New England Cottontail Rabbit

New England Cottontail Rabbit

A New England cotton tail rabbit is released at Ninigret.
A New England cotton tail rabbit is released at Ninigret.

The rare New England cottontail, a threatened species of native rabbit once abundant throughout the New England region, is getting much needed help.  Biologists from the New England Cottontail Captive Breeding Working Group (NECCBWG) (see right) have teamed up to restore populations by breeding these rabbits in captivity and releasing them in natural habitat.  This program has made promising progress toward boosting cottontail numbers while the partners also work to protect and restore habitat throughout the range of this species.

Why is this rabbit endangered?

In the 1930's   non-native Eastern cottontail was introduced from Missouri primarily to benefit hunters when the native cottontail populations began to decline.  While the non-native Eastern cottontail population is widespread and abundant, the native New England cottontail has declined perilously since that time, according to biologists. Currently, the species is believed to be extirpated from Vermont, with sparse populations throughout the rest of New England.  Recent population surveys conducted by staff wildlife biologists from RIDEM’s Division of Fish and Wildlife and USFWS so far have documented only two occurrences of a New England cottontail in Rhode Island.

What is being done to save this species?

For a number of years, biologists have been monitoring existing populations and surveying for additional ones, while working to recreate suitable habitat. Zoo scientists together with regional partners formed the Captive Breeding Working Group as one potential solution for saving the New England cottontail. Members of the Working Group continue to inform and guide the process of transition from the breeding phase through repopulation efforts.

By 2010, Roger Williams Park Zoo had dedicated space, staff and veterinary care for the breeding program and continues to provide expertise to sustain a supply of healthy captive born rabbits for the reintroduction and population augmentation initiative. Partners in Connecticut, Maine and New Hampshire continue to provide wild adult cottontails for the breeding program. These are the “founder” rabbits that produce the offspring for reintroduction efforts and population augmentation. Genetics testing performed at the University of Rhode Island confirms the founders are indeed New England cottontails before they are added to the breeding program.

“To try to rebuild a species, we first needed to learn if we could keep healthy individuals in captivity,” said Lou Perrotti, Director of Conservation Programs at RWP Zoo. “We’ve learned that we can. We’ve also learned that we can successfully breed wild animals in captivity and raise the young from birth through weaning. Now, we are testing whether the captive born babies can be released to a wild setting and survive the winter, and  produce self-sustaining and growing populations.”

Results to Date

In November 2011, the offspring, or kits, of the first founders were released at age three to four months at Ninigret National Wildlife Refuge in southern Rhode Island. They were placed in a one-acre habitat surrounded by predator-proof fencing to allow them to become acclimated to a natural environment without predation pressure. The offspring spent their first winter adjusting from living at the Zoo to living in the wild, learning to forage and fend for themselves in a predator-free environment. In March of 2012, some of the rabbits were fitted with radio collars and released into the wild on Patience Island, in Rhode Island’s Narragansett Bay so researchers could monitor their activity and health on an ongoing basis. Other captive-born rabbits were brought back to the Zoo and added to the breeding group. Additional groups of kits were released in July and September onto Patience Island. A small group also was sent to Great Bay, New Hampshire to build new populations and augment declining populations in that state. As of November 2012, more than half of the radio fitted rabbits were still alive, which meant they were successfully foraging and avoiding predators. The partners celebrated this as a successful result for a prey species. During 2013, the breeding and release program grew significantly, nearly doubling numbers achieved in each of the previous years, with young rabbits released both in Rhode Island and New Hampshire to augment those populations.

What is the future of this project?

This collaborative project aims to help restore sustainable cottontail populations. “The range-wide effort to save this native animal depends on the expertise and collaboration of partners like those involved in this project,” says Anthony Tur, Endangered Species Specialist with the US Fish and Wildlife Service. “Thanks to the dedication of the zoo staff and others, we are now prepared to expand the program to achieve meaningful conservation goals for the cottontail.”

The Working Group partners aim, first, to expand and manage the early successional habitat needed for this species, working in some cases with private landowners. Second, the captive breeding program will continue, with the Zoo aiming to significantly increase the number of captive born produced each year. In 2011, 11 rabbit kits were captive born. That number rose to 28 in 2012 and 42 in 2013. To date, 60 young rabbits have been introduced to the wild in Rhode Island and 21 have been released in New Hampshire. With the help of the Rhode Island Foundation, who provided $15,000, and federal funding secured through a regional conservation needs grant, the breeding facilities are being expanded in 2014. Perrotti hopes this larger capacity will result in a significantly higher birth rate each year going forward