Which Mammals Live in Massachusetts?


I went though Massachusetts to get to a whale watching trip recently. I was really surprized at how many different environments I drove through. The habitats ranged from scrubland, grassland, and forests. With the various mammals in the state, these habitats are essential for the mammals that live there.

Massachusetts currently has 83 different species of mammals, including bears, rodents, whales, porpoises, dolphins, and others.

According to the Massachusetts government website, there are currently over 80 species of mammals living in Massachusetts. I have excluded any extirpated or accidental sightings from this list.

Bats7
Bear1
Beaver1
Cats3
Deer2
Dolphin8
Fox and coyote2
Opossum1
Porcupine1
Porpoise1
Rabbits and hare5
Raccoon1
Rodents 9
Seals6
Shrews and moles8
Skunk1
Squirrel family4
Voles3
Weasels family3
Whales16

Source: Massachusetts Government Website

https://www.mass.gov/service-details/mammals-in-massachusetts

American Beaver

The North American beaver is a nocturnal semiaquatic mammal and the largest rodent in North America. They live in colonies, and have orange teeth because which contain a lot of iron. This makes their teeth stronger than regular teeth. They are well know for building dams, canals, and lodges.

Beaver
Beaver

Their color is dark brown, and they measure from 74 to 90 cm, weighing from 11 to 32 kg. The beaver is a herbivore and eats bark, cambium, roots, buds, and water plants. The North American beaver lives in forests (near water bodies) in the northern parts of North America, with a lifespan between 10 to 15 years. In Massachusetts they can be found in northeastern, central and Western Massachusetts, and occasionally in the southeast of the state.

American Black Bear

The American black bear is a midsize mammal from North America. Their color is not always black but can be brown, tan, and even blonde. They measure from 130 to 190 cm and weigh from 200 to 300 kg.

The black bear is an omnivore and has a very large diet. This consists mostly of fish, mammals, insects, grasses, roots, and berries. This species of bear is broadly distributed in forest habitats, with an average lifespan of 20 years.

The black bear can be found in most forests in the state, although not common in the Southeast of Barnstable, Plymouth or Bristol.

Black bear

American Water Shrew

The American water shrew is a solitary and semiaquatic species of shrew. Their color changes throughout the year, from light brown in the summer to black in the winter. The water shrew measures from 13 to 17 cm and weighs from 8 to 18 g.

This species of water shrew is an omnivore eating aquatic insects, small fish, plants, and snails. They live in streams and ponds, with a lifespan of about 18 months.

In Massachusetts they are listed as a species of special concern, and can be found in west Massachusetts in Berkshire, Franklin, Hampden and Hampshire. They can also be found in the centre of the county in Worcester.

Atlantic White-sided Dolphin

The Atlantic white-sided dolphin grows from 6.2-9.2ft (1.9-2.8m) with a weight between 360-520 lb. They are similar in coloration to the common dolphin, with gray, white and yellow along the flanks, and a white underside.

The Atlantic white-sided dolphin has a dark-gray stripe from the eye to the flipper, and a dark dorsal fin and flippers. They give birth to a single calf, after a gestation period of 11 months.

The white-sided dolphin can be seen off the coast in Barnstable and Essex, and the Island of Nantucket.

Bearded Seal

The bearded seal, also known as the square flipper seal is a medium-sized species of seal which is native to the Arctic Ocean. They are found in a wide range spanning from Bristol Bay on the Alaskan coast to the Sea of Okhotsk on the Russian Coast. They can also be found in Canada, Norway, and Japan. These earless seals are grayish brown and darker on the back. The bearded seal has been seen in Essex County in Massachusetts in 2002, but they will occasionally enter the waters around the state.

Females of this species are larger than males. On average, bearded seals measure about 2.1 to 2.7 meters in body length and their body mass spans between 200 to 430 kilograms. They are a major food source for polar bears. These seals feed primarily on small marine species including clams, squids, and fish.

Beluga
Beluga

Beluga Whale

The beluga is easy to spot due to its almost pure white, yellowish or pale gray color. They have no mottling on either side. They grow from 9.8-18 ft (3-5.5m) with a weight of 1,100-3,500 lbs. They have a gestation period of 12-14.5 months and give birth to one calf.

They eat a wide variety of fish, squid, octopuses and molluscs. They change color as they get older, with a pale gray at birth, then dark-brown to brownish-gray, then completely white at the age of ten years old.

They can be seen close to shore, and when stranded can generally survive until the tide comes back in. They have been sighted in waters off Barnstable, Bristol, Dukes and Essex counties.

Big Brown Bat

The big brown bat is an insectivore that eats mostly beetles, but also consumes other flying insects like moths, flies, and wasps. They live in all types of habitats, with a lifespan ranging from 18 to 20 years. This animal carries a lot of diseases, including rabies and parasites such as tapeworms and fleas.

The big brown bat is a small, nocturnal flying mammal. They live in colonies and uses echolocation to locate objects while flying at night. The color varies from brown to black. They measure from 11 to 13 cm, with a wingspan from 32 to 40 cm, and it weighs from 15 to 26 g.

The species of bat lives in North America, Central America, the Caribbean and the northern portion of South America. In Massachusetts they can be found all over the state.

Black-tailed Jackrabbit

The black-tailed jackrabbit is also known as the American desert hare and is common in the western regions of the United States and Mexico. They live at high elevations, up to 3000 meters above sea level. They generally measure around 61 cm in length and weigh about 1.4 to 2.7 kilograms.

Black-tailed Jackrabbit

Black-tailed jackrabbits are characterized by big ears which are black-tipped on the outer surfaces. Their fur is usually grayish-brown with white underparts. Females of this species tend to be larger than males. The diet of the jackrabbit is mainly made of shrubs, small trees, and grasses.

There are no populations of black-tailed jackrabbits on the mainland of Massachusetts. There was a population on Nantucket but it is unknown if there are any left.

Blainville’s Beaked Whale

A member of the beaked whale family, Blainville’s beaked whale, is medium-sized. They measure between 13.7-15.4 ft (4.2-4.7m) with a weight between 0.8-1.1 tons. They feed on deep-water squid and some fish. They are dark brown or blue-gray with a lighter underside.

This species of beaked whale has a flattened forehead, and the head at the blowhole is indented. They have a fairly long neck with an arched lower jaw. Blainville’s beaked whale is also known as the dense-beaked whale due to Hendi de Blainville stating that a piece of bone he had was the densest bone structure he had ever seen.

