Field Observation 3: Social Behavior and Phenology

On March 22nd, I arrived to one of my classes early and noticed several Cedar Waxwings and American Robins eating red berries off of a few trees just out the window. They mostly ignored each other, though the robins from time to time would chase off the smaller waxwings. Within the individual species, multiple waxwings would sometimes feed from the same branch, and robins were more likely to sit near other robins. The waxwings would also frequently hang upside down or at an odd angle from smaller branches in order to reach berries. There was minimal conflict between individuals of the same species, likely because the berries were relativley plentiful and breeding season is still a few weeks off at least for both species. Most conflict was resolved quickly, with the "aggressor" simply landing very close to a smaller bird and causing the smaller bird to fall off or fly away.

In terms of plummage, both male and female American Robins had their signature red breast. While not as bright as say a Northern Cardinal, it is distinct and unique, and likely used for intraspecific species recognition. Females and immature individuals may be slightly paler, though the contrast is often relativley minor. From my vantage point I wasn't really able to differentiate. Cedar Waxwings likewise have minimal sexual dimorphism, and all the ones I saw had adult plumage. They're easily recognizable by their black eyes and small crest.

Later that evening I came across a group of American Crows roosting together in a tree. There was minimal calling and some individuals came and left but of the lone crows I spotted most of them did touch down in the tree. This leads me to believe that this tree is regularly used or that grouping is determined by one individual seeing where others have already begun to congregate. One in the tree interaction between individuals was minimal.

Mini activity: I didn't manage to find any groups of chickadees, but on the 21st I took a ride on the bike path stopping occasionally to explore wooded areas and look for birds. I heard several chickadees but was only able to spot a few individuals. Of those individuals, one did seem to come a bit closer in response to my "pshh"-ing, though I think it may have just been passing by me on its way to get somewhere else. The sound had no effect on the others.

Posted on March 27, 2018 01:23 AM by