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VIII. ILLUSTRATED CHECKLISTS OF ANIMALS
A. MAMMALS

Data provided are specific to the geographical scope of this paper. Descriptions of mammals are limited to adults. Characters given are primarily those which are outstanding and distinguish 1) orders, families, or major groups within a family, 2) one species from other similar species, and 3) males from females of a species. Primarily two measurements are provided: HB) the length of the head and body from the tip of the nose to the base of the tail and T) the length of the tail. The height at the shoulder is noted where customary. Approximate weights are given for the larger animals. Some details of the natural history are provided as identification aids.

The arrangement of this information is as follows: order (common names within order), characters common to the order (or major group within the order), common names of individual species (scientific name, family name), size, description, and habitat. Descriptions mostly follow The Audubon Society Field Guide to North American Mammals.

Next to each written description is a graphic illustration taken with permission from California Department of Fish and Game's California's Wildlife.

MARSUPIALIA (Marsupials or pouched mammals)
Marsupial females have no placenta, rather a pouch in which newborn embryos and older juveniles are nourished and carried.

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Opossum, Virginia opossum (Didelphis virginiana, Didelphidae) HB 15 to 20 inches; T 10 to 21 inches. The opossum is approximately the size of a house cat. The fur on its back is grizzled white and may appear brown or blackish. Its belly has black-tipped fur covered with white hairs. Its long, naked, prehensile tail is conspicuous. The opossum is active yearlong. It is nocturnal (active from dusk through dawn). It inhabits moist woodland and brushy habitats in riparian, woodland, scrubland, and urban communities. It is less common in grassland communities.

 
INSECTIVORA (Insectivores)
Shrews and moles have short, dense fur, small eyes, and five clawed toes on their fore and hind feet. Their small ears are usually hidden under their fur. They eat a variety of invertebrates.

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Ornate shrew, adorned shrew (Sorex ornatus, Soricidae) HB 2 and 21/2 inches; T 11/4 to 13/4 inches. The ornate shrew's back is grayish-brown; its belly lighter. The tail is dark brown above, lighter below, and is darkest at the tip. The ornate shrew is active year-round. It is crepuscular and nocturnal. It inhabits woodland, chaparral, grassland, and emergent riparian communities. However it is not often seen.

 

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Broad-footed mole (Scapanus latimanus, Talpidae) HB 41/2 to 53/4 inches long; T 3/4 to 13/4 inches. The broad-footed mole is brown-gray in color. It has a short, hairy tail. It is active yearlong both day and night, especially after rains. It burrows just below the surface, pushing the surface slightly upward. It inhabits annual grassland, pastoral, and riparian communities.

 
CHIROPTERA (Bats)
BATS have enlarged arm bones and muscles that resemble wings. They are able to walk and climb as well as fly. They may swing from branch to branch. At rest, they hang upside down by their feet (sometimes just one foot). Their eyes are small, and they have poor vision. However, they have highly developed echolocation, projecting through their noses and/or mouths 30 to 60 squeaks per second at a frequency of 30,000 to 100,000 cycles per second. This is inaudible to humans. (The human voice has a much lower frequency, between 300 and 3,000 cycles per second.) Bats also utter shrill chirps and screeches. Most mate in fall and undergo delayed fertilization (births occur after the cold winter). They live up to 20 years. They are insectivorous.
EVENING BATS have ear lobes that form a tragus: a projection from the ear's inner base. Their tails extend only a bit beyond the edge of the interfemoral membrane.

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Hoary bat (Lasiurus cinereus, Vespertilionidae) HB 2 to 31/2 inches; T 13/4 to 21/2 inches. The hoary bat's back has fur that is light brown and is tipped in white. Its throat is a buff color. It hibernates. When active, it is nocturnal. By day it hangs from the branches of evergreen trees. It eats mostly moths. It inhabits woodland communities, particularly open habitats and community edges.

 

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Pallid bat (Antrozous pallidus, Vespertilionidae) HB 3 inches; T 11/2.to 17//8 inches. The pallid bat has big ears. It is cream-colored or beige above and almost white below. It hibernates. It is nocturnal. It eats a variety of insects, as well as scorpions and lizards. It has a variety of habitats, especially open, dry areas with rocky places for roosting within grassland, woodland, and scrubland communities.

 
FREE-TAILED BATS are snub-nosed and thick set. They have naked tails which extend well beyond the edge of the interfemoral membrane. At least half of the tail is free. The thumb and toe claws have double talons. The spoon-shaped bristles on the hind toe of their feet are used in grooming.