They are never seen close to shore in Massachusetts, but can be seen in coastal waters.

Blue Whale

The blue whale is the largest living animal to live on Earth, not just now but ever. This species of whale reaches sizes between 69-95 ft (21-29m), although they are slightly smaller in the Northern Hemisphere. Females are larger than males and can reach incredible weights of 90-150 tons.

Blue whale
Blue whale

The diet of a blue whale consists mainly of krill, with some crabs and squid. They are easy to spot because of their vast size, but they also have a flattened, broad, u-shaped head. Even though they are so large, they have a tiny dorsal fin which is set far back.

The blue whale is an endangered species in Massachusetts. They have been seen on the coasts off Barnstable, Essex, Suffolk and Norfolk counties, but are generally seen offshore.

Bobcat

The bobcat is a nocturnal and elusive, midsize wildcat from North America (related to the lynx). They look like a big domestic cat with a bobbed tail. Their color can range from grayish brown to red, with a white underbody. They measure from 47 to 125 cm and weigh from 8 to 9 kg.

The bobcat is a carnivore and eats raccoons, squirrels, rodents, rabbits, birds, reptiles, skunks, and sometimes even deer. They have an extraordinary night vision and can live in all types of habitats across the central section of North America. Their lifespan ranges from 10 to 12 years.

Although classed as least concern, bobcats are hard to spot in Massachusetts, with most sightings taking place in central and western counties of the state, but occasionally found in Bristol, Norfolk and Plymouth states.

Bobcat

Bottlenose Dolphin

The common bottlenose dolphin grows from 6.2-13.1 ft (1.9-4m). Their diet consists mainly of squid and small fish. They have a single calf with a gestation period of 12 months.

Bottlenose dolphin are gray to black, with a lighter underside and a dorsal cape. They have a short beak, with a mouthline that makes them look like they are smiling. The common bottlenose dolphin is the dolphin that you will most likely have seen in television or films.

They have been seen off the coast of Barnstable, Essex and Plymouth counties, and also the islands of Dukes and Nantucket.

Brown Rat

The brown rat is a rodent that lives all over the world. Their color is brown with a lighter color on the underbody. They measure from 15 to 28 cm and weigh from 140 to 500 g.

The brown rat is an omnivore, eaing seeds, nuts, grains, fruits, eggs, birds, mice, small rabbits, fish, and insects. They live in forests, areas with bushes, urban and suburban areas, with a lifespan of two years.

They can be found in every county in Massachusetts.

Canada Lynx

Cinereus Shrew

The cinereus shrew is also known as the masked or common shrew..  They are a small, nocturnal, and solitary animal.  Their color is grayish-brown with a lighter grayish color in the underbody. They measure about 9 cm, with a weight of just 5g and a lifespan of just 14 months.

The cinereus shrew is a carnivore and eats insect larvae, ants, grasshoppers, crickets, spiders, worms, snails, small rodents, and salamanders. They live in grasslands, forests, riverbanks, lakeshores, and tundra in the northern part of North America. Their lifespan is just 14 months.

The cinereus shrew is classed as least concern and can be found all over the state of Massachusetts.

Common Muskrat

The muskrat is the only species for the genus Ondatra. They are a medium-sized semiaquatic rodent found in wetlands in a wide range of climates and habitats. Their average measurements are about 40-70 cm in length, and they usually weigh around 0.6-2kg. Although commonly referred to as a rat, muskrats are a different kind of rodent.

The fur of the muskrat is thick and short of a dark-brown color. Their tails are covered with scales (not hair) which helps them swim rapidly and with ease. Muskrats spend the majority of their time in the water and can swim underwater for up to 17 minutes. This species usually lives in a group made up of a male and female and their offspring. Muskrats make nests to protect themselves from the cold and predators, usually as burrows with an underwater entrance.

In the state of Massachusetts, the muskrat can be found everywhere except the island of Nantucket County.

Coyote

The coyote is a midsize wild canine, with the look of a domestic dog, although they are thinner and smaller than the gray wolf. Their color is grayish-brown with a white underbody. They measure about 1.5 m (including the tail) and weigh from 6.8 to 21 kg.

coyote
Coyote

This highly adaptable omnivore has an extremely varied diet, which includes: cactus fruits, flowers, insects, rodents, rabbits, birds, and reptiles. They can be found in any habitat across North and Central America. Their lifespan ranges from 10 to 14 years in the wild and up to 21 years in captivity.

Coyotes can be seen in every county in the state except the island of Marthas Vineyard and Nantucket.

Cuvier’s Beaked Whale

Cuvier’s beaked whales grow between 18-23 ft (5.5-7m) with a weight between 2.2 – 3.9 tons. They feed on squid, fish and crustaceans. They generally have scarring and shark bits on the gray or reddish-brown body. They have a sloping forehead and a slight concave head.

Cuvier’s beaked whales are known to breach but will generally try to avoid boats, although they are one of the most-watched beaked whales. Although they may be seen alone, groups of seven may travel together. Groups of 25 have been seen together, although this is rare.

Although they have been found stranded in Massachusetts, they are not generally seen close to shore.

Dwarf Sperm Whale

The dwarf sperm whale measures just 6.9-8.9 ft (2.1-2.7m) with a weight between 300-600 lb. They are similar in looks to the pygmy sperm whale but have a squarish head, flatter back and a more prominent, pointed, erect dorsal fin.

The dwarf sperm whale has been said to resemble an upside-down surfboard when seen in the water. Dwarf sperm whales are usually seen laying motionless at the surface of the water. They eat squid and octopus, along with fish and crustaceans.  

They are rarely seen in Massachusetts, but occasionally can be seen off the coast of Barnstable, Essex and Nantucket counties.

Eastern Chipmunk

Chipmunk
Chipmunk

The Eastern chipmunk is a solitary animal. Their color is reddish-brown with two white stripes surrounded by black stripes on the side of its back and head, with a fifth black stripe running across the center of its back. The chipmunks underbody has a lighter brown color. They measure about 30 cm (including the tail) and weigh from 66 to 150 g.

The Eastern chipmunk is an omnivore that eats acorns, insects, eggs, mushrooms, snails, nuts, fruits, seeds, berries, and corn. They like to live in rocky areas, logs, and bushes in deciduous forests and urban parks. They live in the eastern United States and Southeast Canada, with a lifespan of three years.

