ID Flight and Physiology

Date - 2/21/2021
Start Time - 9:09am
End Time - 10:40am
Location - UVM Redstone Campus, South Prospect Street
Temperature - 23 degrees F
Wind Direction - N/NW direction
100% sun

We saw a handful of Herring Gulls (I myself saw around 4) and potentially some Ring-billed Gulls circling around the area between the Interfaith Center and Redstone Hall, having apparently caught a thermal and gliding in a circle up above. The Herring Gulls had black streaking on their head in line with their prebasic molt taking place, and they had distinct long, high aspect ratio wing-types. As they glided in a circle above us, they flapped their wings only ever so often, spending most of the time just gliding in a fairly relaxed manner. Their high aspect ratio wings clearly are giving them a lot of lift and making it so that they didn’t need to use up a lot of energy. It was a little surprising to find them a little ways away from Lake Champlain, especially on the walking path leading to Redstone, but it made sense given their long wing length, which would result in a lot of lift and take the Herring Gulls easily to and from place-to-place with little effort. Even if their habitat niche is around bodies of water, their wing-type makes travelling long-distances very simple for them.
This is in contrast to both the American Crow and the American Robin species that we saw, which both seemed to have some cross between an elliptical and high-speed wing-type. The American Crow definitely erred more on the side of an elliptical wing-type with its splayed, broad feather tips, but through the binoculars I could see it flapping very rapidly and regularly in the vein of a high-speed wing-type. As Allan said, crows are generalists! They fly in both open areas and through forests, making their broad-tipped elliptical wings helpful for a variety of terrains. And they also fly long-distances to get to these areas, making the more sharp relief of their wings less long and apt for gliding and more dynamic for high-speed travel. American Robins also flapped very rapidly to and from their various perches on the Redstone Green, rarely ever gliding. I would hazard a guess that they are also generalists, getting food from multiple areas both open and forested just like the American Crow.
Maybe I’m a bit of a novice, but we saw a lot more birds than I thought we would in the cold. We saw a lot on the Redstone Green where there was a crabapple tree feeding around 8-9 American Robins, and easily around 30+ birds in a residential road just off of South Prospect Street where there were multiple bird feeders. The majority of species we saw in the residential area were Common Redpolls, though there were ~5 Mourning Doves and at least 1 male White-breasted Nuthatch. We found a lot of the birds perched on various buildings around the Redstone Green, probably trying to get some of the sunlight that was shining down on us, and also because it was probably near some of their nesting areas (like the two Rock Pigeons we found tucked into a corner of Redstone Hall)! I think there’s definitely the perception (at least that I had) that there are barely any birds in the winter because they migrate, but obviously many birds stick around during the winter months without any problem, likely adapting to the change in season by molting into their winter plumage (like the Herring Gulls’ black streaking on their heads). We found the most birds where there were areas of food, and where there was a tall building or tree to perch on.

Julkaistu helmikuu 22, 2021 01:04 AP. käyttäjältä