Today (8/9) I found a yellow-throated vireo in Belmont, Rutland County, near the intersection of Teer Road and Frost Hill Road. (Belmont is located in the Green Mountains, between Rutland and Ludlow.) The bird was moving with a small mixed flock that included multiple black-capped chickadees, two chestnut-sided warblers, and a red-eyed vireo. My understanding is that yellow-throated vireo is quite uncommon in the Green Mountains, but more common in Vermont in the Champlain and Connecticut River valleys. (I’m visiting from California, and still learning about bird distribution in Vermont, so please correct me if I’m wrong.)
My find this morning got me thinking about birds in the mountains. In the Sierra Nevada mountains (and other mountain ranges in California), there is a general phenomenon of birds that breed at lower elevations moving upslope post-breeding but before southward migration starts for real (i.e. in August). One notable example of this orange-crowned warbler, which breeds at low elevation but can be quite common in meadows high in the mountains in August. Does anything something analogous happen in the Green Mountains? Is there a noticeable push of lower-elevation breeders into the Green Mountains after breeding but before fall migration starts in ernest? Put another way, is my vireo part of a a broader pattern of bird movement?
Thanks for anything that you have to share.
Claremont, CA (temporarily Belmont, VT)