April 6th Bird Walk

During my birding adventure for this week I encountered, as I do most days during the spring, a group of Robins hopping around and feeding on the somewhat frozen ground. While some Robins do migrate south for the winter, many individuals choose to stay here and conserve the immense amount of energy it would take to breed. Although the ground freezes during the winter, preventing robins from having access to the earthworms that usually make up their diet, they can switch to a diet of fruits that allows them to have a consistent food source without actually migrating. While overwintering here in Vermont, these birds need to find shelter during periods of cold temperature and high winds. Dense coniferous forests provide birds with significant protection from the elements. Robins also fluff up their breast feathers in an effort to conserve body heat, as well as preening their feathers so that water flows off of them without absorbing into them Robins are able to stand in the snow without their feet getting cold because of the counter-current heat exchange that warms the blood traveling to and from the feet.

During my expedition I also encountered some waterfowl feeding next to and in the Winooski river. Both Canada geese and mallards migrate from their homes here in Vermont down to the southern United States to find food during the winter. Geese primarily eat green vegetation, and mallards eat mostly aquatic vegetation and invertebrates, both of which become unavailable when the grass becomes covered in snow and the water becomes covered with ice. Now that spring has begun, and grass is starting to grow back and the ice is melting and the water is opening up, waterfowl are beginning to come back to Vermont and leave their wintering grounds in the south.

Posted on April 9, 2018 08:10 PM by benupton