Field Observation: Reproductive Ecology and Evolution

For this week’s birding excursion, I travelled to a local trail system around Turner Reservoir on the border of Seekonk, Massachusetts and East Providence, Rhode Island. I began birding at about three o’clock in the afternoon and I finished around four thirty on Sunday, April 19, 2020. The weather was about 60˚ and quite windy, especially since I was near a body of water. The habitat was different from my previous field observations. The area is heavily forested, consisting mainly of large conifers such as Eastern White Pine and some other deciduous tree species. There is also a good amount of shrubbery and smaller plants on the forest floor. Another unique feature of this habitat is the large reservoir that the trails go around, which provided an opportunity to see both aquatic birds and those species that mainly inhabit forests and woodlands.
I certainly noticed a change in behavior compared to my other field observations, specifically in terms of mating and reproduction. To begin, one of the behaviors I noticed came from two American Crows that I observed. They were acting quite territorial, and by this I mean they were flying from tree to tree, staying in close proximity to one another, all while being extremely vocal. For a while, their call was the only one I could hear. I would confidently say that these birds were defending a territory. The two individuals that I observed specifically seemed to be defending a prime territory, and I say this because I did see at least one other American Crow that flew overhead, but quickly left the area that the other two birds were occupying. On the property, it is likely that the American Crows would nest high up in the trees because that is where I observed the individuals. This may indicate that the bird’s defending their prime territory have high fitness because they successfully remained in place, forcing any other individuals to leave. They were also extremely vocal, which leads me to believe even more that they were defending a territory.
Another species I wanted to focus on in regard to mating behavior was the American Robin. I actually was able to observe two separate pairs of American Robins at different times during my excursion, and each pair exhibited different reproductive behaviors. The first two individuals I saw were simply in close proximity to each other on the ground, likely collecting materials to build a nest, since the forest floor would be a great place for those birds to acquire them. The American Robins, along with other species in this specific habitat, would likely be using pine needles and small twigs to build and line their nests. As I mentioned before, the forest was filled with Eastern White Pines, so the floor was covered in needles, as well as some other leaves and sticks. The other pair of American Robins I observed seemed to be earlier in the mating process, meaning I actually observed one individual fly after the other in an apparent chase. I guessed that this could have been an example of a male chasing a female individual in an attempt to reproduce. In comparison to the American Crows, I did not notice nearly the same level of territorial nature in the American Robins. The American Robins could likely nest on a gazebo that is located in the forest, since I know they tend to nest on structures such as that.

Here is the link to a google doc with the Sound Map from my field notebook!
https://docs.google.com/document/d/1UCbHv97bEFbCekbkO5-exPUiK1JkbrnTZsFbHbZtSwk/edit?usp=sharing

Publicado el abril 19, 2020 11:16 TARDE por bethanysmith512