Birding at Ethan Allen Homestead

Ethan Allen Homestead
Sunday 03/07/2021
10am to 11:30am
Floodplain Habitat. Large open agricultural fields interspersed with sparse riparian woodland. Common tree species include silver maple, eastern cottonwood, American elm and boxelder.
Sunny with some clouds. 20 degrees Fahrenheit. 5mph winds from the north.

One way I noticed birds adapting to winter was through their activity. I watched one Black-capped Chickadee in constant motion for about five minutes. It flitted back and forth from a bush to a picnic bench with some food scraps on it, either moving or eating. Once it finished this routine the Black-capped Chickadee stayed in the bush and fluffed itself up. It looked much larger than it did when it was active. It stayed like that until I moved on. Birds like the Black-capped Chickadee, which stay in Vermont all winter, must spend more of their time resting and staying warm than being active. Based on this one observation, when they are active, they are moving constantly trying to stay warm while looking for food or eating.

Another way that birds adapt to winter is through their nesting habits. The Black-capped Chickadee, Tufted Titmouse, Barred Owl and many other birds that stay in Vermont all winter long are cavity nesters. The cavity provides a sheltered area where they can stay warm during cold winter nights. The snag provides insulation and some wind protection. I wonder if some of these cavity nesters huddle in larger cavities together to stay warm through each others body heat. I also wonder if these birds have a way of slowing down metabolic processes in order to conserve energy. During winter, much more time must be spent in the nest, mating, incubating eggs and taking care of young.

Cavities are most often created in snags. This makes snags an important part of a forest ecosystem as it provides habitat for the aforementioned cavity nesters. Some other species of cavity nesters include the White-breasted Nuthatch, Hairy Woodpecker, Downy Woodpecker and Common Goldeneye. These species stay in Vermont all winter long and need the cavities to stay warm in the winter. I noticed that larger trees will often have a greater percentage of their area covered by cavities. On the other hand, it seemed that every smaller snag (under ten feet tall) I passed only had one or two cavities in it. I thought this might be because larger snags have a greater diameter and are able to have cavities on either side of it without the cavities reaching the middle and causing the tree to fall down. As snags get a larger diameter their importance to bird habitat must also increase.

I think older forests that are more dense might have more standing snags and thus provide better habitat for cavity nesters. I saw several snags that were being supported by live trees. A denser forest might have more standing snags because the chances of that snag being caught by another tree as it falls would be much higher. A denser forest might also have a root network that is more tightly interwoven, holding onto the dead trees for much longer than a loose root network.

Posted on March 8, 2021 02:32 PM by samharesteig