About the Survey

From 2002 to 2007 volunteer butterfly enthusiasts spent thousands of hours in the field in an effort to record the status and distribution of Vermont butterflies, the first systematic statewide butterfly atlas to be undertaken.


The data was collected within a grid based on USGS topographic quadrangles. Each quad was divided into six equal blocks for a total of 1,104 blocks. Each block was approximately three square miles. One block from each quad was randomly selected as the priority block for a total of 184 priority blocks. There was no statistical difference in the percent coverage of priority blocks within each biophysical region (see table below).

Participants attempted to verify the presence of as many species of butterfly as possible within each block, noting a variety of other data with each record. The result is the most detailed database of the spatial and seasonal distribution of Vermont butterflies ever compiled.

This survey represent a “snapshot” in time of Vermont butterfly distribution. This is the primary function of a biological atlas for conservation purposes—to set a baseline against which successive future surveys can be compared. Butterfly population, like other organisms, are not static but change in status as a result of land use change, adapting to new food plants, climate change, and other factors. With that in mind, we look forward to the 2nd Vermont Butterfly Survey 20 years from now.


Biophysical Region

Percent Covered By Priority Blocks

Northeast Highlands 18.9
N. Piedmont 16.6
N. Green Mountains 21.7
Champlain Valley 18.2
S. Piedmont 20.4
Vermont Valley 19.4
S. Green Mountains 19.8
Taconic Mountains 17.2
State of Vermont 16.7