Helping Connecticut’s Native Cottontail Rabbits

By Andrea Petrullo, Connecticut Department of Energy and Environmental Protection

There's plenty of good news out of Connecticut, where conservationists are working hard to help New England cottontails and other young forest wildlife sharing the habitat with the state’s native cottontail rabbit.

Rabbit Leavings

Throughout most of New England and eastern New York, biologists, field technicians, volunteers, and private landowners have joined forces in a regional monitoring program to locate populations of New England cottontails.

The protocol involves visiting a roughly 10-acre plot in the winter, preferably 48 hours or more after snow has fallen, and searching for rabbit droppings. Cold winter temperatures keep the fecal pellets fresh, and the snow makes them easier to find.
NEC map for Connecticut
Technicians or volunteers walk five transects through each plot, collecting pellets in vials and noting the coordinates where each sample was found. They also record information about the habitat itself: the percentage of the ground that is covered in shrubs, and the percentage on which a tree canopy is present.

The pellets are then sent to specialized laboratories, where DNA analysis reveals whether they were deposited by eastern cottontails (an introduced species) or native New England cottontails.

In Connecticut, a team of six field technicians participated in regional monitoring during the winter 2016-2017 field season. Sometimes joined by college interns or volunteers, they braved the cold and the densely tangled, thorny thickets to collect pellets. Of the roughly 3,100 pellet samples sent from the six-state region where New England cottontails are found, about half of them came from Connecticut.

Good news! We confirmed 350 New England cottontail samples in over 35 locations, including three new towns: Haddam, Harwinton, and New Fairfield. Regional monitoring will begin again soon for the 2017-2018 field season.

Live Trapping Cottontails

Because certain New England cottontail populations are healthy and stable in Connecticut, biologists and field technicians can trap individual rabbits and send them to the captive breeding programs underway at the Roger Williams Zoo in Rhode Island and Queens Zoo in New York.

cottontail rabbit

Radio-collared eastern cottontail./Molly Tassmer

To prevent inbreeding, the zoos bring in new rabbits every year, and “founders,” or rabbits that have contributed to the captive population, are “sent home” to be released near where they were originally captured.

Field technicians set traps in dense thickets in areas where there are known New England cottontail populations. To avoid depleting those populations, they trap at several locations rather than removing too many rabbits from a given site.

Trapped rabbits are visually confirmed as New England cottontails in the field, and a tissue sample is taken for DNA testing later on to back up those identifications. The rabbits are weighed and measured. Eastern cottontails and any probable New England cottontails that are not needed by the zoos are given ear tags and released.

New Habitat on the Way!

As fall progresses, we'll be managing habitat at several wildlife management areas within our New England cottontail Focus Areas. Habitat improvements are underway on a 27.7-acre plot at Assekonk Swamp WMA and a 33.3-acre plot at Pease Brook WMA.

Wildlife biologists and foresters have also completed plans for creating young forest habitat on Aldo Leopold and Mad River WMAs, with work scheduled for later this fall and into the winter.

Both WMAs have known New England cottontail populations. Areas where cottontails currently live will be buffered from the new habitat work to protect cottontails residing there. Once it grows in, the fresh habitat will give those populations area into which individual rabbits can disperse, letting the populations expand.