Some of the year-round species I saw were White-breasted Nuthatches, Black-capped Chickadees, and Tufted Titmice. They may forego migration because they do not have the energy needed to migrate warmer areas. Because they don’t migrate, they need some adaptations to get through the winter. For example, Black-capped Chickadees go into facultative hypothermia to save energy. This is a physiological adaptation. A behavioral adaptation that may birds have is they can puff up their feathers to trap heat.
I didn’t know what the difference between facultative and obligate migration, so I looked that up first. I now understand that facultative migration is optional and usually happens in response to the environment while obligate migration is “hard-wired” and usually happens at the same time each year.
Considering a facultative migrant, the species may be coming from the south where it is warmer and there may be more food and other resources available to help them survive the winter. I did not see ant obligate migrants. Some advantages of arriving in Burlington this early may be getting first pick at breeding habitat and first pick at food resources. Some disadvantages of arriving in Burlington this early may be that the weather is unpredictable here during this time of the year. While it is starting to warm up, we still may get some pretty intense cold snaps that could be harmful to these species of birds.
For the mini activity, I saw a lot of American Robins. American Robins are considered facultative migrants. According to All About Birds, the American Robin breeding range is in Canada and the northern most parts of the US and their winter range is in northern Mexico and the southern most parts of the US. They begin migrating south when temperatures being to drop, usually in October. They migrate back north beginning in early spring. According to Columbia University, American Robins can fly up to 250 miles a day during their migration. Their migration distances may vary, but I calculated that from the Ethan Allen Park (where I saw them) to the closest part of their winter range, in northern Florida, an American Robin may migrate 1,103 miles.

Posted on March 27, 2023 08:11 PM by ajberkow