5/2/23 Field Journal: UVM University Green
2:30-3:30pm, 5/2/2023, UVM University Green, Burlington, VT, cloudy, ~54 degrees Fahrenheit, open green with scattered trees.
Bird observed: 3 Chipping Sparrows, 5 Ring-billed Gulls, 3 Song Sparrows, 4 Black-capped Chickadees, and 2 American Robins
On my trip to the UVM University Green today, I focused on the reproductive ecological and evolutionary factors of birds. When thinking about mate selection for birds, singing is the first thing that comes to mind. Especially during the breeding season in Spring (like right now!), singing from birds is so common and is a huge part of finding a mate.
I also thought about nest and territory selection and observed, even in the birds I saw today, how they pick their homes by considering food supply, mate availability, temperature, and less risk of threats. In the birds I saw today, many of them had nests high in trees or deep within thick shrubs around the green. I can imagine that different bird species require different things, so one might find it more suitable to live closer to the ground in thick coverings while another might find it better to be higher in trees. Additionally, not all birds use the same resources so depending on how much of something they need, they might find different territories to live for convenience to their species.
When looking at the territories that different bird species were defending via singing, it was interesting to compare birds of the same species and whether or not that territory they were defending was a prime or poor compared to others. In the Chipping Sparrow, I saw one singing in a poor location where there were plenty of threats nearby and it was surrounded by buildings. However, when on the green, I heard/saw another that was located in a conifer and in a green area with not as many threats and more availability to food and other resources. I would assume that birds who defend poor territories have a lower fitness than those who defend prime territories because of more threats, less availability of food/other resources, etc.
Lastly, I wanted to look into what birds used for nest building. When looking at the American Robin, its nest seemed to be made with twigs, grass, and other natural outdoor materials. In forested and grassy areas, I can imagine it would be pretty easy to find these materials for nest building, but I also think that birds take advantage of living near human populations by also utilizing things that are dropped by us humans.
