Field Journal 7: Reproductive Ecology and Evolution

Date - 4/24/21
Start time - 9:03
End time - 10:57
Location - UVM Campus
Weather (temperature, wind speed/direction, precipitation) - 54 F, 11 mph SE wind, mostly cloudy at beginning of trip but sunny by the end
Habitat(s) - college campus/residential area, retention pond, open field

One of the first examples of territory selection I saw on this trip was an American Crow chasing off a Red-tailed Hawk from its area above campus. This was surprising to me because normally I would think of a hawk being more aggressive than a crow, since it's a raptor, but I guess in this case it didn't matter. When looking for any birds nesting, specifically American Robins in yew and other shrubby bushes, it was pretty difficult to find anything until we found a robin nest in a small tree of of Spear St. This was especially weird because it was a bare hardwood tree relatively close to a busy road that didn't really offer any protection for the nest. Maybe there was a scarcity in good nest habitat for that individuals territory. This nesting habitat is very different from Red-winged Blackbirds. We saw a few of these by the retention pond behind Redstone campus, where there are plenty of grasses and cattails that blackbirds like to nest in.
Speaking of these Red-winged Blackbirds, I think we saw some kind of territorial or mating display at the retention pond. On one side there was a male singing continually while at the other side was a female and another male. I couldn't tell if the singing male was singing to protect his territory from the couple or if he was trying to get the attention of the female, but my guess is the first option since this was a prime nesting habitat. This most likely indicates that he is more fit compared to the other male since he is defending a territory that he already possess from another male.
Another species we saw on this trip was the Turkey Vulture. Because Turkey Vultures are so large, I would imagine they have to find large trees or hollowed out snags to nest in. They would also need to find large sticks instead of the small twigs that most smaller birds use for their nests. Vultures could probably find this kind of material in old hardwood or pine stands where there would be enough old trees or snags to take sticks from.

Posted on 26 de abril de 2021, 08:02 PM by emma2forsythe