In Massachusetts, the Timber Rattlesnake is a native state-listed Endangered Species with only five surviving populations spread out from the New York border in the southern Berkshires, east to the Blue Hills near Boston. This particular snake has experienced the greatest modern decline of any native reptile and is a high conservation priority species for the Division of Fisheries and Wildlife (MassWildlife), the agency with the legal responsibility and mandate to conserve endangered and common fish and wildlife species. As part of an overall rattlesnake conservation strategy, MassWildlife is proposing to establish a small group of rattlesnakes on Mount Zion, a large island closed to public access at the Quabbin Reservoir located in central Massachusetts. Quabbin Reservoir is owned and managed by the Department of Conservation and Recreation’s (DCR) Division of Water Supply Protection. The Quabbin Reservoir is the site of MassWildlife's well-known and successful American Bald Eagle restoration project.
Population Status and Threats
Not only has the Timber Rattlesnake declined in Massachusetts and throughout New England, it is now completely extirpated (eliminated) from Maine and Rhode Island. Humans are the greatest threat to Timber Rattlesnake. In Massachusetts, the Timber Rattlesnake has lived continuously since long before European settlement, and has persisted in the face of sometimes intense persecution, but its decline over the past 30 years has been more severe than any other time in history. It is quite remarkable that these snakes have survived in Massachusetts at all. At least two Massachusetts populations have disappeared in recent decades, and of the five remaining populations, two are in immediate jeopardy. The conservation of this species is now a high conservation priority. While killing or disturbing a rattlesnake is a serious criminal offense, these acts, combined with road mortality continue to be major factors that contribute to the species imperiled status. Today, most of the surviving populations of Timber Rattlesnake are living in state parks, forests, and MassWildlife lands that are heavily used by the public. While the public has not been harmed, the snakes have been severely impacted. The proposal to establish a small discrete population of Timber Rattlesnakes on an island in Quabbin Reservoir has evolved out of the need to provide at least one location in Massachusetts where this native endangered species can avoid people. Several areas, including some of the islands are quite large and provide suitable habitat for a small but secure population to persist.
Similar to MassWildlife’s successful endangered turtle restoration program with Northern Red-Bellied Cooters, juvenile snakes from Massachusetts will be “headstarted” in captivity by the Roger Williams Zoo in Providence, Rhode Island. Each juvenile snake will be kept over a period of two winters to allow them to grow to a size that deters predators. The young snakes to be released on Mount Zion will be equivalent in size to a four or five year-old wild snake with a much higher probability of survival. Massachusetts populations are so small that it will be difficult to obtain very many new-born snakes to headstart. Releases of young snakes is expected to be in the range of only one to ten in any given year. In the southern Appalachians, a healthy rattlesnake population may be as high as 150 individuals, however here in Massachusetts, our populations are generally much smaller.
Habitat Needs and Snake Movements
The location proposed for this project is Mount Zion, the largest island in Quabbin Reservoir and off-limits to the public. At approximately 1,350 acres in size and 3.64 miles in length, this island is comparable to the habitat areas currently occupied by Timber Rattlesnake populations in other parts of the state, providing enough space to support a small but healthy population. The habitat is dominated by undisturbed hardwood forest, but is varied and appears excellent compared to other occupied Massachusetts sites. It is also very good habitat for the snake’s most common prey species, the White-footed Mouse and Eastern Chipmunk. Although there are no specific historic records of rattlesnakes occupying den sites on Mount Zion. The site was almost certainly occupied by rattlesnakes sometime in the past.
Mount Zion is large enough that the snakes would have little motivation to leave. The south end of Mount Zion Island is connected to the mainland by a one-lane causeway and the connection to the causeway is about 3.2 miles south of the proposed release site. In Massachusetts, Timber Rattlesnakes usually remain year-round within about two miles of the traditional den site, but individuals do occasionally disperse up to four miles away. In the unlikely event that a rattlesnake did cross the 0.3 mile long causeway, it would still be in an area with far less human activity than nearly all of the other Massachusetts rattlesnake populations. While rattlesnakes are perfectly good swimmers, their survival depends on access to unusually deep hibernation sites (hibernacula), usually in a rock talus or boulder field below a ledge, or a deep fissure in bedrock. These special habitats are scarce on our landscape. Any snake that leaves the island whether by water or over the causeway will not be able to find a suitable hibernation site and if unable to return will die over the winter. For the first decade of this project, the snakes will have radio transmitters to provide MassWildlife with important information about rattlesnake behavior, habitat use, and movement.
Rattlesnakes and People
Throughout human history, snakes of all types have been feared, maligned, and persecuted. Because the Timber Rattlesnake is venomous, people express understandable concerns for personal safety and the safety of family members, pets, and livestock. As a venomous snake, the Timber Rattlesnake certainly has the potential to be dangerous, but the reality is that there has been no harm inflicted on the public by these reptiles. Timber Rattlesnakes are generally mild in disposition and often rattle their tails to alert animals and people of their presence. Wild bites to people are extremely rare. Almost all bites occur as the result of irresponsible (and illegal) activities that involve someone deliberately handling or harassing the animals. The latest antivenin treatments have greatly reduced the danger even when a person is bitten.
Partnering in Snake Research & Conservation
Since 2006, scientists have found Timber Rattlesnakes with a sometimes fatal fungal skin disease. This emerging disease has now been documented in over a dozen species of snakes and is a new threat to Timber Rattlesnakes across their range. There is growing reason to fear that this fungal skin disease is a newly emerging threat to imperiled populations of snakes, including the Timber Rattlesnake. MassWildlife has taken a lead role in responding to this threat and in 2013, and was successful in obtaining $500,000 for a grant involving partners from state wildlife agencies, federal agencies and other conservation oriented organizations and institutions for a nationally competitive State Wildlife Grant for endangered species that will continue through 2016. The award will fund studies of this new disease as well as conservation management actions designed to enhance snake survival and increase the viability of imperiled snake populations.
The partners include eight fish and wildlife agencies: Connecticut, Illinois, Massachusetts, New Jersey, Minnesota, Vermont, Tennessee, Wisconsin, and eight other organizations and agencies, including the U.S. Geological Survey’s National Wildlife Health Center, Roger Williams Park Zoo, University of Massachusetts at Amherst, University of Illinois at Urbana-Champaign, the Wildlife Conservation Society at the Bronx Zoo, and the Orianne Society.
The Timber Rattlesnake in Massachusetts’ History
The Timber Rattlesnake figures prominently in the Commonwealth’s early history as a symbol of strength. In 1622, Chief Canonicus of the Narragansetts sent arrows bound in a rattlesnake skin (likely from the Blue Hills) to Governor Winthrop in Plymouth as a challenge for war. The Governor returned the rattlesnake skin filled with powder and shot with a message of defiance.
The familiar Gadsden Flag with a coiled Timber Rattlesnake and the words “DON’T TREAD ON ME” was designed in 1775 for use in the American Revolution and was later used by the Continental Marines. There is no doubt that the Timber Rattlesnake is seriously imperiled, and the Division of Fisheries and Wildlife the agency with the legal mandate and scientific expertise is working hard to ensure that this imperiled and fascinating snake does not finally disappear almost 400 years after European settlement.
Timber Rattlesnake Factsheet
One-page Timber Rattlesnake Brief