April 20, 2020

Monday, April 20, 2020
Wallingford, PA
(Habitat: backyard bird feeder; suburban deciduous forest edge/field)

6:00 pm – 7:30 pm: It was a warm spring golden hour, about 60 degrees F, with clear skies and a slight wind from the southwest. For this journal, I went to the field/forest edge behind my house and watched. There was a lot of singing going on this evening! When I arrived at the field, I heard the songs of Song Sparrows, American Robins and Northern Cardinals, and the calls of House Sparrows, White-breasted Nuthatches, Red-bellied Woodpeckers and House Finches. Standing in the field, all of the vocalizations were coming from the surrounding foliage—whether from the finches and sparrows in the arborvitae trees lining the edge of the field or the calls that came from the woods—the only sounds I heard in the field were from birds flying overhead. Given the time of day, I’m guessing the birds were settling in for the night and perhaps focusing on territory defense and courtship? It would make sense that the safest nesting sites would be somewhere with either foliage or taller grasses to serve as cover. I noticed that except for the species I observed in the line of arborvitaes (House Finches, House Sparrows and Song Sparrows) (the habitat closer to manmade structures) were mostly ground foragers and nest on the ground and/or in manmade structures, while the species I observed in the woods were largely tree nesters.

I kept seeing one particular Song Sparrow that would fly between a few different trees, but almost always sang from the top of a tree or one of the outermost branches. I’m not sure whether he was singing to attract a mate or to defend his territory, but either way, he was making his presence quite known! According to All About Birds, Song Sparrows nest and forage on the ground, but males sing from higher perches, which explains why I see them singing from telephone wires and treetops. I heard other Song Sparrows singing from other directions, but I don’t recall seeing any others in that particular stretch of trees, so I’m wondering if that was in fact his territory, and if a nest was on the ground nearby. These trees may be a prime territory—their low branches provide cover for nests on the ground, allow easy access to the field for foraging and are currently in a relatively undisturbed area, since the playground is not in use due to COVID-19. However, these trees also always have flocks of House Sparrows and House Finches in them, and while they may not compete with Song Sparrows for nesting sites, they may compete for food resources and they can also be noisy, potentially making the area more obvious to predators. But overall, I believe this would make a good territory and likely reflects well on this male’s fitness.

While I was making my sound map, I observed two American Robins that appeared to be communicating to each other across the field from two different trees. I think I startled one when I walked by a cluster of vines growing on a fence around the playground that the field belongs to—the robin had a long piece of grass in its beak that must have been for a nest! I don’t believe robins tend to build nests so close to the ground, so I don’t think the nest was in those vines. But in case it was nearby, I sat down underneath an ornamental tree planted near the playground and I noticed that the first robin was “cucking” in my direction, perhaps not at me, but to another robin that was directly above me in the tree! I couldn’t determine the sex of either, but if the one I startled was carrying nest material, I would guess that it was a female since female robins do most of the nest-building. The grass looked like it could be from the sedges that grow in our neighbor’s yard, which were recently cut and have been blowing around the area.

Sound map: https://drive.google.com/file/d/1b3bvlBKIkTJvEqUeN8tVM8XguYuuhbu5/view?usp=sharing

Publicado el 22 de abril de 2020 a las 09:37 PM por mreilly20