maggiegrady's Journal

Date: 3/3/2024
Start time: 17:13
End time: 18:15
Locations: Redstone campus, Redstone Pines
Weather: 44 F, clear, 5 mph south-facing wind
Habitats:

1. Lawn with some deciduous trees and evergreen shrubs
2. Mature Eastern white pines with little understory, magnolia shrub, some mature-to-intermediate deciduous trees nearby with more understory

This week I wanted to experiment with timing, so I took my walk in the evening to see if I would encounter different bird species or behaviors. If I could have done it over, I likely would have gone about a half hour earlier, as noticeable bird activity almost completely stopped around 17:45 when the sun set. This is likely because the diurnal birds' circadian rhythms are set to sleep around sunset.

Despite this, I did encounter some interesting birds, particularly two Common Ravens and a Cooper's Hawk. According to All About Birds, Common Ravens typically pair up between the ages of 2 and 4-- before that time, young ravens often group up and jockey for territory. I found this interesting because I distinctly remember seeing a large group of ravens around campus last year, so I wonder if the ravens I just saw were members of that group and thus recently entered the breeding stage.

The raven pair was perfect to examine for modes of communication, as they are a very intelligent species. Initially, I saw only one raven sitting atop a water tower and making a strange, repetitive noise, then occasionally cawing. Soon afterwards, the raven flew into the pines, and I noticed the second one nearby. Therefore, I theorized that the odd sound was the first raven calling to its mate. This video I found sounds almost the same, which provides evidence to support my hypothesis: https://www.youtube.com/watch?v=EOEZq3aRL_8
Additionally, I observed one raven gathering pieces of twigs and gesturing with them at the other raven, which I perceived to be an attempt to catch the others attention and perhaps a question—such as whether the sticks were of good enough quality for the nest.

The Cooper’s Hawk I encountered appeared to be under a year old, as it still had the signature light breast and brown streaking of immature plumage. Cooper’s Hawks are a forest-dwelling species and active hunters which mainly prey on small to medium birds, so their plumage must provide adequate camouflage before they strike. Thus, they are mottled brown and white in immaturity and become blue-gray and reddish when they mature. Conversely, Common Ravens are mostly opportunistic feeders, eating everything from carrion to eggs to unattended human food. They do not rely on camouflage to survive, so their plumage is very dark, likely because the melanin provides strength to their feathers.

I did not witness the Cooper's Hawk catch anything, but it did appear to be attentively looking for prey in the vicinity as it perched on a high branch. As I did not encounter any flocks of small birds, I attempted to spish the hawk-- it was not particularly amused or disturbed. Eventually, the bird glided away further into the trees, likely to investigate for prey or head towards a roosting place, as it was beginning to get dark.

Date: 3/24/2024
Start time: 12:12
End time: 13:21
Locations: Redstone campus, Redstone Pines/Interfaith Center
Weather: 30 F, sunny, 7 mph south-facing wind
Habitats:

1. Lawn with some deciduous trees and evergreen shrubs
2. Mature Eastern white pines with little understory, magnolia shrub, some mature-to-intermediate deciduous trees nearby with more understory

Of the ten avian species I observed, six were resident species in Vermont. These included House Sparrows, Black-capped Chickadees, Tufted Titmice, Red-breasted Nuthatches, Common Ravens, and European Starlings. These are all birds that I have previously observed in winter, although House Sparrows and Common Ravens seem to have become more prevalent now that their breeding season has begun. Resident species typically forego migration because enough of their populations can find food and shelter to survive overwintering, so migrating is not worth the risks and energy input. To survive the winter, resident birds instead employ adaptations such as entering a hypothermic state at night to conserve energy and flocking to share body heat.
The four other species that I observed on this walk were facultative migrants: Song Sparrow, Cedar Waxwing, American Robin, and Ring-billed Gull. I have previously observed these species, but never on a dedicated bird walk and only in the past two weeks. They are all short- to medium- distance migrants and likely came from the southeast or mid-Atlantic U.S. The weather conditions this weekend have been quite cold (about 15-35 F) and very snowy, so less than ideal for migratory birds. Therefore, I assume these birds migrated north a couple weeks ago when it was much warmer, or else were so far away that they relied on timing rather than weather to begin their migration. There has been a massive influx of American Robins (I probably saw at least 50 on my walk today) which are overcoming the snowy conditions by foraging in trees and a grass patch on the Redstone green that presumably straddles a heating pipe which melted the snow.