The Eastern chipmunk has not been seen in Nantucket County but can be found in all mainland counties.

Eastern Cottontail

The Eastern cottontail is a solitary, mostly nocturnal rabbit that lives in the southeast of the United States, and parts of Central and South America. Their color varies from reddish-brown to grayish brown, with a white underbody. They measure about 37 cm and weigh about 1.2 kg.

The Eastern cottontail is a herbivore that eats various grasses, branches, bark, clover, fruits, and vegetables. Their habitat is mainly grasslands. Their lifespan is three years in the wild and eight years in captivity.

In Massachusetts, the Eastern cottontail can be found all over the state.

Eastern Gray Squirrel

The Eastern gray squirrel is a diurnal and solitary animal. The color varies from gray to grayish red, and the underbody is white. They measure from 23 to 30 cm (including the tail) and weigh 400 to 600 g.

The Eastern gray squirrel is an omnivore and eats nuts, acorns, insects, berries, bird eggs, and seeds. They have an expected lifespan of six years.

The Eastern gray squirrel is an adaptable animal that lives in the trees on the Eastern side of North America. They can be found in all counties in Massachusetts, and have been introduced into Nantucket County recently.

Eastern Mole

The Eastern mole is a solitary, midsize mammal from the eastern United States. Their color is dark gray. They measure from 14 to 18 cm and weigh from 40 to 50 g. This carnivore eats worms, insects, larvae, mice, bugs, and small birds.

Eastern moles live in grasslands and thin forests, with an expected lifespan of six years. The Eastern mole digs tunnels in search of food. Although they control the number of insects in a given location (preventing pests), the damage they cause in gardens makes people despise them.

Eastern Red Bat

The Eastern red bat is found across North America, and is a species of microbat.  They measure 109 mm (4.3 in) with a weight of just 7 to 13 .  They have pointed, long wings, short ears and a long tail. 

Eastern red bats are very maneuverable and can fly quickly.  They do not hibernate, chasing to stay in the same regions all year.  They are prioritized as least concern by the IUCN.  They can be found statewide in Massachusetts.

Eastern Red Bat

Eastern Small-footed Bat

The Eastern small-footed bat is a nocturnal mammal found in the eastern United States and southeastern Canada. Their face, ears, and wings are black, and the rest of the body is grayish brown. They measure from 6.5 to 9.5 cm, with a wingspan ranging from 21 to 25 cm, and weighs from 4 to 8 g.

The Eastern small-footed bat is an insectivore eating beetles, moths, mosquitoes, and flies. They live in forests with caves and rock formations adequate for roosting. Their lifespan is 6 to 12 years in the wild, hibernating in winter.

The Eastern small-footed bat is an endangered mammal on the IUCN red list, but can be found in Berkshire and Hampden counties.

Ermine

The ermine is a solitary weasel that lives in the northern part of the continent. Their color is dark brown on the back and white on the underbody during the summer. In winter, their color changes to almost pure white. They measure from 17 to 32 cm and weigh about 260 g.

Ermine is a carnivore that eats mainly rodents but sometimes will eat birds, fish, amphibians, small reptiles, and insects. They live in taigas and tundras, with a lifespan of 4 to 6 years in the wild. They can be found statewide except on the islands.

Ermine
Ermine

European Rabbit

The European rabbit is a small rabbit measuring 40 cm in length with a weight of 2.6-4.4 lb.  Their ears are large measuring between 6.5-7.5 cm in length. 

The rabbits are various colors, but generally gray-brown with hairs of black, gray or red on the body.  They are born with a white star shape on their foreheads but this fades by adulthood.  They live in warrens with other rabbits, generally up to ten.

There may still be some of this species on Boston Harbor islands.\ 

Fin Whale

The fin whale is a large whale growing between 59-88 ft (18-27m), although slightly smaller in the Northern Hemisphere. They reach a weight between 34-100 tons. There are several thousand of the species off the West Coast of America.

They have pigmentation on their heads that is different on both sides, which is rare for a whale. This is said to be to confuse their prey. They are the second-largest living animal on Earth after the blue whale. Populations of the fin whale can be seen almost year-round in the Gulf of California.\

The fin whale is listed on the IUCN red list as endangered, but can be seen off Barnstable, Essex, Norfolk and Suffolk counties.

Fisher

The fisher is a small, solitary, mainly nocturnal, aggressive, and elusive weasel. They are related to the American marten. Their color varies from dark brown to black, with a lifespan of seven years in the wild and, in rare cases, up to 14 years in captivity. They measure from 75 to 120 cm and weigh from 2 to 6 kg.

The fisher is a carnivore that eats mice, snowshoe hares, birds, cats, poultry, shrews, porcupines, and squirrels. Even though they move on the ground most of the time, they are an excellent climber.

They live in forests in the southern part of Canada and the northern and western part of the United States. In Massachusetts they can be seen in every mainland county.

Fisher

Gray Fox

The gray fox is a solitary canine that lives in the southern part of the United States, Mexico, Central America, and the northern parts of South America. Their back has a scattered combination of light and dark gray, the sides are reddish-brown, and the underbody is white. They measure from 76 to 112.5 cm and weigh from 3.6 to 7 kg.

The gray fox is an omnivore eats mice, birds, voles, rabbits, insects, corn, fruits, nuts, and berries. Their lifespan is 16 years in the wild and 20 in captivity.

They live in dense forests, in areas with rocky terrain or thick vegetation on the mainland except Suffolk County and the islands.

Gray Seal

The gray seal is a mammal that lives in huge groups on all the coasts of the North Atlantic Ocean. Their colors vary from gray to black or dark brown, and normally their skins are spotted. They measure from 1.95 to 2.3 m long and weigh from 170 to 310 kg.

The gray seal is a carnivore that eats fish, crabs, lobsters, shrimp, octopuses, squids, and seabirds. Their lifespan is 25 to 35 years.

Gray seals live on rocky coasts, floating sheets of ice, sandbanks, and icebergs. They can be found in Barnstable, Dukes, Essex and Nantucket counties.

Hairy-tailed Mole

The hairy-tailed mole is a midsize mammal found in the eastern United States and southeastern Canada. Their color is dark gray. It measures from 13 to 15 cm and weighs about 51 g. This insectivore eats worms, larvae, slugs, and ants. The hairy-tailed mole lives in deciduous and coniferous forests, and open areas. Their lifespan is up to four years.