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Brazilian free-tailed bat (Tadarida brasiliensis, Molossidae) HB 2 to 23/4 inches; T 11/2 to 13/4 inches. This bat's fur is dark brown-gray above, although the hairs are whitish at their base. It can be active yearlong, but locally it hibernates. It is nocturnal. It often forms huge colonies in caves in the southwest. It occupies all habitats, especially open areas in woodland, scrubland, and grassland communities. It is very common.

 
LAGOMORPHA (Rabbits and hares)
RABBITS AND HARES have two pairs of upper incisors, the larger pair in front of the more reduced pair. As in rodents, these continue to grow throughout the life of the animal, but are worn down by use. Rabbits and hares have relatively long ears and hind legs adapted for jumping. Their prominent eyes bulge to the sides of their heads, providing them with a wide field of vision and better protection from predators. Their sense of smell is well developed. They also sense vibrations in the ground and thump with their hind legs to communicate with one another. Another form of communication used is a piercing call of distress. They are grazers.

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Brush rabbit (Sylvilagus bachmani, Leporidae) HB 10 to 13 inches; T 3/4 to 13/4 inches. The brush rabbit's fur is a reddish brown mottled with black, lighter in winter. It has short legs, a small tail, and short, dark ears. It is active year-round. It is mainly crepuscular, but may also be active day or night. It inhabits dense, brushy areas of grassland, scrubland, and coastal live oak woodland communities.

 

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Audubon's (Desert) cottontail (Sylvilagus audubonii, Leporidae) HB 12 to 131/2 inches; T 13/4 to 3 inches. This rabbit is buff-brown above and white below. It has moderately long ears. It is active yearlong. It is primarily crepuscular, but occasionally is active by day or night. It uses small, scattered patches of dense scrub for cover and patches of scrub edged with a herbaceous cover for foraging. It occupies riparian woodland communities.

 

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Black-tailed hare (jackrabbit) (Lepus californicus, Leporidae) HB 16 to 20 inches; T 2 to 41/2 inches. The black-tailed hare is buff-sandy-gray peppered with black above and white below. It has very long ears. The upper side of its tail has a black stripe bordered in white which extends onto the rump. It is active yearlong. It is diurnal, and especially active in the late afternoon. It inhabits herbaceous and dry, shrubby areas in woodland, chaparral, and coastal scrub, particularly where these communities are edged by grassland.

 
RODENTIA (Squirrels, rats, mice, and relatives)
RODENTS are the most numerous and diverse group of mammals. They have only two pairs of incisors, upper and lower. They have no canines before the molars, only a gap. As in rabbits and hares, the incisors grow throughout the life of the rodent and are kept from growing too large by gnawing. Rodents' eyes bulge from the sides of their heads which permits them to see in front of and behind them. Most rodents have four toes on their fore feet and five on the hind feet.
SQUIRRELS are primarily diurnal. Many hibernate, and some estivate.

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California ground squirrel (Spermophilus beecheyi, Sciuridae) HB 8 to 11 inches; T 6 to 9 inches. This squirrel is brownish with buff-colored flecks. It has whitish areas along the sides of the neck across the shoulders to the haunches and a dark V-shaped pattern across the back of the shoulders (with the 'V' pointing forward). The bushy tail is brown-gray edged in white. The California ground squirrel is active yearlong, although it may become torpid when food is scarce and/or temperatures are extreme, especially in late summer. It is diurnal. It burrows in the ground and creates a central entrance mound from which radiate numerous pathways. It occupies open and disturbed areas, being particularly numerous in heavily grazed pastures.

 

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Western gray squirrel (Sciurus griseus, Sciuridae) HB 8 to 11 inches; T 91/2 to 12 inches. This squirrel is gray with many white-tipped hairs above. Its belly is white. The backs of its ears are reddish brown. Its long, bushy tail is banded in gray, white, and black. It is active year-round. It is diurnal, active especially in early morning and late afternoon/evening. It nests in trees, making large, round, hollow nests made of leaves. It inhabits riparian and mature coastal live oak woodland communities.

 
POCKET GOPHERS are found only in North America. They have stout bodies, short necks, short fur, small ears and eyes, a naked (or nearly naked) tail, and large, external fur-lined cheek pouches. Their lips close behind their incisors, so no dirt gets in their mouths while digging. They spend almost all the time underground in their burrows. Burrows are of two types: surface burrows for food gathering and deeper burrows for food storage and shelter. Pocket gophers do not hibernate, but stay in their burrows in winter.

