Vertebrate Distributions for New England Gap Analysis

Personnel: David Capen, Ernest Buford, Peter Williams

Cooperators: New Hampshire Fish and Game Dept., Vermont Fish and Wildlife Dept.

Using a variety of distributional data, we have constructed range maps of New England's vertebrate species. Sources of data for birds include statewide Breeding Bird Atlas projects and the Breeding Bird Survey. Data sources for mammals and for reptiles and amphibians also include atlas project data, but also rely heavily on data from Natural Heritage programs. An example for willow flycatcher illustrates the process of range map development:

Breeding bird atlas occurences and other sources of data are brought online and consolidated. This flycatcher distribution map shows breeding bird atlas blocks where this bird was found.
Species occurrence records are then used to populate hexagons producing a hexagon-based map of that species range in New England. These hexagons (from the EPA EMAP project) are being used as a standard for National Gap Analysis vertebrate range maps.
The hexagon-based range maps are sent out to be reviewed by qualified experts in each New England state.
Finally, the hexagon maps will be overlayed with habitat maps to produce maps of predicted distribution. Habitat maps are created by using species-habitat associations models to extract appropriate cover types from a land-cover map.

You may notice that our range map for willow flycatcher suffers for lack of a detailed land cover map for the final step (because our land-cover map is still in progress, we used the AVHRR forest cover map for this example).

Recent work on vertebrate distributions also includes production of regional range maps that have been smoothed by bioregions (U.S. Forest Service sections and subsections).

New England Bioregions Black-backed woodpecker range

       Updated: 29 June 2000