Mammals of Pennsylvania

52 established wild species in Pennsylvania. Plus 17 range-listed species with few or no digitized records.

All species A-Z →

Alleghanian spotted skunk foraging among rocks and pine needles in daylight

Alleghanian Spotted Skunk

Spilogale putorius

Range-listed · no digitized records yet
Size 32 cm12.6 in Weight 583 g1.3 lb active by night forest edge
Neotoma magister

Allegheny Woodrat

Neotoma magister

Occasional in Pennsylvania 25 sightings
Size 31–45 cm12.2–17.7 in Weight 357 g12.6 oz active by night rocky outcrop

Sightings by month

Beaver swimming low in murky green pond water with only its wet head and back above the surface

American Beaver

Castor canadensis

Common in Pennsylvania 1,758 sightings
Size 60–90 cm2–3 ft Weight 11–32 kg24.3–70.5 lb active day & night river

Sightings by month

Oso negro (Ursus americanus), Parque natural provincial Tatshenshini-Alsek, Yukón, Canadá, 2017-08-25, DD 85

American Black Bear

Ursus americanus

Common in Pennsylvania 1,276 sightings
Size 1.2–2 m3.9–6.6 ft Weight 40–250 kg88.2–551.2 lb active by night conifer forest

Sightings by month

Mustela Erminea head

American Ermine

Mustela erminea

Occasional in Pennsylvania 26 sightings
Size 17–33 cm6.7–13 in Weight 70–260 g2.5–9.2 oz active by night coniferous forest

Sightings by month

Norka amerykańska (neovison vison)

American Mink

Neogale vison

Common in Pennsylvania 597 sightings
Size 33–45.7 cm13–18 in Weight 0.5–1.4 kg1–3 lb active day & night lake

Sightings by month

American pygmy shrew crossing an asphalt path

American pygmy shrew

Sorex hoyi

Marginal occurrence · 1 record
Size 5–7 cm2–2.8 in Weight 2–5 g0.1–0.2 oz active day & night deciduous forest
Tamiasciurus hudsonicus James Gardens

American Red Squirrel

Tamiasciurus hudsonicus

Common in Pennsylvania 1,532 sightings
Size 17–23 cm6.7–9.1 in Weight 140–310 g4.9–10.9 oz active by day wetland

Sightings by month

American water shrew swimming at the surface of a stream, seen from above

American water shrew

Sorex palustris

Marginal occurrence · 1 record
Size 8 cm3.1 in Weight 8–18 g0.3–0.6 oz active day & night river
Appalachian Cottontail (Sylvilagus obscurus)

Appalachian Cottontail

Sylvilagus obscurus

Marginal occurrence · 4 records
Size 38.1–43.2 cm15–17 in Weight 0.8–1.2 kg1.7–2.5 lb active by day river

Sightings by month

Big Brown Bats (Eptesicus fuscus)

Big Brown Bat

Eptesicus fuscus

Common in Pennsylvania 455 sightings
Size 7.5 cm3 in Weight 17 g0.6 oz active by night agricultural

Sightings by month

Live black rat climbing through branches

Black Rat

Rattus rattus

Range-listed · no digitized records yet
Size 16–24 cm6.3–9.4 in Weight 75–230 g2.6–8.1 oz active by night agricultural
Bobcat (Lynx rufus)

Bobcat

Lynx rufus

Occasional in Pennsylvania 193 sightings
Size 30–60 cm11.8–23.6 in Weight 4–18 kg8.8–39.7 lb active by night forest edge

Sightings by month

Common Raccoon in Hugh Taylor Birch State Park

Common Raccoon

Procyon lotor

Common in Pennsylvania 3,625 sightings
Size 40–70 cm1.3–2.3 ft Weight 3.5–9 kg7.7–19.8 lb active by night mixed forest

Sightings by month

Mother Coyote Sitting, Watching Over Den, Photo 1 of 2 (47924154788)

Coyote

Canis latrans

Common in Pennsylvania 599 sightings
Size 0.8–1 m2.5–3.3 ft Weight 7–21 kg15.4–46.3 lb active day & night urban

Sightings by month

Eastern Chipmunk (Tamias striatus)

Eastern Chipmunk

Tamias striatus

Common in Pennsylvania 5,784 sightings
Size 16.6 cm6.5 in Weight 93 g3.3 oz active by day urban

Sightings by month

Blacklick Woods - Eastern cottontail feeding 1

Eastern Cottontail

Sylvilagus floridanus

Common in Pennsylvania 7,993 sightings
Size 36–43 cm14.2–16.9 in Weight 0.8–1.5 kg1.8–3.3 lb active day & night lake