They can be found in central, western and northeastern counties in the state.

Harbor Porpoise

The harbor porpoise is a small, shy, and elusive marine mammal, and is a relative to the dolphins. Their color is dark gray on top and a much whiter gray in the underbody. They measure from 1.4 to 1.9 m and weighs from 61 to 76 kg.

Harbor porpoise
Harbor porpoise

The harbor porpoise is a carnivore and mainly eats fish and sometimes octopuses and squids. They like to swim in shallow bodies of water and even frequents inland water bodies, like rivers and estuaries. Their average lifespan in the wild is about 20 years.

The harbor porpoise lives in the northern part of the Atlantic and Pacific Oceans (and in both the East and the West coasts of the northern part of North America). They can be seen off the coast of Barnstable, Bristol, Dukes, Essex, Nantucket, Norfolk, Plymouth and Suffolk counties.

Harbor Seal

The harbor seal is a marine mammal, also known as the common seal. Their color is brownish gray with light or dark spots, and the color is lighter on the underbody. They measure 1.85 m and weigh from 55 to 168 kg.

This carnivore eats squids, crustaceans, shrimp, crabs, mollusks, and fish. They live in the harbors of the Northern part of the world (and in both the east and west coasts of the northern part of North America). They are an excellent swimmer and have a lifespan of 20 to 35 years.

They are usually found in rocks, beaches, and glacier ice, rarely moving from too far, but if there is a danger, it rushes to deeper water. They can be seen in Barnstable, Bristol, Dukes, Essex, Nantucket, Norfolk, Plymouth and Suffolk counties.

Harbor Seal

Harp Seal

The harp seal is part of the earless seal species.  They can be found in the Atlantic Ocean and Arctic Ocean.  They have a fur of silver-gray, with black spots and jet-black eyes.  They grow from 1.7-2.0m and weigh from 115-145 kg.  Unlike other seals, the harp seal can dive to deep depths. 

They have been spotted at over 500m deep, and can hold their breath for up to twenty minutes.  Dive depth increases in winter when there is less food at shallow depths.

The harp seal has been seen in Barnstable, Dukes, Essex, Nantucket, Plymouth and Suffolk counties.

Hoary Bat

The hoary bat is a species of vesper bat found in most areas of North America and much of South America. This species usually ranges between 13 to 14.5 centimeters in length and weighs approximately 26 grams.

The hoary bat is the largest in Canada. They are characterized by dense and dark brown coat with white tips, from which the name comes. Females can be up to 40% heavier than males. These bats usually roost solitarily on trees, hidden by foliages. They live in coniferous forests and generally hunt over open areas or lake. They have a very long migratory pattern.

The hoary bat can be seen statewide throughout Massachusetts.

Hoary Bat
Hoary Bat

Hooded Seal

The hooded seal gets its name from an inflatable bladder on the head of the male.  The bladder hangs over the eyes and the lips when deflated.  The sac can inflate, which the seal can use when swimming to ward off other species when it feels threatened.  The males also have a membrane that comes out of the left nostril that produces sounds which they use to attract a mate, but mainly for singalling acoustically.

The hooded seal is an extremely rare sight in Massachusetts.

House Mouse

The house mouse is a secretive and cautious mouse that is sometimes domesticated. Their color is gray, black or brown with the lighter underbody. They measure from 7.5 to 10 cm (including the tail) and weigh from 40 to 45 g. The house mouse is an omnivore eating meat, fruits, seeds, and grains. Their lifespan is less than one year in the wild and from 2 to 3 years in protected environments.

The house mouse tends to live in places where humans live.The house mouse can be seen in every country except Martha’s Vineyard island.

Humpback Whale

The humpback whale grows between 46-56 ft (14-17m) with a weight between 28-45 tons. They approach whale-watching boars and are inquisitive. They are very popular with whale-watchers due to their breaching, lobtailing, spyhopping and flipper-slapping They have a gestation period of 11-12 months and give birth to one calf.

They can be seen in many places in North America, with Hawaii and Alaska as particularly good places to spot them. In Massachusetts they can be seen off the coasts of Barnstable, Essex, Nantucket, Norfolk, Plymouth and Suffolk.

Humpback whale
Humpback Whale

Killer Whale

The killer whale is also commonly known as the Orca, a name taken from its binomial name of Orcinus orca.  Killer whales are the largest members of the dolphin family, growing from 6 to 8 meters long and weight 5.9 tons.  Females are smaller than males.  They are one of the fastest marine mammals due to their size and incredible strength, reaching speeds ip to 56 km/h.  They have a black upper side with a white underside.

Orca’s can be seen off of Barnstable, Dukes, Essex and Nantucket.

Little Brown Bat

The little brown bat is a small North American bat. Their colors vary from light tan to dark brown, with a lighter color on its underbody. It measures from 8 to 9.5 cm and weighs from 5.5 to 12.5 g. This insectivore eats mosquitoes, moths, beetles, etc. Their lifespan is from 6 to 7 years.

They live in most of North America. They will find any place to roost during the day, such as trees, caves, and rocks. In winter, this bat hibernates in caves. They live over most of the state, although they are listed as endangered on the IUCN red list.

Little Brown Bat

Long-finned Pilot Whale

The long-finned pilot whale is a large and very social species of dolphin found in the North Atlantic Ocean and the Antarctic Ocean. Their color is normally black but can be dark gray or brown. They have a light gray mark from the eyes to the dorsal fin. The pilot whale measures from 3.7 to 6.7 m and weighs from 1,000 to 3,000 kg.

They are carnivores and eat turbot, squid, dogfish, hake, octopus, cod, and shrimp. Their lifespan is up to an impressive 45 years.

The long-finned pilot whale lives in cold, mild water, closer to the North and South Poles. In Massachusetts they can be seen rarely off the coast of Barnstable, Essex and Nantucket counties.

Long-tailed Shrew

The long-tailed shrew is a small shrew measuring 48 to 79 mm.  Their tail takes the total length to 120 mm.  They weight just 3.1 to 8.3 g.  Their long tail is used to help them balance when they climb in their rocky habitat.  They are gray to black in color.

They live in mountainous territories, around and under rocks or near streams. The long-tailed shrew is listed as special concern in Massachusetts, and can only be found in Berkshire County.

