Social Behavior and Phenology

Date: 3/13/19
Time: 10:00-11:30AM
Location: Raven Ridge, Huntington, VT
Weather: Warm, around 30 degrees and slightly overcast. Snow is about 20 inches deep in most places.
Habitat: Around the edge of a small neighborhood and a mature forest that was logged last winter.

I observed a couple of Hairy Woodpeckers for about 40 minutes. At first, I could only tag along behind them as they flew from tree to tree. They called frequently, which helped me locate them, but they were always in different trees. One time one of them landed in a tree where the other was, and the other took off immediately, without being pursued. I don't know if they were calling to each other or not, but they were doing the sharp short 'peek' call, not the long rattle/whinny. Finally one of them settled high in a large dead White Pine, where it foraged continuously for at least 15 minutes. It then rested on a branch for about 6 minutes. Overall, during the time I observed it, it spent about 30 minutes foraging, 10 minutes traveling, and 6 minutes resting.

I also observed several species in the area of a few trees at the edge of the yard near a feeder. There were about 5 Black-capped Chickadees, a White-breasted Nuthatch, a Brown Creeper, a Hairy Woodpecker, and a Tufted Titmouse. As far as I could tell, only the chickadees were making use of the feeder – the rest were foraging under bark or calling out territory. The chickadees had a ritual for approaching the feeder: first, they would fly in close to the top of a nearby tree or shrub. Then, they would hop lower down as they scouted out the scene. When they determined it was all right, they went to the feeder, and then returned to their spot in the nearby shrub to eat the seed. Then they would either return to the feeder or go back to the woods. One time, a chickadee tried to land on the feeder while another was already there, and it got chased off with a quick set of chatter and wingbeats.

I tried "pishing" for a while, with various lengths, pitches, and tones to my amateur calls. Felt pretty foolish, and didn't notice any behavioral effect in the nearby songbirds. If pishing does attract small birds, maybe it is because they think there is a small stream nearby that they can take a sip from. Some pishes also sound a bit like an alarm call that is similar across species, so maybe they are coming together to defend an individual against a perceived predator.

The Black-capped Chickadee has black, tan, and white plumage arranged in thick horizontal layers. With dark above and light beneath, it exhibits countershading that helps it blend into its surroundings. Since the little bird forages both high up and on the ground, this makes sense in terms of camouflage. The contrast of black and white on its head likely attracts potential mates. The Hairy Woodpecker is entirely black and white, except for a patch of red on the back of its head, which it can either accent or diminish depending on behavior. It's plumage is arranged in a checkered pattern of regular black and white horizontal stripes across its back. When it clings to a tree trunk or perches on a branch, it maintains an upright body posture, and blends in easily from all sides with the bark and dappled shadows. The red flair on its head can be used in communication, signaling, and courtship. Having a bright splash of color shows evolutionary fitness as it makes an animal more vulnerable to being spotted by predators. Both the Hairy Woodpecker and the Black-capped Chickadee have a pattern of black, white, black on their faces which accentuates their beaks, potentially making them look bigger, stronger, and more threatening.

Posted on March 15, 2019 11:14 PM by zoey_november