The Mammals of New York State
by Roland Kays and Joe Bopp, New York State Museum, CEC 3140, Albany, NY 12230

A moose crosses an Adirondack road and traffic stops. Fearful campers scrutinize a black bear as it moves through their campsite. Even a mouse scurrying across the ground in the back yard will attract notice. Mammals command attention. Except for a few common species, most of New York’s 103 mammal species are rarely seen. When they do show themselves, it can be quite exciting.

Mammals arouse our emotions, often in contradictory ways. The fluffy gray squirrel is awfully cute, until it nests in your attic. The charismatic wolf is a majestic symbol of wilderness, until it threatens your livestock. Depending on your point of view, a white-tailed deer is a precious little Bambi, a trophy to be mounted on the wall, a hunk of meat to be sizzling on the grill, a pest that won't leave your garden alone, or a 300 pound roadblock that could jump in front of your car at any moment.

These anthropomorphic views are obvious, but the less obvious ecological duties fulfilled by the state's mammals may be more important. The diverse ways in which they make a living means that they play a myriad of ecological roles that are at the very core of a healthy environment. Granivorous mammals (e.g., gray squirrel & white-footed mouse) eat seeds, killing many potential plant offspring. But they also disperse some seeds away from the shade of the mother plant unharmed and into a good environment for germination. Thus they sometimes act as a friend of the plant, sometimes as a foe. Folivorous mammals (e.g., white-tailed deer, Eastern cottontail) eat the leaves of plants and can keep certain species from overgrowing an area. Carnivorous mammals (e.g., weasel, bobcat, killer whales) keep their prey populations in check by eating the most abundant species. Predators can actually increase prey diversity by preventing a single species from becoming overabundant and driving others out. Insectivorous mammals (e.g., bats and shrews) help control insect populations, including many pest species. New York's diverse and abundant mammal fauna are an important, well integrated part of the state's varied ecosystems.

Give the size of New York State, its not surprising that we have more mammal species than other states in the North East. Our large state includes habitats typical of more southern states as well as classical northern boreal forest. Furthermore, the Long Island coastline provides access to a number of whale, dolphin, and seal species.

Many of the most familiar species in the state are widespread in a variety of different habitats, and occur throughout the eastern United States. Examples of these ubiquitous animals include both conspicuous and secretive species: groundhog, eastern chipmunk, gray squirrel, raccoon, mink, white-tailed deer, white-footed mouse, deer mouse, meadow vole, little brown bat, big brown bat, and eastern pipistrelle. A more select group of species are found in certain areas of NY and surrounding states, but are considered endemic to the North Eastern United States because they are found now where else. These include the New England cottontail, rock vole, long-tailed shrew, smoky shrew, hairy-tailed mole, and eastern small-footed bat. A few boreal species reach their southern limit in or near NY, especially in the Adirondack Mountains, including the northern flying squirrel, moose, and American marten. Southern species that stretch northward into our state include southern flying squirrel, least shrew, Virginia opossum, and Seminole bat. Off the Long Island coast 31 species of marine mammals are possible, including the largest living mammal, the blue whale, 12 dolphin species, and five seal species. Many of these whales and dolphins are almost never seen because of their rarity, shy nature, and the immensity of their ocean habitat.

Conservation

Like the rest of the Eastern United States, NY lost a number of mammal species to human exploitation, predominantly in the 18th and 19th centuries. Species that were considered dangerous, such as the gray wolf (eliminated by 1890) and cougar (last one shot in 1908), were removed with the encouragement of government bounties aimed at reducing the loss of livestock to native predators. Species that were especially valuable because of their meat or fur were trapped or hunted out: elk (hunted out in 1830's), Canadian lynx (eliminated in 1890's), wolverine (disappeared before 1840), moose (hunted out in 1860's). These extirpated species all went extinct in NY, although they retained populations in other parts of the country. Wildlife regulations were implemented in the state in the early 20th century, just in time to save a number of species that had been persecuted to alarmingly low levels, including the fisher, marten, American beaver, and white-tailed deer.

These protective measures permitted a recovery of these decimated mammal populations. This rebound was slow at first, but by the turn of the 21st century Adirondack marten populations were healthy, fisher had spread throughout eastern NY and began moving west, and beaver and white-tailed deer have became a pest throughout the state. One of the most exciting successes has been the recovery of the moose in the state. In the early 1980’s a few moose began to wander into the Adirondacks from Vermont. These vagrants established a resident population, and breeding was first recorded in 1990. The moose population continues to expand into the 21st century.

The modern conservation world has not been silent about the extinct large mammals of NY.

From 1989-91 a group attempted to restore Canadian lynx to the Adirondacks. Unfortunately, none the animals released in the high peaks remained in protected areas, and most were either killed by cars or lost as they dispersed outside of the park. Recently, groups have proposed the reintroduction of gray wolf and elk. These are both controversial projects. Wolves are feared because of the potential damage they would do to deer herds and livestock. Large herds of elk are known to cause significant crop damage, and may be a danger to auto traffic. However, the reintroduction of both would bring the mammal community closer to its original makeup, and be a big step towards the continued rewilding the state.

