Date- March 25th, 2024
Start time- 10:50 am
End time- 12:15 pm
Location- Salmon Hole on the Winooski River, Burlington VT
Weather- ~35° F, little wind, no precipitation- sunny, minimal clouds
Habitats- Riparian habitat (eastern cottonwood, silver maple, some evergreens such as eastern white pine, American basswood), riverine habitat, some cattails; site is next to a sewage plant (?) so some pollution/lots of noise pollution
For this field journal assignment, I went to the Salmon Hole Wildway on the Winooski River. I have been to this site often, for leisurely and educational purposes, so I was excited to see what I would find while birding. I walked along the path the entire time (although there isn't much space off the trail), as the snow was quite deep and I didn't want to create more disturbance than necessary. I immediately heard some Northern Cardinal, Tufted Titmouse, Black-capped Chickadee, American Crow, and Song Sparrow calls once I entered the area. I also identified a White-breasted nuthatch by sight, along with a Dark-eyed Junco, an American Robin, and an American Goldfinch. Regarding water birds, I identified a Mallard (male and female), a Canada Goose, and several Ring-billed Gulls on the river. All of these birds largely remain in VT for the winter (as far as I know, as I have seen them all throughout the season), and they have several strategies to do so, from obtaining food from reliable sources (bird feeders, via scavenging, winter berries, etc.) I'd wager that the cost of migration energy-wise outweighs the challenges of remaining in the area for the winter, meaning it is more cost-beneficial to overwinter in the state despite the changing temperature. They also can self-insulate by puffing out their plumage (which I've seen several of these species do at bird feeders and in the field). Another physiological adaptation to aid these species in over-wintering is going into torpor and lowering their body temperatures to conserve energy and resources. A behavioral adaptation that could also assist in this endeavor is the use of cavities in trees and snags, where heat is better trapped. Back to my species count, I had trouble keying out a song I heard, so I used Merlin ID, which registered the bird as the Carolina Wren. Researching this further, there is a chance the app was correct, because the species has been found in Vermont, but it's also possible that the app was wrong, so I'm still not 100% sure what bird it was. Other birds I identified via sound were the Downy Woodpecker, and possibly a Hairy Woodpecker (although I didn't get a concrete enough view to be 100% confident the beak was the length of a Hairy Woodpecker).
One species I identified by sound that qualifies as a facultative migrant is the Red-winged Blackbird. I know some individuals remain in Vermont for the winter, but the vast majority (as far as I can tell) migrate south toward warmer weather. Several changes in the environment facilitate their complete return to Vermont, namely the increase in food resources (insects), preferential/breeding habitat (wetlands and grasslands), and increase in temperature more broadly with springtime. A disadvantage of arriving this early in Burlington is that the weather is still quite dynamic (as evidenced by the recent snowfall), so their habitat requirements could be less consistent than they need. After researching, I also found that males generally arrive first, to establish territories for mating and future breeding sites (https://vtecostudies.org/blog/red-winged-blackbirds-signal-the-arrival-of-spring/). To determine a basic migratory distance for the species, I used Williamstown, MA as an overwintering site. This would make the travel distance ~140 miles from Burlington (quite impressive!).