Hawk Watching for Science

View to the northwest from the observation tower at the summit

Jim Armbruster- Research Coordinator

Watching migrating hawks is a yearly fall ritual that can include observing thousands of Broad-wings fly over a site in a single day. Watches like Putney and Pack Monadnock see these numbers every fall in mid-September during ideal weather conditions which include the days following the passage of a low pressure system and winds from the north. Though we did not see these numbers at Ascutney, we were able to observe several kettles of Broad-wings fly past the site. Our big day include almost 50 hawks.

Sign near one of the watch locations

These were not entirely unexpected results. Broad-winged hawks are known to follow flight paths that experience favorable winds. Putney is located along a ridge line that helps with the development of thermals and funnels birds past their watch. Ascutney is a large obstacle that most birds fly around rather than over. A majority of birds observed at our site would be following the ridgeline around the mountain rather than over our site. Thermals would develop later in the day which led to the gathering of several birds in an area that would fly up and over the ridge. Species observed included Sharp-shinned Hawks, Broad-winged Hawks, Red-tailed Hawks, Peregrine Falcons, and Bald Eagles.

Haze from the California wild fires was observed at the watch site

Part of our mission for the first season had been to determine where migrating birds would be moving in relation to the mountain. We were using the sheer size of the mountain to see birds moving in all directions. With this knowledge we can better focus our efforts in coming years to count the number of migrants past the site. Despite the lack of migrating birds there were definitely some exciting moments including a resident family of Peregrine Falcons dive bombing the local ravens and the passage of three migrating juvenile Bald Eagles directly over the site. The “office views” were also something to be appreciated during the season.

Fall foliage from the west summit
Two juvenile Bald Eagles

Hawk watches are important to help groups like the Hawk Migration Association of North America study the migration patterns of raptors throughout the country. Having a site in Ascutney provides one more look at the migration through Vermont and provides valuable data for future studies.

Hawk Watch at Mt. Ascutney

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