Bird walk 4/8/20

My walk took place on April 8, 2020, at 2:20 pm. I walked to a park near my house in Chatham, NY. It was about 50 degrees and somewhat overcast, but cleared up during the time I was out. The park itself is next to a moderately traveled road and features a pond, some playground equipment, soccer fields, and a wooded trail along a stream. I happened to be the only person in the park for most of the time I was there.

When I first arrived, I noticed the usual species that were feeding along the edges of the soccer field: American robins, a downy woodpecker, brown-headed cowbirds, and common grackles. There were also three Canada geese on the pond, but soon after I arrived a scuffle occurred and one goose was chased off the pond and flew out of sight, leaving the other two, who were obviously a pair. I then approached a marshy area with a dense understory and a few larger trees. As I watched and listened around here for a while, I observed an American goldfinch, black-capped chickadees, a large band of cedar waxwings, dark-eyed juncos, song sparrow, house sparrows, and a northern cardinal.

On my walk back to my house, I kept looking out for birds, and along the way I observed two circling turkey vultures, a hairy woodpecker, and a couple blue jays. There was also a strange incident in which I heard an common raven call, and then it flew low overhead while being chased by an American crow. The crow dived at the raven and I could hear the sound of their wings hitting each other.

Of the 20 species I observed, I compiled them into these categories, according to All About Birds:
Do not migrate: northern cardinal, common raven, black-capped chickadee, common raven, hairy woodpecker, downy woodpecker, rock pigeon, blue jay
Facultative migrants (possibly year-round in Chatham): common grackle, brown-headed cowbird, dark-eyed junco, American goldfinch, song sparrow, house sparrow, cedar waxwing, American robin, American crow, Canada goose
Obligate Migrants: eastern phoebe, turkey vulture

Of the year-round species, many of them have evolved a very broad diet, like the common raven who is an omnivore, the black-capped chickadee who will eat plant matter as well as a variety of insects and seeds, and the woodpeckers, who eat the insects in trees that don't die in winter. As a result, there is no need for them to migrate, as they are able to make do with what is available. Additionally, these species' diet usually contains fat- and protein- rich foods, like seeds and insects, which helps them to store fat and stay warm in the cold winter. They also seem to be some of the least fearless species, which may give them a behavioral advantage for survival. For example, they don't mind living around human structures, since they provide food resources.

As for the facultative migrants, these species move when food is scarce. Take the cedar waxwing for example. This species eats primarily fruit, so when all the fruit in the fall is eaten or rots, they must move south to areas where plants are still fruiting. Then, they return north again as new fruits grow and become available. Because they follow the seasonality of fruit, they do not winter in Canada, but move south to the United States. Some birds in the northern part of the United States will also migrate to the southern half of North America, even as far as Panama and Costa Rica. The band of cedar waxwings that I observed may still be traveling north, or they may have reached their destination for the summer.

I only observed two species that never winter in Chatham: the eastern phoebe and turkey vulture. As a very early migrator, eastern phoebes have already gotten a head start on feeding and breeding in New York. However, because they always migrate, it may take them a few weeks to make up the energy lost on migration. As for the turkey vulture, the advantages and disadvantages are probably similar, though they occupy a very different niche than the phoebes. These two species combined traveled about 2200 miles in their migration north to Chatham, Ny.

Publicado el 09 de abril de 2020 a las 04:06 AM por natalya-h