The Natural Heritage of Cady Hill Forest
This article is an excerpt from the Winter 2012 issue of Mountain Views.
This fall, as we walked through the woods in our brightest orange hats and vests, we were thinking about the role of White-tailed deer Odocoileus virginianus in the northern forest ecosystem in which we live.
White-tailed deer in Vermont live near the northern limit of their range in eastern North America. To cope with Vermont's severe climatic conditions, deer have developed a survival mechanism that relies on the use, access, and availability of winter habitat. These habitat areas are known as deer wintering areas, deer winter habitat or, more commonly, 'deer yards.' Deer winter habitat is defined as areas of mature or maturing softwood cover, with aspects tending toward the south, southeast, southwest, or even westerly and easterly facing slopes.
Just over 100 acres of Cady Hill Forest has been designated by the State of Vermont as deer wintering area. The easement that Stowe Land Trust (SLT) will ultimately hold on the land will provide protections for deer and their habitat. It will be up to the State’s Act 250 process to determine exactly what the protections will be, but it is certain that parts of the property shouldn’t be disturbed by human activities in winter.
Deer wintering areas vary in size from a few acres to over a hundred acres and provide essential relief to deer from winter conditions. These areas of softwood cover provide protection from deep snow, cold temperatures, and wind. They provide a dense canopy of softwood trees, a favorable slope and aspect (mentioned above), generally moderate elevation, and low levels of human disturbance in winter. The softwood species that compose these areas are most commonly hemlock and white pine in the southern part of the state, and white cedar, spruce, and fir in the north.
Energy loss by deer inhabiting these sites is minimized, and survival is favored in deer wintering areas. Wintering areas do not change significantly between years and can be used by generations of deer over many decades if appropriate habitat conditions are maintained. Deer annually migrate, often several miles, from fall habitat to wintering areas. A single wintering area often serves deer from large areas of town and in some cases from surrounding towns as well.
Residential, commercial, or industrial development within or adjacent to a deer wintering area decreases the amount of winter habitat available to deer and has an effect on an area's deer population, eventually reducing the number of deer within the area. Without adequate winter habitat, northern populations of deer would be subject to extreme fluctuations due to heightened levels of winter mortality during moderate and severe winters.
Wildlife managers charged with the tricky task of managing deer herds must weigh biological and cultural considerations in determining target deer density. How many deer per acre would hunters like to see? Probably more than a healthy forested ecosystem can sustain. Deer are native animals, so their consumption of food and survival is part of the natural predator-prey dynamics of the forest system when their population size is appropriate. When deer wintering habitat is eliminated by development, it can have severe repercussions for the herd for generations.
Birds of Deer Wintering Habitat
A key component of deer wintering habitat are the conifer stands with dense canopies that catch the snow on their branches, thereby reducing the snow depth underneath. Deer also need adequate food resources nearby –that means low, woody vegetation.
If you snowshoe through a deer wintering area, you may observe chickadees, a red-breasted nuthatch, golden-crowned kinglets, and maybe even red or white-winged crossbills, as well as deer.
In the summer, the same stand of trees will make excellent breeding habitat for the brilliantly colored blackburnian warbler. They live in similar habitat to black-throated green warblers, but the two closely related species are able to coexist because blackburnian warblers forage and nest high in the canopy of coniferous trees. In fact, they are the only warbler to habitually nest above 12 meters in the coniferous forests of New England.
Habitat Conservation Goals
The VT Department of Fish and Wildlife has developed conservation goals to help landowners enhance State designated deer wintering habitat. They include:
1. Maintain and protect the functional integrity of deer wintering areas within the town or area of interest.
2. Increase the number of deer wintering area acres that are either under long-term stewardship or that are permanently conserved in the town or area of interest.
A management plan is being developed jointly by the Town of Stowe, SLT and the Stowe Mountain Bike Club to help promote healthy habitat in Cady Hill Forest. The Act 250 permitting process may recommend that the management plan include one or more of these goals to promote healthy habitat.
Additional information on the winter habitat requirements of deer can be found in Wildlife Habitat Management for Vermont Woodlands, a Landowner's Guide, which is available from the Vermont Fish and Wildlife Department.
Sources for this article include the VT Fish & Widlife Department and Audubon Vermont.
