) FAMILY: Molossidae Conservation Status: Near Threatened. Millions of Brazilian free tailed bats spend their summers in the southwestern United States. Gigantic colonies summer in Bracken Cave, Texas; Carlsbad Caverns, New Mexico; and even within the city of Austin, Texas, under the Congress Avenue Bridge. They are a spectacular sight spiraling out of their day roosts like great, dark, swirling clouds when they emerge in the evening to forage. The bats eat untold numbers of insects each night, sometimes catching their prey at altitudes of a mile or more. They typically migrate to central and southern Mexico in the winter, where they live in smaller colonies. They mate there, and fly north again as far as 1,300 km between February and April. Females give birth to a single pup, in June, and nurse it for about six weeks. Although they number in the millions, conservation is a concern, because they raise their young in a limited number of caves, and because pesticides can accumulate in their body tissues. Guano Bat, Mexican Free tailed Bat Males may be about 5% longer than females but females weigh about 5% more than males. Average: 95 mm Range: mm Range: g 1

Eastern Cottontail (Sylvilagus floridanus) ORDER: Lagomorpha FAMILY: Leporidae FIELD GUIDE TO NORTH AMERICAN MAMMALS for Latitude: 28º 15' North Longitude: 98º 30' West Texas, United States Eastern

They have been transplanted to areas outside their historically widespread range, which included swamps, prairies, woodlands, and forests.

17 Eastern Cottontail (Sylvilagus floridanus) ORDER: Lagomorpha FAMILY: Leporidae FIELD GUIDE TO NORTH AMERICAN MAMMALS for Latitude: 28º 15' North Longitude: 98º 30' West Texas, United States Eastern Cottontails share habitats with seven other cottontails and six species of hares. They have been transplanted to areas outside their historically widespread range, which included swamps, prairies, woodlands, and forests. They have two ways of escaping danger: a zig zag dash or a slink, in which they creep along, low to the ground, with their ears back. Eastern Cottontails are among the most prolific lagomorphs. Females can have seven litters a year, producing as many as 35 young. Litters, usually of 3, are born in a fur lined nest of dried grasses and leaves. Credit: painting by Ron Klinger from Kays and Wilson's Florida Cottontail Females are larger than males. Average: 430 mm Range: mm Range: 801 1,533 g 2

FIELD GUIDE TO NORTH AMERICAN MAMMALS for Latitude: 28º 15' North Longitude: 98º 30' West Texas, United States Black tailed Jackrabbit (Lepus californicus) ORDER: Lagomorpha FAMILY: Leporidae Black

They live in some of the hottest and driest regions of the continent, can survive on poor quality foods, and get most or all of the water they need from their food.

18 FIELD GUIDE TO NORTH AMERICAN MAMMALS for Latitude: 28º 15' North Longitude: 98º 30' West Texas, United States Black tailed Jackrabbit (Lepus californicus) ORDER: Lagomorpha FAMILY: Leporidae Black tailed Jackrabbits are tremendous leapers, able to jump more than 6 m horizontally. They live in some of the hottest and driest regions of the continent, can survive on poor quality foods, and get most or all of the water they need from their food. Where they can, they eat green vegetation, but they can survive in parts of the Southwest where creosote bush forms a large part of their diet. They cope with extreme heat by lowering their metabolism and resting in the shade during the day, which conserves water. They get rid of extra salt through their urine, and blood flows close to the skin in their enormous ears, a cooling mechanism. Although mostly nocturnal and solitary, large groups sometimes form near a good food supply. With their typically high reproductive output, Black tails can be agricultural pests, and there were periods in the 1800s and 1900s when aggressive rabbit drives herded and destroyed 5,000 6,000 animal in a single day. In spite of this, they are quite common and widespread. Credit: painting by Ron Klinger from Kays and Wilson's Member of order Lagomorpha. California Jackrabbit Range: mm Range: 1,300 3,300 g 1

Pygmy Rabbit (Brachylagus idahoensis)

Pygmy Rabbit (Brachylagus idahoensis) Conservation Status: Near Threatened. FIELD GUIDE TO NORTH AMERICAN MAMMALS Pygmy Rabbits dig extensive burrow systems, which are also used by other animals. Loss