Field Journal Entry #2

Date: February 23, 2024
Start time: 15:54
End time: 17:03
Location: Centennial Woods Natural Area (44.475362, -73.188345)

Temperature: 46°F
Wind speed/direction: 10 mph SSW
Precipitation: 0”
Habitat(s): mature conifer stands, mixed hardwoods, fields, streams and wetlands

Species List:
Black-capped chickadee (Poecile atricapillus)
Dark-eyed junco (Junco hyemalis)

Today’s fieldwork took place at Centennial Woods Natural Area to observe some of the strategies resident birds use to survive the harsh Vermont winters. The first species I encountered was a group of Black-capped chickadees (Poecile atricapillus) at the entrance as well as two Dark-eyed juncos (Junco hyemalis). This did not surprise me because chickadees and juncos are both typically found in groups and prefer edges of forests. As I observed their behavior, I noticed that they were foraging in a shrub of some sort. Upon closer inspection of the shrub, it seemed to be some sort of juvenile ash intertwined with a species of Rubus. It would make sense that the chickadees were hanging around here because these two species of trees are important food sources for wintering birds as they provide seeds, berries (if there are any left), and shelter for small birds such as chickadees and juncos. They also may be eating the buds off of these trees. In the winter, these birds must not be getting much protein because the insects that usually reside in the bark of ash trees have all died by now. This shrub also provided the birds shelter both from predators and the harsh winter winds.
Not much further into the woods, I stumbled upon a snag with many cavities. This must be like a condo or an apartment to birds because there were so many places to choose to spend overnight. The cavities were relatively small, the perfect size for a junco or chickadee, so I think it is safe to say this is where these birds may be storing food or sleeping overnight. Snags are essential to resident bird survival in Vermont winters. Black-capped chickadees have a unique strategy to conserve energy and body heat during winter called facultative hypothermia which, in the simplest terms, is hypothermia on purpose. These birds are able to lower their metabolism to the point of hypothermia in order to survive on very low energy reserves. If their metabolism gets low enough, they enter what is called torpor. Torpor is the most extreme form of facultative hypothermia and leaves the birds very vulnerable to predators because they are unable to rouse or function normally. This is why snags are so important to resident birds in winter because it allows them to conserve energy in a safe place from predators.

Publicado el febrero 26, 2024 07:04 TARDE por noxgiordano