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Botta's pocket gopher (Thomomys bottae, Geomyidae) HB 5 to 7 inches; T 13/4 to 33/4 inches. This animal is dark brown-gray above with a purplish cast on its sides; lighter below. Its tail is tan-gray and mostly hairless. It is active yearlong. It is primarily nocturnal, rarely spending much time above ground; it may be active day and/or night below ground. It creates very extensive burrows close to the surface, with its nest deeper into the ground. The burrow tailings form conspicuous mounds above ground. Botta's pocket gopher occupies perennial meadows, grasslands, and woodlands with moist, friable soils.

 
POCKET MICE are not really mice, but are more closely related to ground squirrels and pocket gophers. They occur only west of the Mississippi River. They are nocturnal burrowers. They have external fur-lined cheek pouches. They have moderately long tails and short hind legs. Most do not hibernate.

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California pocket mouse (Chaetodipus (Perognathus) californicus, Heteromyidae) HB 3 to 4 inches; T 4 to 6 inches. The California pocket mouse is brown-gray with white bristles/spines on the rump and a brownish line along its side. The very long tail is somewhat tufted and is brown above and white below. Above ground, its activity decreases during winter cold spells. It inhabits chaparral and grassland communities, especially where the two occur side by side. It also occupies habitats within coastal scrub, chaparral, and woodland communities.

 
NEW WORLD MICE AND RELATIVES comprise the largest family of mammals in North America. As would be expected, there is considerable variety in habits and form. Most species use burrows. None hibernates. Based on dental structure, there are two groups: cricetines (mice, deer mice, and woodrats) and microtines (voles).
Most CRICETINE MICE have long tails and large eyes and ears. Their teeth have well-developed cusps. They are omnivorous and nocturnal.

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Western harvest mouse (Reithrodontomys megalotis, Cricetidae) HB 21/2 to 3 inches; T 2 to 4 inches. This tiny mouse is brownish above, white below, and buff-colored along the sides. Its incisors are deeply grooved. It is active year-round. Western harvest mice are active in late afternoon and at night, especially on moonless and rainy nights. They use the burrows of other rodents. They are found especially in grassland, scrubland, and woodland communities with water.

 

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California mouse (Peromyscus californicus, Cricetidae) HB 41/2 to 5 inches; T 41/2 to 6 inches. The California mouse is yellowish brown or gray mixed with black above, whitish below, and often has a buff-colored spot on its breast. It has two rows of cusps on its teeth. It has internal cheek pouches. It is active yearlong, though it may undergo periods of torpor in times of food shortage. It is nocturnal, its activity level peaking just before dawn. It often lives in the stick houses built by the dusky-footed woodrat (Neotoma fuscipes). It occurs in mixed or mature chaparral, coastal scrub, coastal scrub interspersed with grassland, and coastal live oak woodland, especially dense "oak-bay woodland"

 

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Deer mouse (Peromyscus maniculatus, Cricetidae) HB 3 to 4 inches; T 13/4 to 43/4 inches. The deer mouse is gray-reddish brown above and white below. Its tail is bicolored and short-haired. It has two rows of cusps on its teeth. It has internal cheek pouches. It is active yearlong and is nocturnal. It is ubiquitous, occupying all habitat types, especially in woodland and scrubland communities.

 

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Brush mouse (Peromyscus boylii, Cricetidae) HB 31/2 to 43/4 inches; T 31/2 to 43/4 inches. The brush mouse is brown-gray above; white below. It has buff-colored-tawny sides. Its tail is bicolored and hairy. It has two rows of cusps on its teeth. It has internal cheek pouches. It is active year-round and is nocturnal. Its nest is made of dried vegetation under brush piles or in rocky crevices. It inhabits chaparral, especially mesic environments with dense shrub and ground cover.

 
WOODRATS have large ears and look like overgrown deer mice. They love anything shiny. They eat green vegetation, as well as seeds, fruit, and nuts.

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Dusky-footed woodrat (Neotoma fuscipes, Cricetidae) HB 6 to 7 inches; T 61/4 to 123/4 inches. This woodrat is buff-brown above and gray-white below. Its face is grayish. Its belly is often washed with a tan color. Its feet are two-toned: a dusky color with white toes. Its tail is brown above and lighter below. It is active yearlong. Mostly, it is nocturnal. It builds elaborate stick houses on the ground or in trees. It inhabits areas of dense, brushy understory, especially if evergreen, in chaparral and coastal live oak woodland communities.

 

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Desert woodrat (Neotoma lepida, Cricetidae) HB 5 to 8 inches; T 33/4 to 71/2 inches. The desert woodrat is buff-gray above and grayish below. The tail is also bicolored. Its hind feet are all white, whereas the dusky-footed woodrat's are two-toned. All its fur is gray at the base. It may take over the old burrow of a ground squirrel, building up a stick house around the entrance. It inhabits rocky slopes in Yucca scrub communities.

