Field Journal 3
On Tuesday, March 5, I was at the Colchester Causeway from 10:28 am to 11:31 am. It was an uncharacteristically warm day for March, around 45 degrees Fahrenheit and warming as the day went on. The sky was mostly blue, with some clouds moving slowly overhead. At the beginning of the Causeway, the wind was not at all bothersome, but out on the water, the breeze was much stronger. I would say, without having written this down at the time, the wind speed was around 3 mph from the south, with gusts up to 8-10 mph.
The entrance to the Causeway trail is a forest edge. The trees are primarily conifers with some hardwoods mixed in. Houses alongside the path often showcased more edges of the treeline, where lawns were managed next to the water. On this part of the path, Black-capped Chickadees were the primary species seen. They stuck in groups and tended to fly and hop between trees. Once, we heard a Northern Cardinal call that was slightly different from other more common calls the species makes. Upon finding a group of Black-capped Chickadees, we started pishing to try and get the chickadees to come closer. At first, nothing seemed to happen, but some of the more curious birds soon found their way closer to the concrete path. However, they were easily spooked by movement and sound and retreated back into the trees. These chickadees were likely looking for food near trees, and their behavior of staying close to the treeline reflected that. If they were not, it is likely that dense areas of forest cover help protect them from larger predators. This sound likely makes them think that other small birds are around and that a certain area is safe, so they congregate closer to other birds. During nesting season, this may also mean that potential mates are nearby, and they gather for that reason.
On the water, the two most common species we saw were Buffleheads and Common Mergansers. The Common Mergansers were found both close to shore and further out into Lake Champlain. The Buffleheads were primarily found away from shore. The males of both species have a large amount of white on them, which makes them stand out and easy to spot. Male Common Mergansers also have a green head, and male Buffleheads have a black back. When there is a glare, these areas of white make the bird harder to see through binoculars. However, from above, these white feathers would make them easy to see as well. The females of both species are slightly darker. Female Common Mergansers have a red head with a gray back and wings and Buffleheads are primarily gray-black. While this coloring makes them easy to spot with a glare, from above, they may blend in well with darker water. the lighter gray back of female Common Mergansers may make it more beneficial for them to be closer to shore, where the water is not as dark as in the center of the lake. Female Buffleheads may have a better time in the center of bodies of water because their feathers are so dark, and it makes them incredibly hard to see from above.
Buffleheads are also much smaller than Common Mergansers, even if they are both diving ducks. These birds may also use their plumage to their advantage. If they can remain safe from aerial predators while looking for food, they can manage their high metabolism and fly when needed. Diving also requires a lot of energy, so remaining in an area with ample amounts of food is also necessary.
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