Migration

Date: 4/7/18
Time: 4:15-6:46pm
Location: Salmon Hole
Weather: Partly cloudy, 40°F

The first birds I saw on the Winooski River were a pair of Mallards feeding on the main section of the river. I learned from All About Birds that Mallards are not residents of Burlington. However, their early arrival means they are the first to find nesting spots, food, and mates. Disadvantages to being the first to arrive include the risk of facing resources not being available yet and inhospitable weather.

The majority of the Mallards were probably coming from the south, and some possibly from the northwest, where they winter. I’m assuming the main factor prompting their migration to Burlington was the hours of light in a day where they came from. Since Mallards also migrate in flocks, social behavior was probably the second most influential factor.

I also saw a pair of Hooded Mergansers in the floodplains of the Winooski River. Hooded Mergansers are year-round residents in Burlington. Benefits of staying year-round include the ability to defend territory at all times and save energy that would’ve been used traveling. Hooded Mergansers also begin mating in March, which would not be possible if they were migrants.

Adaptations like the Hooded Merganser’s widely varied diet, compared to closely related species like the Common Merganser who migrate, can help to ensure the Hooded Merganser has sufficient food throughout northern winters. Hooded Mergansers also take advantage of tree cavities to nest in so they are protected from harsh weather.

Other than the Mallards and the Hooded Merganser, I saw an American Robin eating wild grapes alone on an abandoned brick wall and a pair of Canada Geese. This means that the Mallards were the only migrants I saw during my time of observation. If the pair of Mallards migrated to Burlington from the south, they have flown at least 95 miles. Together, that’s >190 between just a couple of ducks.

Publicado el abril 9, 2018 03:41 MAÑANA por fnovella