Sightings by month

Grey squirrel (Sciurus carolinensis) 01

Eastern Gray Squirrel

Sciurus carolinensis

Common in Pennsylvania 13,560 sightings
Size 23–30 cm9.1–11.8 in Weight 400–710 g0.9–1.6 lb active by day wetland

Sightings by month

Eastern Mole (Scalopus aquaticus)

Eastern Mole

Scalopus aquaticus

Occasional in Pennsylvania 27 sightings
Size 14.8 cm5.8 in Weight 75 g2.6 oz active day & night river

Sightings by month

Eastern red bat roosting among green leaves, disguised as a dead leaf

Eastern Red Bat

Lasiurus borealis

Occasional in Pennsylvania 176 sightings
Size 9.3–11.7 cm3.7–4.6 in Weight 7–13 g0.2–0.5 oz active by night desert

Sightings by month

Eastern small-footed myotis clinging to a weathered wooden post in daylight, unhandled and alert

Eastern Small-footed Myotis

Myotis leibii

Rarely seen in Pennsylvania 6 sightings
Size 7.5–8.5 cm3–3.3 in Weight 5 g0.2 oz active by night cave

Sightings by month

AI-generated image: Eastern Water Shrew drinking at stream edge beside mossy log. No public-domain photograph of this species exists. This image was generated with AI from verified reference material and reviewed by our editorial team for accuracy

Eastern Water Shrew

Sorex albibarbis

Rarely seen in Pennsylvania 1 sighting
Size 13–17 cm5.1–6.7 in Weight 8–18 g0.3–0.6 oz active day & night riparian

Sightings by month

Elk (Cervus canadensis)

Elk

Cervus canadensis

Common in Pennsylvania 554 sightings
Size 1.6–2.7 m5.2–8.9 ft Weight 178–497 kg392.4–1095.7 lb active day & night forest edge

Sightings by month

Fallow deer in field

European Fallow Deer

Dama dama

Marginal occurrence · 1 record
Size 1.3–1.8 m4.3–5.9 ft Weight 30–100 kg66.1–220.5 lb active day & night mixed forest

Sightings by month

European rabbit feeding in dry vegetation

European Rabbit

Oryctolagus cuniculus

Occasional in Pennsylvania 19 sightings
Size 34–50 cm13.4–19.7 in Weight 1–2.5 kg2.2–5.5 lb active by night grassland

Sightings by month

Evening bat resting, brown fur and dark ears and wings visible, not restrained

Evening Bat

Nycticeius humeralis

Range-listed · no digitized records yet
Size 5 cm2 in Weight 7–15 g0.2–0.5 oz active by night agricultural
Martes Pennanti

Fisher

Pekania pennanti

Occasional in Pennsylvania 196 sightings
Size 75–95 cm2.5–3.1 ft Weight 3.5–6 kg7.7–13.2 lb active dawn & dusk wetland

Sightings by month

Atelerix albiventris in Spain

Four-toed Hedgehog

Atelerix albiventris

Marginal occurrence · 1 record
Size 15–27 cm5.9–10.6 in Weight 250–600 g0.6–1.3 lb active by night savanna
Sciurus niger

Fox Squirrel

Sciurus niger

Common in Pennsylvania 1,070 sightings
Size 25.4–38.1 cm10–15 in Weight 804 g1.8 lb active by day river

Sightings by month

Gray fox standing in dappled woodland

Gray Fox

Urocyon cinereoargenteus

Common in Pennsylvania 263 sightings
Size 0.8–1.1 m2.5–3.7 ft Weight 3–9 kg6.6–19.8 lb active day & night brushy woodland

Sightings by month

Silver-gray wolf walking along a gravel bank in Alaska

Gray Wolf

Canis lupus

Size 1.1–1.6 m3.4–5.2 ft Weight 23–80 kg50.7–176.4 lb active day & night cave

Sightings by month

Groundhog (Marmota monax)

Groundhog

Marmota monax

Common in Pennsylvania 4,497 sightings
Size 50.6 cm19.9 in Weight 3.4 kg7.5 lb active by day woodland

Sightings by month

Common seal (Phoca vitulina) 2

Harbor Seal

Phoca vitulina

Marginal occurrence · 1 record
Size 1.4–1.9 m4.6–6.2 ft Weight 55–170 kg121.3–374.8 lb active by day coastal
House mouse in dry plant litter

House Mouse

Mus musculus

Occasional in Pennsylvania 189 sightings
Size 5–10 cm2–3.9 in Weight 12–30 g0.4–1.1 oz active by night agricultural

Sightings by month

Indiana bats roosting in a dense cluster on a cave ceiling with several individuals in flight below

