Field Journal: Redstone Campus

Date: March 8, 2024
Start Time: 3:26pm
End Time: 4:30pm
Location: Blundell House and Redstone Pines, Burlington, Vermont
Weather: Partly cloudy, 44℉, 7mph wind heading SE
Habitat: Urban with old coniferous canopy trees and some suburban landscaping trees

Linked Observations:
American Crow- 1 Observation Site
1) I spotted one American Crow at this point and simultaneously heard it cawing from a tree across the road.
Black-capped Chickadee- 1 Observation Site
1) I heard a lot of cheeping and twittering going back and forth, which I identified as a Black-capped chickadee based on the tone and some of the longer songs.
American Robin- 1 Observation Site
1) I heard one American Robin which I identified from a far away chirp that had the same tone.

For this field journal, I want to focus on one site on the Redstone campus I sat at for a long time near Blundell House. This area was at the intersection of the old pines with tall canopies, the road which breaks out into a grassy area, and the back of a suburb which has a fair amount of landscaped trees. At this site, the first sound that caught my attention was constant twittering which I couldn't identify at first. What allowed me to initially come up with an identification was a two-toned shrill chirp which sounded identical to the dee-dee-dee of the Black-capped Chickadee. However, this twittering was not characteristic of their usual songs that I know.
I'm not sure how many chickadees were involved in this communication, but given it was late afternoon, I didn't expect them to be very active. However, this twittering could be a sign that they aren't active in mating or other rituals where they would usually use their distinct song. Instead, they may have been twittering back and forth just to communicate their presence as communication is very important for birds to understand if large predators are in their midst. Generally, I would say this chirping sounds like the human version of chatting- it's simply normal communication between birds to interact and let each other know they are present. The American Crow that was cawing was likely doing something similar but its call is a little louder and uniform across the board. These generic sounds that both bird species were making are likely bird's way of keeping in contact throughout the day without communicating something extremely specific.
In this same area, I pursued the mini-activity, and it seemed the birds quieted for a second and then the Black-capped Chickadees responded with more intense twittering. I would guess they might respond to this pshhhh sound because it mimics that of wind rustling vegetation or insects calling. These sounds might be enticing to birds because they are a sign of a food resource potentially being present.
At a different site on the Redstone campus, I spotted an American Robin, which I could only vaguely hear earlier. This Robin had a darker grey head and tail with a medium grey back and burnt orange underside. This robin was perched toward the top of a tree and soon flew to perch on a nearby residential building. It was potentially looking for food at the time although I can't quite be sure because it was only perching for short amounts of time and then moving to a new location. The plumage of this robin is likely useful for it to blend into forested and urban environments with its slate colored back, while I would assume the orange chest is used to attract mates as it's a flashy color that doesn't camouflage.
Comparatively, I also saw a Black-capped Chickadee flying to one of the large coniferous tree trucks, where it quickly perched and then flitted to another tree trunk. This bird had its distinctive black cap, brownish-grey wings, a whitish-brown breast, and triangles of white around the black on its face. These plumage colors are much harder to see against the backdrop of trees than that of the robin, which is likely a survival skill given the small size of the chickadee and its frequent settlement around wooded areas. Furthermore, the fast fluttering movement of the chickadee may allow its colors to blend together into an even earthier tone that allows it to better blend into the backdrop. Given the Black-capped Chickadee's small size and neutral colors, it seems camouflage is a major priority in survival skills for this bird, which would make sense given how active they are during the day. The American Robin on the other hadn't is larger and flashier meaning they may value mating rituals more greatly than hiding from other species as a survival skill.
When I saw each of these birds, they were moving from place to place, which indicates to me they were maybe ramping up for dusk when activity picks up. They may have also been finding more inconspicuous spots to sit before this time of high activity. Furthermore, they may have been trying to avoid the human activity going on in the area. Therefore, I would say each bird was in a transition period between high activity functions such as intense foraging, and was therefore moving to improve survival. The constant perching for each was likely a way of reducing energy usage in order to preserve it for peak activity periods. On the flip side the constant movement from perch to perch may have been a means of warming up and increasing metabolism in preparation for high activity, but this seems less likely.

Posted on March 8, 2024 09:20 PM by nlhardy