When I bring up the topic of North America’s fall bird migration most people think of the awe inspiring movement of birds that summer here in the Green Mountains to their distant wintering grounds in South America. It’s the compelling subject matter that Discovery Channel specials are made about. However, few people think of Vermont as a place for birds to migrate for the winter season.
It is true, many bird species migrate from points north, often above the Arctic circle, to winter here in Vermont. In fact, many species of birds call our wintery portion of the continent a balmy repose in comparison to their breeding grounds of the far north. Each year I look forward to their arrival, and am often surprised by what, when, and where things shows up in Vermont as the far north becomes uninhabitable to these animals.
There are a couple major factors that drive this migration into Vermont. The first, and perhaps most obvious, is the weather. When the weather turns bad there are certain populations of birds that move out. They are hard wired to do so. These are the species we typically see each and every winter.
An example would be the Snow Bunting that lives and breeds on the tundra during the long arctic summer days and winters in the open and fallow fields of the northern United States and southern Canadian provinces. Each year we see flocks of these beautifully contrasting white, black, and – in the case of the females and juveniles - brown birds, move into the neighborhood for the winter. You can often see them flying in unison over the fields. They are very hardy birds that choose to while away the winter here in Vermont.
An additional example is the little Kinglet family (ruby crowned and golden crowned) who breed in the spruce and fir stands of the boreal forest to the north, in addition to the higher elevations here in the Green Mountains. They migrate out of the mountains and into the valleys. Our lower forests are full of them right now. The same is true of the Dark-eyed Junco who is around in sparse numbers until the weather changes for the worse. Then they are found in great quantities in the valleys.
The second major factor that pushes birds out of the north to winter here in Vermont is the availability of food. The bird species that take up residence in our northern forests infrequently stay once every few years and are said to be irruptive populations. Their movement south is driven by a general lack of food on their normal wintering grounds. This pushes segments of the population south in search of sustenance. Species like the Snowy Owl, Pine Siskin, and Common Redpoll all display these irregular, irruptive population explosions here in the Green Mountains. We don’t see them every year, but they do surprise us every so often.
I think that is what I find so interesting about birding in the post -fall migration doldrums. Sure the number and diversity of birds on my daily checklist are a shadow of those taken in May and June. However, during our “stick season,” you never know who will show up for the binoculars. It keeps me looking at the ubiquitous, albeit entertaining, groups of Black-capped Chickadee to see who else may be hanging about - this is especially true of the Kinglets whose antics with the bands of Chickadees brighten any gray cold day.
Adding in the other year round residents like the Wood Peckers, Owls, Nuthatches, the Brant Waterfowl on open water, Goldfinches, and the like make for a compelling morning birding in the woods.
Our November woods are very much alive, despite their appearance. Sure many birds have left for the warmer climates of the Gulf of Mexico and in many cases South and Central America, but many have also showed up in the lower elevations from as far away as the Arctic to spend their winter in, the relatively speaking, balmy Vermont.