 
VOLES are microtines with stout bodies, short legs and tails, and tiny ears and eyes. Their teeth are molarized (the crowns are flattened) which enables them to grind the grasses and leaves that they eat. They are active day and night and year-round.

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California vole (Microtus californicus, Cricetidae) HB 43/4 to 51/2 inches; T 11/2 to 23/4 inches. The California vole is grizzled brown with scattered black hairs above and gray below. Its fur is often white-tipped. Its feet are pale, and its long tail is bicolored. It occupies varied habitats with friable soils, especially in riparian and dense annual grassland communities.

 
OLD WORLD RATS AND MICE have long tails and large ears. They differ from native rats and mice by their molariform teeth which have three rows of cusps instead of two. They are primarily nocturnal and active year-round.

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Black rat, ship rat (Rattus rattus, Muridae) HB 61/2 to 8 inches; T 61/4 to 10 inches. The black rat is brown or gray above and gray-whitish below. Its tail is dark and scaly and has few hairs. Although it is primarily nocturnal, it is occasionally active by day. It is found primarily in riparian communities, especially near human homes and/or open dumps. It may also occur in dense vegetation away from human habitation.

 

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House mouse (Mus musculus, Muridae) HB 21/2 to 33/4 inches; T 21/2 to 4 inches. The house mouse is gray-brown above and nearly as dark below. Its dusky-colored tail has few hairs. It inhabits buildings and fields, as well as ruderal herbaceous, shrubby, and riparian habitats near human homes. The white lab mouse has been bred from this species.

 
CARNIVORA (Carnivores)
All have three pairs of upper and lower incisors, as well as strong canines. Most are carnivorous; many are omnivorous. None hibernates, although some may spend considerable time in their nests during the cold weather.
COYOTE AND FOXES have a long, narrow muzzle, erect, triangular ears, strong, thin legs, and a bushy tail. They have excellent vision, hearing, and sense of smell. Most chase down their prey, but foxes also stalk and pounce.

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Coyote (Canis latrans, Canidae) HB 291/2 to 361/2 inches; T 113/4 to 151/2 inches. The coyote is 23-26 inches high at the shoulder and weighs between 20 and 40 pounds. It is grizzled gray or reddish gray with some buff color. Its legs are rusty-yellowish in color; its lower foreleg bears a dark vertical line. It has a bushy tail with a black tip. Coyotes hunt in small groups or in pairs. The coyote is active yearlong. It is crepuscular and nocturnal, occasionally diurnal. It occurs in open brush, scrub, and herbaceous habitats, as well as open woodlands with low to intermediate canopy and some shrub-grass understory. It inhabits areas near free water.

 

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Gray fox (Urocyon cinereoargenteus, Canidae) HB 223/4 to 27 inches; T 83/4 to 171/2 inches. The gray fox is 14 to 15 inches high at the shoulder and weighs between 7 and 13 pounds. It is grizzled gray above and reddish below and on the back of the head. It has a white throat. Its tail is black above and at the tip. It has rusty-colored feet. It is a solitary animal. It is active yearlong, especially during crepuscular and nocturnal hours. It is occasionally diurnal. It occupies meadows and scrubland, riparian, and woodland communities.

 
RACCOONS are distinguished by their masked faces and long, banded tails. Their blunt teeth suggest that raccoons are not strictly carnivores, but are well adapted as omnivores. They have five clawed toes on each foot and walk flat on the soles of their feet (like bear and human). They may den in hollow trees or caves, or use burrows in the ground. They are social and stay in family groups. They are nocturnal.

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Raccoon (Procyon lotor, Procyonidae) HB 161/4 to 211/2 inches; T 71/2 to 16 inches. The raccoon weighs between 12 and 48 pounds. It is reddish brown above with lots of black in its fur. Below it is gray. Its bushy tail is banded (four to six bands) in black and brown or black and gray. The fur on its face is colored such that the raccoon appears to be wearing a black mask outlined in white. It stays in its nest when the weather is very cold. The raccoon occurs in most habitats whether natural or anthropogenic, especially in riparian, scrubland, and woodland communities. Water must be available nearby.

 
WEASELS, BADGERS, AND SKUNKS have paired anal scent glands used, in weasels and badgers, for social and sexual communication and, in skunks, for personal defense. They have long bodies on short legs. They have short, rounded ears. Their fur is very soft. They are solitary. They are primarily nocturnal and are active yearlong.