Long-tailed Weasel

The long-tailed weasel is a fearless, aggressive hunter. They are also called the bridled weasel or the big stoat. Their color is reddish-brown with a light yellow underbody. However, in cold, northern regions, they are completely white. It measures from 23 to 35 cm and weighs from 85 to 267 g.

This carnivore can attack animals that are twice its height. They eat mostly mice, voles, rabbits, chipmunks, birds, eggs, and insects. Their lifespan is up to five years.

The long-tailed weasel lives in grasslands and thin forests (sub-tropical areas with mild temperature) in the southern part of North America, in Central America, and the northern part of South America. They can be found all over the state except the islands of Dukes and Nantucket counties.

Long-tailed Weasel

Meadow Jumping Mouse

The meadow jumping mouse is a solitary and mostly nocturnal North American rodent. They can jump 8 feet or more when they are disturbed. Their color is light brown, with a thick dark brown stripe on its back and a white underbody. They measure from 18 to 24 cm (including the tail) and weigh from 11.5 to 35 g.

This omnivore eats mostly seeds, insects, and fruits. Their lifespan is less than a year in the wild, but up to five years in captivity.

The meadow jumping mouse lives mostly in the grasslands, thin forests and humid areas in the northern part of North America. They can be found all over the state of Massachusetts.

Meadow Vole

The meadow vole is a small, mostly nocturnal rodent. They are also called a field mouse or meadow mouse. Their colors vary from yellowish or reddish-brown to dark brown, and the underbody is gray. They measure about 12 cm and weigh about 43g.

This herbivore eats grasses, weeds, grains, seeds, bark, roots, and fruits. They are an excellent swimmer and very good at digging holes. Their lifespan ranges from 2 to 16 months. Some people consider them a pest because they cause great damage to plants. They also carry similar diseases to other rodents.

They live in dense grasslands and thin forests in the northern part of North America (except for the most intense polar regions). They can be found statewide in Massachusetts.

Moose

The moose is a solitary animal with huge antlers and is the largest member of the deer family. Their color ranges from light to dark brown. The moose is massive, measuring from 1.4 to 2.1 m in height and from 2.4 to 3.2 m in length. They weigh from 200 to 700 kg and are herbivores. They eat bark, leaves, pine cones, young branches, and fruits.

In Massachusetts they live in the counties in the central and western counties, but may also be found in Bristol and Plymouth. Moose lives in forests in the northern part of the continent, and have a lifespan from 15 to 25 years.

Moose
Moose

New England Cottontail

The New England cottontail is a rabbit found in the eastern part of the United States, from New York to Maine. They are one of the North American mammals. Their color is dark brown with small, scattered black dots and white underbody and tail. It measures from 39.8 to 43.9 cm and weighs from 995 to 1,347 g.

This herbivore eats grasses, leaves, wood, seeds, stems, flowers, fruits, bark, and forbs. It lives in young forests. Their lifespan is about three years in the wild. They are considered a vulnerable species, but they are still not endangered.

The New England cottontail is also referred to as the gray rabbit, brush rabbit or Cooney and is usually located in the areas of New England, from Maine to southern New York. In Massachusetts they are found statewide except on the islands. It is estimated that their current population is 85% less than what it was in the 1960s, which made the species “protected” under the Endangered Species Act.

Their weight is between 995 grams and 1347 grams, with a total body length of approximately 398-439 mm. These rabbits live in forests with dense and thick brush, preferably of blueberries. They like to live on a higher elevation, creating their depressions where they nest.

North American Deer Mouse

The deer mouse is a small and reclusive rodent. Their color (which resembles that of a deer) varies from gray to brown, and the underbody is white. They measure from 8 to 10 cm (without the tail) and weigh about 20 g. This omnivore feeds itself on a wide variety of foods, such as seeds, nuts, fruits, and insects.

Their lifespan is eight years in captivity and less than a year in the wild. They can carry viruses and bacteria that cause diseases to humans, such as Hantavirus Pulmonary Syndrome (HPS).

This species of deeromouse lives in many different habitats (forests, mountains, deserts, grasslands, tropical regions) throughout most of North America. They can be found in every county in Massachusetts.

North American Porcupine

The North American porcupine is also known as the common porcupine, and they are a rodent with black or brown fur with hairless feet to climb trees. They can be easily recognized by quills, that are solid at the tip and base and present around all its body, except for the stomach. The quills are used as a defense mechanism.

They are a herbivore, and they are often found climbing on trees to eat leaves. Their size makes it the second-largest rodent in North America. The head to body length is approximately 60-90 cm without counting the tail measuring around 14.5 up to 30 cm. Their weight is about 9 kilograms on average. 

The porcupine can be found in central, western and northeastern counties, but has also been seen in Barnstable and Plymouth counties.

North American River Otter

River otter
River Otter

The river otter is a smart, semiaquatic mammal from northern North America. It has short, very dense fur. Their colors vary from gray to brown, with a lighter underbody. It measures from 66 to 107 cm and weighs from 5 to 14 kg. This carnivore eats mostly fish, turtles, frogs, crayfish, and insects.

The otter lives in aquatic habitats in the northern part of North America. Their lifespan is 8 to 9 years in the wild and 15 to 20 years in captivity. The otter can be seen statewide in Massachusetts except in Nantucket or Suffolk counties.

North Atlantic Right Whale

The North Atlantic right whale is between 49-52 ft (15-16m), weighing between 34-78 tons. Females grow larger than males. They live mainly on krill and copepods. They are a slow swimmer but can be acrobatic. Their behavior includes lobtails, flipper-slaps and frequently breaches.

The North Atlantic right whale is very inquisitive and approaches boats. Their name comes from whalers who thought they were the right whale to catch. They have a single calf after a gestation period of 12-13 months. They have no dorsal fin, a dark body, and a very large head covered in patches of rough skin.

The right whale can be seen off the coast in Barnstable, Dukes and Plymouth counties. The North Atlantic Right whale is listed as endangered in the state.

Northern Bottlenose Whale

The Northern bottlenose whale is a medium-sized whale. They measure from 19-32 ft (5.8-9.8m) with a weight between 6.4-8.3 tons. They feed mainly on squid and shoaling fish. They are dark gray or brown with a cylindrical bottle. They have a forehead that is squared off behind the beak, which is tubelike.

These whales often approach boats and are quite curious. They have a single calf after a gestation period of 12 months.The Northern bottlenose whale is very rarely seen around Massachusetts.