Indiana bat

Myotis sodalis

Occasional in Pennsylvania 17 sightings
Size 5.5 cm2.2 in Weight 5–10 g0.2–0.4 oz active by night agricultural

Sightings by month

Least Weasel (Mustela nivalis)

Least Weasel

Mustela nivalis

Marginal occurrence · 6 records
Size 26 cm10.2 in Weight 50 g1.8 oz active by night grassland
AI-generated image: Long-tailed Shrew in side profile on moss-covered wet rocks. No public-domain photograph of this species exists. This image was generated with AI from verified reference material and reviewed by our editorial team for accuracy

Long-tailed Shrew

Sorex dispar

Rarely seen in Pennsylvania 12 sightings
Size 6.6 cm2.6 in Weight 3–8 g0.1–0.3 oz active day & night river

Sightings by month

Long-tailed weasel standing alert in grass with its black-tipped tail curled behind it, Sonoma County, California

Long-tailed Weasel

Neogale frenata

Occasional in Pennsylvania 40 sightings
Size 24.8 cm9.8 in Weight 170 g6 oz active day & night wetland

Sightings by month

Sorex cinereus, Harwich, Chatham, Ontario, Canada 1

Masked Shrew

Sorex cinereus

Size 6.9 cm2.7 in Weight 5 g0.2 oz active day & night grassland

Sightings by month

Meriones unguiculatus (wild)

Mongolian gerbil

Meriones unguiculatus

Marginal occurrence · 1 record
Size 10–13 cm3.9–5.1 in Weight 50–130 g1.8–4.6 oz grassland

Sightings by month

Muskrats resting on a floating log in open water

Muskrat

Ondatra zibethicus

Common in Pennsylvania 706 sightings
Size 25–36 cm9.8–14.2 in Weight 0.6–2 kg1.3–4.4 lb active day & night wetland

Sightings by month

Deer Mouse (Peromyscus maniculatus) (9310532204)

North American Deermouse

Peromyscus maniculatus

Occasional in Pennsylvania 70 sightings
Size 8–10 cm3.1–3.9 in Weight 21 g0.7 oz active by night river

Sightings by month

North American least shrew moving through short grass

North American Least Shrew

Cryptotis parvus

Marginal occurrence · 4 records
Size 5–8 cm2–3.1 in Weight 6 g0.2 oz active by night grassland
Erethizontidae Erethizon dorsatum 3.2

North American Porcupine

Erethizon dorsatus

Common in Pennsylvania 1,067 sightings
Size 60–90 cm2–3 ft Weight 3.5–12 kg7.7–26.5 lb active by night mixed forest

Sightings by month

River Otter (Lontra canadensis)

North American River Otter

Lontra canadensis

Occasional in Pennsylvania 128 sightings
Size 0.7–1.1 m2.2–3.5 ft Weight 5–15 kg11–33.1 lb active day & night river

Sightings by month

Northern Flying Squirrel (Glaucomys sabrinus)

Northern Flying Squirrel

Glaucomys sabrinus

Occasional in Pennsylvania 13 sightings
Size 25–37 cm9.8–14.6 in Weight 148 g5.2 oz active by night mixed conifer

Sightings by month

Hoary bat in flight against blue sky, wings spread to show its yellow throat patch and heavily frosted fur

Northern Hoary Bat

Lasiurus cinereus

Occasional in Pennsylvania 14 sightings
Size 13–15 cm5.1–5.9 in Weight 26 g0.9 oz active by night cave

Sightings by month

Northern myotis hanging head-down from a rock ceiling, long ears and tan fur visible

Northern Myotis

Myotis septentrionalis

Rarely seen in Pennsylvania 11 sightings
Size 8.6 cm3.4 in Weight 6 g0.2 oz active by night coniferous forest

Sightings by month

Northern Short-tailed Shrew (Blarina brevicauda)

Northern Short-tailed Shrew

Blarina brevicauda

Size 11.1 cm4.4 in Weight 21 g0.7 oz active day & night riparian

Sightings by month

Live Norway rat beside shallow water

Norway Rat

Rattus norvegicus

Common in Pennsylvania 283 sightings
Size 15–28 cm5.9–11 in Weight 140–500 g0.3–1.1 lb active by night urban

Sightings by month

Red Fox (Vulpes vulpes)

Red Fox

Vulpes vulpes

Common in Pennsylvania 3,461 sightings
Size 43 cm16.9 in Weight 5–10 kg11–22 lb active day & night desert

Sightings by month

Microtus chrotorrhinus

Rock Vole

Microtus chrotorrhinus

Marginal occurrence · 3 records
Size 11.5 cm4.5 in Weight 39 g1.4 oz active day & night coniferous forest
Silver-haired bat tucked into loose bark

