March 29th Field Journal

Date: 3/29/23
Start Time: 3:40pm
End Time: 4:40pm
Location: East Woods Natural Area
Weather: 49˚F, 13mph NE winds, 45% humidity
Habitat(s): Wintering old growth forest near busy road

Earlier today I went birding in East Woods Natural Area in South Burlington, VT during the late afternoon. This proved not to be the best location as it was next to a highway and experienced human noise disturbance. The only birds I found were a few Black-capped Chickadees in the distance. This was likely due to the cold temperatures and human proximity. It also seemed to be a popular dog walking area which increased the noise disturbance. A benefit from this was that the dogs shed their fur along the trail, leaving nest building material for the birds in the warmer months.

The Black-capped Chickadee does not migrate for winter because it has characteristics that allow it to survive in cold temperatures. Chickadees go into a state called “regulated hypothermia” where they essentially lower their body temperature and therefore their metabolic expenditure. The bird will consume enough to increase their body weight by at least 10% in order to survive the night. Throughout the night they will shiver to keep warm, thus returning to their normal body weight by morning.

Later on in the New North End I saw a Brown-headed Cowbird calling from the top of a bare tree. These birds are considered shirt migrants, as they migrate only as far as 530 miles between breeding and wintering grounds. They live year-round in the middle and southern US, as well as the top of Mexico. They spend their non-breeding period in southern Mexico and Florida and their breeding season mainly in the Northwest and Canada. Their purpose for migration seems to be for breeding and weather purposes. These birds are starting to return to Burlington because the conditions are once again suitable for them.

הועלה ב-מרץ 30, 2023 03:59 לפנה"צ על ידי lillietyroler lillietyroler

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