Field Journal 5

Today is April 8th. I was outside observing birds from about 12 PM until 2 PM. The weather is relatively warm, in the late 40's. I was again in my backyard in North Andover, Massachusetts, this time with a bird feeder set up. One of the species I observed was the American Robin (which I believe is a facultative migrant species). They may forego migration because of territorial reasons. They don't want others in their territory, and it also gives them early access to the best breeding grounds. To adapt to staying in the winter, Robins change their diet from insects to winter fruits since insects are scarce in the freezing temperatures. They also form flocks so that it is easier to avoid predators and have a better chance at finding food. Another facultative migrant that may be arriving in Burlington would be the Red-winged Blackbird. It was probably coming from the southern United States traveling either to places like Vermont or Canada for the warmer weather. The weather down south might get too hot for these migrants and decide to come up north where the weather is a bearable temperature in the summer months for them and have easy access to food. An advantage of arriving in April for obligate migrants might be access to good breeding grounds. A disadvantage might be that there is a possibility of cold weather still happening and less food availability. Also, more susceptibility to predators in Burlington.

Posted on 08 de abril de 2020, 05:59 PM by juliannamason