3/13/2019- Ball O'Brien Park

My walk took place on Wednesday March 13, 2019, from 4 PM to 5:45 PM. The habitat around the trail was primarily loose shad, with bittersweet vines and green briar thickets providing intermittent patches of dense cover. The weather was overcast, with no precipitation, and the temperature was about 4 degrees Celsius/40 degrees Fahrenheit.

One of the first things that I noticed while heading down the trail was that right on the other side of the tree line of shad and brambles was an apartment complex with several well-stocked bird feeders. There was a group of multiple male and female house sparrows, some red-winged blackbirds, and at least one blue jay going back and forth from those bird feeders to the tree line. The house sparrows in particular were calling back and forth and vocalizing loudly in general. They seemed to be living in the stands of shad instead of simply visiting for the use of the bird feeders, like the red-winged blackbirds.
It was hard for me to tell whether there was simply one group of house sparrows moving around within a single territory, or more than one groups who were living close to one another with distinct spaces of their own. It probably would have been easier to tell if I wasn’t so close to them directly. In addition to their usual ‘chirp’ calls, I also heard some sharper calls that may have been alarm calls. These sounded more like ‘cheer’ and were a bit louder than the usual chirping calls.

I heard the downy woodpecker before I saw it, as it was drumming on wood to forage for food. When you compare the plumage of the woodpecker to one of the male house sparrows I saw, there’s a marked difference. The house sparrow is not brightly colored, although it has a distinct ‘bib’ marking of darker feathers under its beak that makes it easy to recognize. This makes it easier for these sparrows to camouflage themselves in the denser foliage. On the other hand, the woodpecker’s contrasting black and white plumage serves to break up its outline and can provide useful in thermoregulation.

Lastly, I chose to focus on one of the red-winged blackbirds to study individual behavior. It was going back and forth from the bird feeder to a single shad on the edge of the field and then back again. Since red-winged blackbirds are a short-distance migratory species and are just starting to come back to the island after the winter, it probably appreciated the bird feeders as a source of food, especially since the weather until then had been unseasonably cold from what they were likely used to.

The mini-challenge was mostly unsuccessful at attracting birds, as no matter the timber or pitch of my pishing it scared the house sparrows off. There would be a lot of alarm calls and then it would take a while for them to go back to what they were doing and release their guard again. I think that birds react to this call - and in different manners depending on the bird and the pitch and timbre of the call - because it resembles calls of their own, whether a positive identification or closer to a warning call. It would also be interesting to see if different birds reacted differently to the same noise in different pitches.

Publicado el 25 de marzo de 2019 a las 07:36 PM por ivdupont