Monday, December 7, 2020

On the trail of the elusive cottontail

 By Beth Sullivan

While most people are thinking of reindeer at this time of year, some of us remain focused on rabbits. New England Cottontails to be exact.

A bit of history:  There are two cottontails in CT.   The native one is the New England Cottontail (NEC). The more abundant, and frequently seen, Eastern Cottontail (EC) was introduced many years ago as a game animal.  The EC was more competitive and adapted to fragmented fields, forest edges and neighborhoods while the NEC is at home in dense growth, thickets and briar patches.   It is impossible for any but the very best experts to try and identify them in the field. They appear identical, but they are distinct species and do not interbreed.   Over decades the NEC population declined steeply, partly due to the competition but also due to loss of habitat. As old farm fields were abandoned, there was a period when the thicket and young growth was perfect for NEC, but now, those lots have grown into mature forests, with little ground cover, and many areas are fragmented by neighborhoods and development, suitable for EC. 

Three vials of pellets, labeled and ready to be processed. Photograph by Andrea Petrullo.


Young forest habitat

The young forest habitat, as it is called, or early successional forest, has become scarce. And with habitat decline, a large number of other species associated with that habitat declined as well. While biologists were noticing the NEC decline, they also noted loss of grouse, woodcock, blue-winged warblers, rufous sided towhees, as well as certain reptiles, amphibians and insects all part of that ecological niche.  Over fifty species dependent on that dense, young thicket growth were imperiled. Numerous organizations, including DEEP, US Fish and Wildlife Service, and National Fish and Wildlife Federation, partnered with land-owners, public and private, including Avalonia, to create suitable habitat.

In 2013 The Peck and Callahan preserves were managed for this purpose by cutting older growth and opening up the land for new.  You can read older posts about this project here , here , and here . The biologists believed that if we gave the nearby population of NECs a welcome mat, they would find the area and colonize it. This occurs frequently along powerline corridors where animals can move safely from one place to another in safe shrub cover.   Over the last several years we monitored the site. We photographed the growth of plant life, noted the return of numerous different bird species, abundant insects and saw signs of other wildlife using the area. Neighbors reported larger mammals using the area, such as bobcats and coyotes, but how could we tell if we had any New England Cottontails?

 In 2012 there was no place for a rabbit to hide and we could walk through easily.

 The first growing season offered little cover, except the large brush piles.

By 2018 the same area was lush habitat.

Now the area is thick and dense with young trees and shrubs even in winter, except where Eversource continues to cut.

 We marked this as a photo point. The first year there was nothing growing. Now the stems are numerous.


In search of bunny poop

Well, it’s interesting and an adventure not everyone would appreciate. The only way you can definitively identify NEC is by DNA, and that DNA is found in their pellets. Yes, whatever you choose to call it: pellets, scat, feces, it is bunny poop!   And to find it you have to hunt for it. It is a lot easier when there is snow on the ground making them easier to see.   Sometimes you just have to take an opportunity when it arises. About a week ago, I was contacted by Andrea Petrullo, a contractor to the DEEP Wildlife division through the Wildlife Management Institute. She is the New England Cottontail project’s lead technician.   We had to go on a Sunday to avoid the hunting in the area, and there was no snow on the ground; everything was shades of brown.   We donned heavy duty briar proof and moisture proof bib overalls ( so lovely) over our warm clothes, boots and gloves and armed with clippers, cell phones, and lots of paperwork for Andrea, we headed deep into the preserve. It was not easy. We had to push our way through some of the densest vegetation I have ever had to deal with, and much of it was covered with sharp thorns.  But when searching for signs of rabbits, you have to think like one. We got down low, followed small paths in the underbrush and noted nibbled plants and woody stems. A rabbit nips a stem with a very sharp bite, at a 45-degree angle, which is very different from how deer eat, leaving a ragged, torn flat top, often higher up from the ground.  And when bunnies eat, their pellets can’t be too far away.  As Andrea and I combed back and forth through the brush, we had conversations about topics only other naturalists/biologists would appreciate, such as the finer distinctions between fresh and older excretions-color, distribution etc.  We did have fun and after about 3 ½ hours, we had discovered at least 12 distinctly different locations to collect specimens. They were collected into special vials, marked and labeled, as well as identified by GPS location.

When we emerged, we were beat up, jackets torn and hands scratched up, but we were enthusiastic that we had so many specimens.  While it is possible that there could be regular Eastern Cottontails in there, the habitat is not to their liking, and it is much favored by New England Cottontails. Andrea took the specimens, and will keep them frozen. The DNA tests won’t be run until next summer, as it is an involved process and they do many samples at the same time.  The young forest looks bleak at this time of year; all woodlands do. But if you know how and where to look, you can be rewarded with findings only a biologist could appreciate.  

Look closely and you can see the stems are nipped with a very sharp bite at a 45-degree angle. Rabbits for sure.

With protective clothing, Andrea could get deep into the briars.


Photographs by Beth Sullivan, unless otherwise indicated.

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