Northern Flying Squirrel

The Northern flying squirrel is a nocturnal mammal that has a furry membrane between their front and hind legs which they use to glide from tree to tree. Their color varies from gray to dark brown, with white on its underbody. They measure about 16 cm and weigh about 140 g. This omnivore eats nuts, acorns, fruits, buds, fungi, insects, bird eggs, and lichens.

The Northern flying squirrel lives in forests in the northern part of the continent with a lifespan of four years. In Massachusetts they can be found in central and western counties in the state.

Northern Long-eared Myotis

Long-eared myotis

The Northern long-eared myotis is a bat in North America. It uses echolocation to navigate while flying. Their color varies from yellowish light brown to black. They measure about 8.6 cm and weigh from 5 to 8 g. This insectivore eats mostly moths, beetles, flies, and leafhoppers. Their lifespan is about 18.5 years.

They live in boreal forests (Taiga) in the eastern, central part of North America. The Northern long-eared myotis is listed as endangered in the state, but can be found in every county. They are an endangered species due to a sickness that is killing the species.

Northern Short-tailed Shrew

The Northern short-tailed shrew is a mammal found in the northern parts of North America. Their color is dark gray, with a lighter shade of gray on the underbody. They measure from 11 to 14 cm and weigh from 15 to 30 g.

This species of the shrew is carnivore eating insects, salamander, worms, mice, snails, seeds, voles, and fungi.

They can live in many habitats, including grasslands and deciduous and coniferous forests, with an expected lifespan of 1 to 3 years. The Northern short-tailed shrew can be found in Berkshire County. They are listed as a species of special concern.

Pantropical Spotted Dolphin

The Pantropical spotted dolphin has a slender body, with a narrow beak and whitish lips. There is a crease between the beak and the melon, and a dark stripe from the beak to the flipper. They grow from 5.2-8.5 ft (1.6-2.6m) with weights of 265 lb. They are heavily spotted on the sides with a gray cape on the dorsal side and a light underside.

The Pantropical spotted dolphin was one of the species caught most by tuna fisherman in the past. The spotted dolphin can be seen off the coast in Barnstable, Dukes and Nantucket counties.

Pantropical Spotted Whale

Pygmy Sperm Whale

The pygmy sperm whale grows between 8.9-12.5 ft with a weight between 700 -1000 lb. They eat squid and octopus, but will also eat crustaceans and fish. They leave behind a squid-ink like substance in the water when frightened or startled, leaving a cloud in the water.

They look similar to the dwarf sperm whale but have a small, hooked dorsal fin and are more rounded in profile. They have a small body and are sometimes mistaken for sharks.

Pygmy sperm whales are often stranded in places like Florida. Although rare in Massachusetts, they can be seen off the coast of Barnstable, Essex and Nantucket counties.

Raccoon

The raccoon is a mostly nocturnal midsize mammal from North America. Their color is gray, brown or black and its white face with a black area around its eyes is very characteristic. They measure from 40 to 70 cm and weigh from 5 to 26 kg.

This opportunistic omnivore eats fruits, plants, oak nuts, insects, worms, rodents frogs, nuts, eggs, and crayfish. The average lifespan of a raccoon is 2 to 3 years.

raccoon

Raccoons live in forests, suburban, and urban areas in the Central and southern part of North America. The raccoon can be found in all counties in Massachusetts except Nantucket County.

Red Fox

The red fox is a midsize canine that lives in the northern part of North America, Asia, Europe, and North Africa. The color varies from light yellow to red, with dark legs, and a white underbody. It measures from 45 to 90 cm and weighs from 2.2 to 14 kg. Their lifespan is from 2 to 5 years.

This omnivore eats grasses, fruits, corn, apples, oak nuts, cherries, berries, mice, birds, rabbits, squirrels, crickets, grasshoppers, beetles, caterpillars, and crayfish.

The red fox lives in forests, grasslands, mountains, deserts, and suburban areas. This species of fox can be found in all counties except on the islands of Martha’s Vineyard and Nantucket County.

Red fox

Red Squirrel

The red squirrel is a small, solitary, and diurnal animal of North America. Their color is gray, red or dark brown, with white on its underbody, and sometimes has black stripes on its sides. They measure from 28 to 35 cm (including the tail) and weighs from 200 to 282 g. This granivore animal eats mostly sunflower seeds and all types of nuts.

This arboreal animal lives in coniferous, deciduous, and mixed forests, with a lifespan of 5 to 10 years. The red squirrel can be found in all counties except those of Dukes and Nantucket.

Ringed Seal

The ringed seal is also known as the jar seal, netsik or nattiq and is a species of earless seal usually inhabiting the Arctic and sub-Artic regions. They are relatively small-sized seals, which rarely measure more than 1.5 meters in length.

The average dimensions span between 100 to 175 cm in body length and their body mass is usually between 32 to 140 kilograms. These seals are characterized by a distinct pattern of dark spots surrounded by light gray rings that give rise to their common name. 

Although listed as a Massachusetts mammal, they are extremely rare in the state.

Risso’s Dolphin

Risso’s dolphin looks completely different from any other species of dolphin. They are heavily scarred, either from squid or from each other when playing or fighting. They have a bulbous, large head with a beak that is not distinct.

Risso’s Dolphin

They have a crease on the front of the melon, with the dark dorsal fin, flipper and flukes. They are various colors, ranging from light white to dark gray. They are a large dolphin growing from 12.5-13.5 ft (3.8-4.1m) and weighing from 660-1,100 lb,

Risso’s dolphin are rare in the state, but can be seen off Barnstable, Essex and Nantucket counties.

Sei Whale

The sei whale is large, measuring from 39-52 ft (12-18m), weighing between 17-45 tons. The females are larger than males. There are no commercial whale-watching operations anywhere dedicated to watching this species. They do not gather in the same areas from one season to the next as most whales do, making them elusive.

They have a more varied diet than most other baleen whales which includes krill, copepods, crustaceans and schooling fish. They are mostly dark gray or brown, with a prominent dorsal fin.

The Sei whale is listed as endangered in Massachusetts, but can on occasion be seen off the coast of Barnstable and Essex counties.

Short-beaked Common Dolphin

The short-beaked common dolphin is also known as the common porpoise. Males are slightly larger than females with sizes between 5.2-8.9 ft (1.6-2.7m) and a weight of 155-440 lb. They are fast swimmers and can be seen bow-riding alongside ships.

