Field Observation #2

Earlier this morning (March 7th, 2016), I ventured out to Arms Forest behind Burlington High School. When I arrived, it was chilly and quite windy; for the first half hour, I had minimal luck spotting any birds. Calls were distorted by the wind, and it seemed like there were more sounds from tree branches rubbing together than from birds. Moreover, the overcast sky made everything look washed out - I'm not sure I would've been able to definitively ID many birds in those conditions anyway!
Thankfully, I did eventually hear some American Crows, Black-Capped Chickadees, and Northern Cardinals. After about an hour of minimal observations, I began to wander back toward the parking lot. As I was entering an area beneath a canopy clearing, I looked up and saw what I believe was a Cooper's Hawk. I identified it by its broad wings, its size, its long, almost rectangular tail, and its brown and white plumage. Unfortunately I couldn't get a picture, but I did some digging through my field guide and believe I've ID'ed it correctly. After seeing the hawk, I decided that I should wander down to North Beach (the direction s/he had come from).
The beach was incredibly windy, which, while not surprising, made me worry that I wouldn't have any luck with sightings. However, almost immediately I saw three Herring Gulls enjoying the icy breeze. There was also a crow settled in a tree. On my way back from the beach, just as I was about to cross under the bridge, I saw one of the highlights of this excursion: a group of American Robins foraging on Rhus typhina flowers. There were at least a dozen of them, all pulling at the densely clustered seeds of the staghorn sumac. These flowers probably make excellent winter forage because they are so persistent and abundant along edges.
Eating these foods is a behavioral adaptation that allows winter survival. I also witnessed a crow fluffing up its feathers to help insulate it from the cold. The habit of nesting in protected cavities in snags can also help birds remain at safe body temperatures. I counted eleven snags on my path, but only found one of them to be occupied (through the rap test). Unfortunately, it was not occupied by a bird - instead, I found a domestic cat! It was a fun reminder of the myriad of unexpected ways that organisms can overlap in their interactions with the world around them.
Many of the snags I saw had clear evidence of woodpeckers. Particularly large snags tended to have larger cavities that looked like the result of a Pileated Woodpecker's work. There didn't, however, appear to be any strong correlation between snag abundance and bird abundance at this particular time.

Posted on March 7, 2017 07:00 PM by cafrigo