The only mammalian extinction in recent time is the sad story of the Allegheny woodrat. This harmless rodent attracted the affection of all that worked with it because of its big eyes, long whiskers, furred tail, large rounded ears, soft gray fur, and mild mannered disposition. This squirrel sized rat lived in rocky areas with abundant boulders and crevices, and little vegetation. The extinction of this mammal was not caused by direct human persecution or habitat destruction, but indirectly by our subsidization of the raccoon. Human settlement reduces the predation pressure on raccoons, and often provides new food sources (e.g., garbage); thus raccoon populations across the state have grown to abnormally high levels. Raccoons are not big predators on woodrats, however, a parasite called the raccoon roundworm (Balyisascaris procyonis) is deadly to the woodrat, but not raccoons. The eggs of the parasite are contained within raccoon feces and contaminate the woodrat's habitat when the feces decompose into the soil. Thus, the abnormally high populations of raccoons appear to have driven woodrats to extinction in NY, by way of this roundworm parasite. The last NY woodrat was captured in 1987. This species survives in a few other states (e.g., Pennsylvania), but remains critically endangered because of universal increase in raccoon populations.

Future extinctions are not out of the question, and conservationists are working hard to prevent them. New York lists ten mammals as "endangered", one as "threatened", and three are classified as "special concern". Combined, these conservation risks represent 14% of the total mammal fauna, (22% of the marine mammals and 10% of land mammals). Most (6) of the endangered species in NY are whales. Their fate largely depends on the continued ban on international whaling, and New Yorkers interested in saving the whales should support a continued ban on whale hunting. Three endangered species are presently extinct in the state (Allegheny woodrat, gray wolf, cougar), and will only be recovered with intense restoration efforts and widespread public support. The remaining endangered species is the Indiana bat, which is known to spend the winter hibernating in only eight caves in the state. Hibernating bats are especially sensitive to disturbance by unknowing spelunkers, and continued state protection of caves is needed to save this species from extinction. Because of this protection, Indiana bat populations have increased in recent years. The three species of special concern (eastern small-footed bat, New England cottontail, and harbor porpoise) are difficult to study, and their distribution in the state is poorly known. Overall, continued forest protection will be the most effective conservation strategy to protect our endangered terrestrial mammals, and prevent others from joining their ranks.

Invasive Species

NY harbors at least seven invasive species that were not parts of our original mammal fauna. The Norway rat, black rat, and house mouse (all native to Europe) live in close association with human habitations and garbage, and probably have little effect on natural habitats. The Norway rat may be driving the black rat out of some areas, but this situation has not been studied in detail. The black-tailed jackrabbit (native to South West USA) survives in the immediate J.F.K. Airport area after apparently escaping from a shipping box en route to a game farm in the 1950's. The European hare was introduced to a number of areas in the state, but may no longer survive. There have been two records of nutria (native to Brazil) in the state, but this species is not likely to establish itself here because of its intolerance of cold temperatures.

Without a doubt, the coyote has been the most successful invasive mammal in NY. This denizen of the western plains was first recorded in the state in 1925. It slowly increased in abundance and may not have had a secure breeding population until the 1960's. Coyote population growth appears to be ongoing, and they are now known from every part of the state except Long Island. One even showed up in Central Park! This remarkable invasion may have limited harmful ecological effects because the coyote appears to be largely filling the niche vacated by the extinction of the wolf. In fact, some biologists believe the canid presently roaming NY's forests is a hybrid between wolves and coyotes. This may help explain why eastern coyotes regularly feed on deer while their smaller western cousins do not.

Presently, invasive mammalian species are not a large conservation problem in the state, especially when compared with the damage caused by certain invasive fish, plants, or microbes. This is good fortune for NY, as exotic mammals are wrecking havoc in other parts of the world. Thus, we must remain vigilant to prevent other exotic introductions into the state that may be more damaging.

Our Information Needs

Our knowledge of the distribution of NY mammals largely comes from scattered research projects and inventories. Areas that have received specific attention include Otsego and Schoharie counties (late 1950's), Tug Hill (1960's), Long Island (late 1960's), the Capitol District (early 1990's), the Ithaca area, the Adirondacks, and the Catskills. This leaves many areas completely unsurveyed, and many more unknown in recent times. No state-wide mammal surveys have been done as they have for birds, reptiles and amphibians. This unsatisfactory situation means that much of what we know about our mammals is based on outdated information, or more recent anecdotal reports. A comprehensive survey would be difficult because of the variety of techniques needed to detect all 103 mammal species. Nonetheless, updated distribution data would be very valuable in identifying secretive species that may be in decline, and to document the expansion of pest or game species.

The recent spread of lyme disease and West Nile virus, both of which reside in wild mammals during part of their lifecycle, has spurred a much needed increase in research on the mammal - human disease connection. Certain species deserve special research attention for other reasons, especially the four extant species classified as "endangered" or of "special concern" (Indian bat, eastern small-footed bat, New England cottontail, and harbor porpoise). They have received this classification, in part, because we know so little about their distribution and natural history. Other difficult to capture species that may be more abundant in the state than is now presently recognized include the least weasel (two records from Chautauqua county) and Seminole bat (1 state record). New techniques such as fecal genetic analyses & remote bat detectors may help future field biologists meet this research need. Most marine mammals are also poorly understood. It is important to continue the present efforts to carefully preserve and study each specimen that washes ashore. Mammals populations that are obviously increasing in the state also deserve special attention. What are the prospects for a full moose recovery? How widespread are fisher? What is the effect of coyote expansion on prey and competitors? There are plenty of questions awaiting mammalogists in New York State.