Short-beaked Common Dolphin

Herds of this species can be seen in sizes ranging from 10 up to 10,000. They have a short beak with a dark cape with a ‘v’ shape under the fin. They have a white underside and yellow or tan patches on their sides.

The short-beaked common dolphin can be seen mainly off the coast of Barnstable, Essex and Nantucket counties.

Short-finned Pilot Whale

The short-finned pilot whale is medium-sized, growing from 12-23 ft (3.6-7.2m) and weighing between 1.1-3.9 tons. They are dark gray, brown or black with a gray patch behind the fin. They are stocky, with a round forehead and almost non-existent beak. They have a large dorsal fin which is set forward on the body but arches backwards. They typically travel in groups of 15-50 individuals, but groups of several hundred have been seen together.  

Although rarely seen in the state of Massachusetts, the short-finned pilot whale can be seen off the coast of the counties of Barnstable, Essex and Nantucket.

Silver-haired Bat

The silver-haired bat is a nocturnal, solitary mammal from the central part of North America. It uses echolocation when flying. Their color is normally black, but can sometimes be dark brown, with the tip of its fur gray. It measures about 10 cm and weighs from 8 to 12 g.

This insectivore eats flies, leafhoppers, moths, mosquitoes, beetles, bugs and ants. It lives in forests of North America. Their average lifespan is 12 years, and they migrate to warmer climates in winter.

The silver-haired bat can be found statewide in Massachusetts.

Smoky Shrew

The smoky shrew is a nocturnal mammal that lives in eastern North America. They normally use tunnels from other moles or shrews, but rarely dig their own. Their color is grayish-brown with a lighter underbody. They measure about 11 cm with a weight of 5g. This insectivore eats beetles, spiders, bugs, snails, insects, fungi, centipedes, worms, and larvae.

They live in coniferous and deciduous forests, marshes, swamps, and grasslands. Their lifespan is 14 to 17 months. The smoky shrew can be found in the central and western counties of Massachusetts.

Snowshoe Hare

The snowshoe hare is also called the varying hare or snowshoe rabbit, and it takes the name because of the large size of the hind feet. Their feet prevent these rabbits from sinking in the snow when hopping and walking. They are covered with fur on the soles too, for protection against freezing temperature.

Snowshoe hare
Snowshoe Hare

These rabbits turn white during the winter and rusty in the summertime. They can be distinguished by black tufts of hair on the edge of their ears and by the relatively small size of their ears compared with other hares. They usually measure about 36 to 52 centimeters and can weigh 1.3 to 1.7 kilograms as adults. They adapt their diet according to the season.

The snowshoe hare can be found statewide except the islands of Dukes and Nantucket counties. They usually feed on grass, fens, and leaves during the summer and turn to twigs and bark in the wintertime.

Southern Bog Lemming

The Southern bog lemming is a small mammal from eastern North America. The color varies from red to dark brown, and light gray on its underbody. It measures about 13 cm long and weighs about 35 g. This animal eats plants, seeds, stems, and leaves. Their lifespan is 29 months.

This particular species of lemming lives in grasslands, low moist places, deciduous and coniferous forests, wetlands, and marshes. The Southern bog lemming can be found in Franklin, Hampshire, Plymouth and Worcester counties, although they are listed as a species of special concern in Massachusetts.

Southern Flying Squirrel

The Southern flying squirrel is a nocturnal mammal that glides from one tree to the next because of membranes it has between its front and hind legs. They live in the western part of North America.

Their color is grayish brown, with a white underbody. It measures from 21 to 26 cm (including the tail) and weighs from 45 to 82 g. The Southern flying squirrel is an omnivore and eats nuts, seeds, spiders, acorns, fungi, eggs, insects, shrubs, buds, mushrooms, flowers, and fruits.

They live in deciduous forests, with a lifespan of five to six years in the wild and ten years in captivity. The Southern fling squirrel can be found in every county of the state except the islands of Dukes and Nantucket counties.

Southern Red-backed Vole

The southern red-backed vole is a mostly nocturnal, small mammal from the central part of North America. Its main color is gray, and they have a red stripe on their back, with an underbody of gray or white.

They measure from 7 to 11.2 cm and weighs from 6 to 42 g. This omnivore eats insects, grains, fruits, nuts, seeds, berries, leaves, roots, bark, fungi, and lichens.

This species of vole lives in coniferous, deciduous, and mixed forests near water bodies in southern Canada and the northern United States, with a short lifespan of just 10 to 20 months.  The Southern red-backed vole can be found in every state except the islands of Martha’s Vineyard and Nantucket counties.

Sowerby’s Beaked Whale

Sowerby’s beaked whale is a medium-sized whale with a body length between 13-18ft and weight between 1.1-1.4 tons. They do approach boats, with breaching, spyhopping and tail-slapping behavior.

They are blue-gray, gray or dark brown with an underside that is lighter. They have a small head for their body and a beak which has a straight mouth. They have a bulge in front of their blowhole and a small dorsal fin towards their rear.  

Sowerby’s beaked whale are rare in Massachusetts but have been seen off the coast of Barnstable Essex and Nantucket counties.

Sperm-whale
Sperm Whale

Sperm Whale

The sperm whale grows between 36-52 ft (11-16m) with a weight between 15-50 tons. They have a dark gray-body with a squarish head and a hump instead of a dorsal fin. Their blowhole is slit-like, and they can often be seen laying motionless at the surface of the water. They have a single calf after a long gestation period of 14-16 months. 

The sperm whale is listed as endangered in Massachusetts, and are rarely seen in the satte.

Star-nosed Mole

The star-nosed mole is a solitary mammal from eastern North America. Their color ranges from dark brown to black. They measure from 15 to 20 cm and weigh from 37 to 76 g. This carnivore eats worms, amphibians, aquatic insects, mollusks, and small fish.

They live in wet lowland areas, forests, and marshes. Their lifespan is 2.5 years in captivity. By using their star-nose, they gather a clear image of their surroundings. 

The star-nosed mole can be seen in all counties in the state except Dukes and Nantucket counties.

Striped Dolphin

The striped dolphin takes their name from the dark stripes that run down the sides of their bodies. They have a gray or blue-gray cape on the dorsal side, with stripes from the eye to the flipper along their sides. They can have stripes with colors of pink and blue on their sides as well. They grow from 5.9-8.9 ft (1.8-2.7m) and weight from 200-360 lb.

