Field Journal 3: Ecological Physiology

Date - 3/6/21
Start time - 9:10 am
End time - 10:37 am
Location - UVM Campus, East Ave, and Centennial Woods
Weather (temperature, wind speed/direction, precipitation) - mostly cloudy, 18 degrees F, 9 mph NW wind
Habitat(s) - started out in residential area along a relatively busy road, moved into wooded area, mostly pine stands with some deciduous trees.
Although spring is slowly getting closer, it's still pretty cold and there is snow on the ground. Winter isn't over yet. One thing that was obvious to me as we were walking through the neighborhoods and into the woods was that birds have very very few choices when it comes to food resources. The ground is frozen solid still and is covered in snow, so there's no way to get to worms or insects in the ground. There are some soft fruits on trees, like crabapples, but these are few and far between. My guess is that most of the insectivores and frugivores are farther south for the winter and what's left are the birds that feed on nuts and seeds, especially pinecones, and carnivores, like owls and raptors. Many of the birds that we saw feeding were around spruce and pine trees, suggesting the importance of cones for winter bird survival.
One of the biggest struggles for birds that stay up north for the winter is probably keeping warm and finding shelter. The best places for this cavities in old snags in the woods. Most of these are created by woodpeckers and are used by chickadees and other cavity nesters to protect themselves from the wind. Also, in order to be more efficient, I would guess that most birds spend their energy on feeding as much as they can to generate more heat and keep warm.
It seems that most of the snags with large number of cavities in them are older snags that have had lots of time to really break down. The more decomposed trees with thinner bark are probably easier for woodpeckers to drill in to and have more room inside for nesting. I think birds like swallows and nuthatches, specifically, take advantage of cavities because of their small size and their ability to squeeze in and protect themselves.

Publicado el 08 de marzo de 2021 a las 09:22 PM por