Saturday, January 16, 2016

New England Cottontail Rabbits

Note: This program first aired on January 16, 2016.


Join me in a thought exercise for a moment. Think of the most beautiful landscape you can imagine, one worthy of protection in perpetuity, one that meets all of our emotional, physical and spiritual needs. You may have conjured up an image of a mountain with a waterfall, a babbling brook, an open forest. Maybe a woodland or grassy savannah with a view from a high point. There are endless possibilities. One image I can almost guarantee you did not picture is a low shrub thicket tangled with thorny brambles and vines, with 20,000 to 50,000 stems per acre, virtually impossible for a human to walk through. But if you were a New England Cottontail Rabbit, this is exactly the landscape you would be imagining.

New England Cottontails are Maine’s only true rabbit, and Maine’s only state listed Endangered terrestrial mammal (the Snowshoe hares who’s tracks we see everywhere in the winter are different). Historically these rabbits lived throughout New England from just west of Penobscot Bay all they way to the Hudson River, down to Long Island. New England Cottontails became an Endangered species in Maine (and qualify for various levels of protection in the rest of New England) for one big reason, habitat loss. Since 1960 habitat for New England Cottontails has declined over 80% across its range. All animals are dependent on the environment to provide for their physical needs, habitat provides shelter from the elements, protection from predators and a supply of food. New England Cottontails are specialists when it comes to habitat requirements, they are adapted to be need very specific attributes in the places they call home. And those attributes include dense vegetative cover composed primarily of woody shrubs and small deciduous trees 3 to 15 feet tall, in patches of 10 to 25 acres. Size and structure.

The problem is that we don’t have very many stable shrublands here in New England, meaning, shrubs generally aren’t a climax vegetative community. These thickets primarily form as a result of landscape disturbance, they are what is called in ecological terms “early successional”. After a forest clearing disturbance the first plants to come in and colonize the disturbed area tend to make a dense thicket of herbaceous material, shrubs and sapling trees. This community only lasts 20 years at most before the tree saplings grow tall enough to shade out the understory, which opens up the thicket and degrades the habitat for the New England Cottontails. Which means, in essence, New England Cottontail rabbits are a disturbance dependent species.

The reason that they are now in decline is that we humans don’t like disturbance very much, nor do we appreciate landscapes that change over time. New England Cottontail rabbits got a temporary boost when agriculture declined in Maine, and thousands of acres of fields transitioned from open hay or cultivation back to forest. Initially the regrowing fields provided perfect thicket habitat, but then ecological succession continued, and the thickets were replaced by young forest. Additionally, we actively suppress fires, cut dead wood and otherwise manage forests to minimize disturbance and maximize the development of multi age climax forest stands. Essentially we do everything we can to prevent the kind of disturbance that will create new habitat for the New England Cottontail; we fanatically mow to keep open land open, and actively encourage the development of forests, dismissing all the messy swampy shrubby stuff that comes inbetween. We are effectively holding the landscape static, when static is exactly what natural landscapes are not. In doing so, we have a significant negative impact on organisms that are dependent on this ephemeral natural community; the New England Cottontail may be the most charismatic of the bunch, but over 100 other species of special concern share the same habitat requirements, suffer the same declines at the loss of habitat, and enjoy the same benefits of active habitat restoration.

Restorative action is taking place in all of the 5 remnant populations remaining in the rabbits’ historic range. Landowners are working with state and federal officials, doing things that seemed unimaginable to the conservation minded citizen years ago, clear cutting small tracts of forest, mimicking the natural small scale disturbance caused by low intensity fires, beaver flooding and wind storms, allowing patches of early successional habitat to flourish. This is truly “next level” conservation, working with natural patterns over both time and space to create a dynamic long range management plan that honors all species, not just the climax community ones. Sometimes it just takes a cute little bunny to get us there.

From US Fish and Wildlife Service



References: 

Federal US Fish and Wildlife http://www.fws.gov/northeast/newenglandcottontail/pdf/NEcottontail2015.pdf  

Learn everything you wanted to know about New England Cottontail Rabbits: http://newenglandcottontail.org/

Maine Dept. of Inland Fisheries and Wildlife: http://www.maine.gov/ifw/wildlife/species/mammals/endangered.html