Silver-haired Bat

Lasionycteris noctivagans

Occasional in Pennsylvania 52 sightings
Size 9.5–11.5 cm3.7–4.5 in Weight 11 g0.4 oz active by night river

Sightings by month

Smoky shrew moving through dense green grass

Smoky Shrew

Sorex fumeus

Rarely seen in Pennsylvania 9 sightings
Size 7.4 cm2.9 in Weight 8 g0.3 oz active day & night river

Sightings by month

Lepus americanus 5459 cropped

Snowshoe Hare

Lepus americanus

Rarely seen in Pennsylvania 12 sightings
Size 41–52 cm16.1–20.5 in Weight 1.4–1.6 kg3.2–3.4 lb active by night coniferous forest

Sightings by month

AI-generated image: Southern bog lemming alert among wet sedges and sphagnum at a bog edge. No public-domain photograph of this species exists. This image was generated with AI from verified reference material and reviewed by our editorial team for accuracy

Southern Bog Lemming

Synaptomys cooperi

Marginal occurrence · 4 records
Size 11.8 cm4.6 in Weight 35 g1.2 oz active day & night mixed conifer
Southern Flying Squirrel-27527-1

Southern Flying Squirrel

Glaucomys volans

Common in Pennsylvania 232 sightings
Size 17.1 cm6.7 in Weight 65 g2.3 oz active by night deciduous forest

Sightings by month

Southern red-backed vole feeding among sunflower seeds on snow

Southern Red-backed Vole

Clethrionomys gapperi

Size 12–16.5 cm4.7–6.5 in Weight 6–42 g0.2–1.5 oz active by night mixed forest

Sightings by month

Star-nosed mole's fleshy 22-ray nose organ fanned out, close-up macro

Star-nosed mole

Condylura cristata

Occasional in Pennsylvania 102 sightings
Size 12.1 cm4.8 in Weight 52 g1.8 oz active day & night urban

Sightings by month

Mephitis mephitis in Dierenpark Zie-ZOO

Striped Skunk

Mephitis mephitis

Common in Pennsylvania 730 sightings
Size 46.5–81.5 cm1.5–2.7 ft Weight 0.6–6.3 kg1.3–13.9 lb active by night grassland

Sightings by month

Thirteen-lined ground squirrel crouched beside short grass

Thirteen-lined ground squirrel

Ictidomys tridecemlineatus

Range-listed · no digitized records yet
Size 17–30 cm6.7–11.8 in Weight 173 g6.1 oz active by day grassland
Tricolored Bat hibernating on a limestone mine wall

Tricolored Bat

Perimyotis subflavus

Occasional in Pennsylvania 36 sightings
Size 7.7–8.9 cm3–3.5 in Weight 5–8 g0.2–0.3 oz active by night cave

Sightings by month

Virginia Opossum clinging to a tree branch in a snowy winter woodland

Virginia Opossum

Didelphis virginiana

Common in Pennsylvania 1,325 sightings
Size 40.8 cm16.1 in Weight 1.1–1.6 kg2.5–3.6 lb active by night river

Sightings by month

Little brown myotis roosting alertly on a wooden beam

Western Little Brown Myotis

Myotis lucifugus

Occasional in Pennsylvania 42 sightings
Size 8–9.5 cm3.1–3.7 in Weight 6–13 g0.2–0.5 oz active by night cave

Sightings by month

White-footed mouse on a fallen log in leaf litter

White-footed Mouse

Peromyscus leucopus

Size 10.1 cm4 in Weight 20–30 g0.7–1.1 oz active by night urban

Sightings by month

White-nosed coati (Nasua narica) Peten

White-nosed Coati

Nasua narica

Marginal occurrence · 1 record
Size 0.8–1.3 m2.6–4.3 ft Weight 3–6 kg6.6–13.2 lb active by day oak-sycamore canyon

Sightings by month

White-tailed Deer (Odocoileus virginianus)

White-tailed Deer

Odocoileus virginianus

Common in Pennsylvania 19,814 sightings
Size 0.9–2.2 m3.1–7.2 ft Weight 68–136 kg149.9–299.8 lb active day & night mixed forest

Sightings by month

Adult wild boar foraging in grass

Wild Boar

Sus scrofa

Marginal occurrence · 8 records
Size 85–90 cm2.8–3 ft Weight 40–50 kg88.2–110.2 lb active day & night lake

Sightings by month

Microtus pinetorum - crlevy - 550023152

Woodland Vole

Microtus pinetorum

Occasional in Pennsylvania 25 sightings
Size 10.3 cm4.1 in Weight 26 g0.9 oz active day & night woodland

Sightings by month