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Long-tailed weasel (Mustela frenata, Mustelidae) HB 8 to 151/4 inches; T 3 to 61/2 inches. The long-tailed weasel weighs between 1/4 and just over 1/2 pound. Its black nose and eyes are bright against the brown face with some white fur. It is reddish brown above and whitish below. Its tail is brown with a black tip. The legs seem very short in proportion to the rest of the body. Its feet are brownish. It can be active both day and night. It inhabits most areas except the most extremely xeric ones. It uses a mixture of habitats, especially in riparian woodland and scrubland communities. Weasels are instrumental in helping to control the rodent population, but also eat other small mammals.

 

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Badger (Taxidea taxus, Mustelidae) HB 161/2 to 28 inches; T 4 to 6 inches. The badger weighs between 8 and 25 pounds. Its flattish body has short, bowed legs. It has shaggy fur that is grizzled gray-brown. It has a white stripe from its shoulder to its snout. Its cheeks are white with a black patch. Its yellowish tail is short and bushy. Its feet are dark, and it has large fore claws. The badger can be active both night and day. It may experience variable periods of torpor in winter. It frequently digs in California ground squirrel colonies; it is a powerful burrower. It inhabits the open areas with dry, friable soils in most scrubland, woodland, and herbaceous communities. It hunts small mammals, especially rodents, as well as birds, invertebrates, and rattlesnakes. It also eats carrion.

 

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Striped skunk (Mephitis mephitis, Mustelidae) HB 13 to 16 inches; T 7 to 151/2 inches. This skunk weighs between 6 and 14 pounds. It is mainly black. It has two broad white stripes that run up its back and meet in a cap on its head. There is a thin white stripe down the center of its face. Its bushy black tail is often fringed and/or tipped in white. Although it is mainly nocturnal, it may occasionally be crepuscular. It is found in nearly all habitats, especially in riparian woodland and herbaceous and grassy habitats in most communities and their ecotones. It is common in anthropogenic communities. Skunks are omnivorous.

 
CATS are sleek animals with strong legs. They have short, somewhat rounded ears, long, sensitive whiskers, and eyes facing forward. They have excellent night vision. Their teeth are well adapted for their carnivorous lifestyle: the molariform teeth have shearing edges, and the canine teeth are large fangs. Their fore feet have five toes, their hind feet have four, all with retractile claws. Their foot pads are soft, enabling them to silently stalk their prey. Most are nocturnal and solitary, except during mating season. They are active year-round.

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Mountain lion, cougar, puma (Felis concolor, Felidae) HB 38 to 72 inches; T 21 to 36 inches. The mountain lion weighs between 75 and 275 pounds. It is yellowish-tawny above and white under buff below. Adults are not spotted, but juveniles are buff with black spotting. The long tail is black-tipped. Mountain lions are mostly nocturnal and crepuscular. They inhabit most areas, especially riparian and brushy areas of most communities in Poly Canyon.

 

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Bobcat (Felis rufus, Felidae) HB 24 to 44 inches; T 4 to 7 inches. The bobcat weighs between 14 and 68 pounds. It is tawny-colored (grayer in winter), with indistinct blackish spotting. It has a short, stubby tail with two to three bars and a black tip above, white below. Its upper legs have dark horizontal bars. Its face has thin black lines that radiate onto its broad cheek ruff. Its ears are somewhat tufted, though this is difficult to see at a distance. It is mostly nocturnal and crepuscular, although it may also be active by day. It inhabits most areas, especially brushy riparian and coastal live oak woodland communities, as well as chaparral. It also forages in grasslands.

 
ARTIODACTYLA (Even-toed ungulates)
In Poly Canyon, the only EVEN-TOED HOOFED MAMMAL is the mule deer. It is herbivorous, and its molariform teeth are well adapted for grinding vegetation. Also, even-toed hoofed mammals have a cartilaginous pad instead of incisors at the front of their upper jaw. Males have antlers that are made of bone and are shed each year. Antlers become larger and have more points each year until the individual reaches maturity. Females are generally smaller than males. Fawns have spotted coats.

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Mule deer, black-tailed deer (Odocoileus hemionus, Cervidae) HB 31/2 to 53/4 feet; T 41/2 to 9 inches. The mule deer is 3 to 31/2 feet high at the shoulder. Males weigh between 110 and 475 pounds; females weigh between 70 and 160 pounds. In summer mule deer are reddish or yellowish brown above; in winter they become grayer above. They are creamy-tan below. The tail is white above and tipped with black (mule deer) or is blackish/brownish above and to the tip (black-tailed deer). It is active yearlong. It is usually crepuscular, but may be active day or night. It is found in woodland and scrubland habitats, especially in a mosaic of various-aged vegetation that provides wooded areas for cover, meadows and shrubby clearings for feeding, and free water.