Field Journal 7: Reproductive Ecology and Evolution

Date: April 26, 2021
Start: 12:15 pm
End: 1:45 pm

Location: Centennial Woods
Weather: Chilly (~35℉), overcast and windy
Habitat(s): dense forest, nearby stream, on incline

I decided to observe bird activity along the Centennial Woods nature path. The habitat is made up of both deciduous and coniferous trees and declines in elevation as you get further from the roadside entrance. I passed a few clearings made up of grass and brush as well as some marshy areas once you get to the bottom of the hill. At this point, it’s rather flat with a nearby stream and a field of reeds/cattails. It was a bit cold during my trip and I believe this to be the reason why bird activity was pretty low. I saw only six different species and only a few individuals of each kind.

I heard quite a bit of birdsong along my walk. In particular, I recall hearing two distinct chickadee “hey sweetie”s repeatedly calling to each other. I could tell they were different birds because one song was higher pitched than the other. I assume this to be two males either competing for a mating or defending their own territories through use of song. This took place a bit off the path while I was sitting beneath a large evergreen tree. Based on the apparent competition and dense vegetation of the area, the spot seemed to be prime territory. Other factors that led to my conclusion is the distance from human interaction (the path) and nearby access to the stream. The fitness of these two birds, because of the quality of the territory and eagerness of both birds to defend it, is probably high.

During my trek, I noticed multiple different nests. One was found in a smaller tree with pinecones. It was small, about 5 inches in diameter, and made out of tightly woven twigs and grass, likely belonging to a small songbird species such as a chickadee. Another nest I saw was high up in a tree and looked much larger, maybe about 10 inches in diameter. My view of it was from quite a distance, but I believe it was crafted from larger twigs and leaves and possibly down feathers (this is based off the fact that I noticed a lot of down feathers on the ground). Because of the height and proximity to the trunk of the tree, I think this could have been a crow’s nest. I also spotted a crow flying overhead not too far away at the end of my walk.

Posted on April 26, 2021 08:05 PM by