They have some amazing behaviors, able to leap up to 23 ft, with belly flops and somersaults seeming no trouble. They also roto-tail when they come out of the water. This involves moving their tails in circles as they leap out of the water.  

The striped dolphin is another rare dolphin in the state of Massachusetts, but when seen, is normally off the coast of Barnstable, Essex and Nantucket counties.

Striped Skunk

The striped skunk is a mostly nocturnal mammal found in the central part of North America. Their color can be black, gray, or brown, and it always has a white stripe on its back running from its head to its tail. It measures from 52 to 77 cm and weighs from 1.8 to 4.5 kg.

Striped Skunk

This omnivore eats crickets, grasshoppers, beetles, caterpillars, mice, voles, eggs, and small birds. Their lifespan is seven years.

The skunk lives in open areas, such as grasslands or thin forests in southern Canada, the United States, and northern Mexico. The striped skunk can be found in almost every county in Massachusetts except Nantucket.

Tri-colored Bat

The tri-colored bat is a small, nocturnal mammal found in eastern North America and Central America. It’s one of the native North American mammals. Their colors range from yellowish-brown to reddish-brown. They measure from 30 to 35 mm and weigh from 4 to 10 g.

This species of bat is an insectivore eating moths, midges, flies, beetles, mosquitoes, and ants. Their lifespan is 4 to 8 years in the wild. It is possible that they could become an endangered species.

They live in partly open places with large trees in forests, grasslands, urban and suburban areas. The tri-colored bat is listed as endangered in Massachusetts but can be seen statewide.

True’s Beaked Whale

True’s beaked whale measures between 15.7-17.7 ft (4.8-5.4m) with a weight between 1.1-1.5 tons. They feed on squid and some fish. There have only been a few sighting so very little is known about their behavior. They are brownish-gray or bluish-gray with a lighter underside. They are a medium-sized whale with a spindle-shaped body. They have a dark patch around each eye and a short beak. They have a bulbous head, and at the blowhole is an indentation. They have a dorsal fin which is short.

True’s beaked whale is rare in Massachusetts and is not seen close to the shore.

Virginia Opossum

The Virginia opossum is the only marsupial found in North America, but they can also be found in Central America. This medium-sized animal measures between 13-37cm in length and can weigh between 0.3-3.7 kg). It has rather short legs and typically gray or brownish fur. This animal is known to act as if they are dead as protection against predators.

Virginia Opossum

Their habitats can vary, but they prefer living close to water sources. They can also thrive in urban areas. The Virginia opossum can be found in all counties in the state except Dukes and Nantucket counties.

White-beaked Dolphin

The white-beaked dolphin is very large for a species of dolphin. They can grow from 7.9-10.2 ft, weighing from 400-770 lb. They have white, black and gray marking, with their tail usually paler. They have a white patch on each side. Their flippers are mostly dark, with a brown or gray beak. They can be found in St Lawrence River, the Gulf of St Lawrence and around Newfoundland.

The white-beaked dolphin is seen only rarely in the waters of Massachusetts, mainly off the coast of Barnstable and Essex counties.

White-footed Deermouse

The white-footed deermouse is a timid, nocturnal mammal that lives in eastern North America. Their color is reddish-brown, with a dark, broad mark on its back and white on the underbody. It measures from 9 to 10 cm (without the tail) and weighs from 20 to 30 g. This omnivore eats seeds, nuts, grain, insects, fungi, and fruit.

The deermous lives in warm, dry forests and semi-desert areas. Their lifespan is one year in the wild. The white-footed deermose can be found statewide in Massachusetts.

White-tailed Deer

The white-tailed deer is a mammal found in the central part of the American continent. In North America, they live in most of Mexico and the United States and the southern parts of Canada. Their color is grayish-brown in the winter and reddish-brown in the summer. They have patches of white on their face, underbody, and tail.

White-tailed Deer

This species of deer measures from 95 to 220 cm and weighs from 45 to 68 kg. This herbivore eats grass, corn, leaves, nuts, twigs, fruits, and fungi. Their lifespan is 4 to 5 years.

They are very adaptable to their environments and lives in grasslands, forests, farmlands, and deserts. The white-tailed deer can be found all over the state of Massachusetts.

Woodchuck

The woodchuck is a solitary, diurnal rodent. Their color is grayish brown. It measures from 41 to 68 cm (including the tail) and weighs from 2 to 6.3 kg. This herbivore eats mainly wild grass, roots, leaves, barks, nuts, flowers, fruit, vegetables, and farming crops. They sometimes eat insects like grasshoppers and snails. Their big front teeth never stop growing and feeding themselves constantly wears them out, keeping them at the correct size. Humans consider the groundhog a pest because it eats voraciously in the warm months of the year.

They hibernate from October to March, and have a lifespan of 6 years in the wild and up to 14 years in captivity.

They are found in flat, open pieces of land (like low-elevation forests, and grasslands) in the northern part of North America. The woodchuck can be found in all counties in the state of Massachusetts except Dukes and Nantucket county.

Woodland Jumping Mouse

The woodland jumping mouse is a medium-sized rodent with females being slightly larger than males. The average weight is about 17-35 grams with a length of 205-256 mm (including the tail). They can jump as high as 3 meters (or 9.8 feet) by leveraging their strong feet and long tail. Usually, they prefer a quadrupedal walk to move around. They are mainly nocturnal and prefer forested habitats. The fur of this mouse has several shades of brown, with white feet.

The woodland jumping mouse can be found in Worcester County and the counties to the west, of Berkshire, Franklin, Hampden and Hampshire.

Woodland Vole

The woodland vole is a mammal that lives in the eastern part of the United States. Their color is light or dark brown, with a white or gray underbody. They measure from 83 to 121 cm and weigh from 14 to 37 g. Their lifespan is a short three months.

This herbivore eats roots, nuts, seeds, and leaves, and lives in deciduous forests. The woodland vole can be seen in every county in Massachusetts except on the islands of Dukes and Nantucket counties.

Source: Massachusetts Government Website

https://www.mass.gov/service-details/mammals-in-massachusetts

Bryan Harding

Bryan has spent his whole life around animals. While loving all animals, Bryan is especially fond of mammals and has studied and worked with them around the world. Not only does Bryan share his knowledge and experience with our readers, but he also serves as owner, editor, and publisher of North American Mammals.

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