Field Observation 3: Social Behavior and Phenology

Date: March 20, 2019
Time: 12:00-3:00
Location: Shelburne Farms (Shelburne VT)
Weather: Sunny, 50 degrees F, light wind
Habitat: Open field, sparse trees, open lake water, dairy barn

On this bird walk on the first day of spring, the birds I observed were behaving accordingly. The first birds I encountered were American Crows. I noticed four of them foraging in a field where the snow had melted. I could not tell what they were eating, but it may have been seeds, or perhaps some sort of insect or worm, however this is less likely because of the time of year. Throughout my walk, I observed many crows also doing this. The crows were also very vocal. During the 3 hour period I was out, it was rare that I didn't hear a crow calling. I suspect the calling was to communicate with other crows, since they are a fairly social species. These vocalizations were possibly related to mating. Males might have been calling to females to get attention, or to other males warning them to keep away. Some of the more vocal crows were sitting up in trees rather than staying on the ground, and these are the ones that might have been calling for mating related purposes.

I then heard a flock of Canada Geese flying above me. They were fairly high up in the sky. They were most likely returning from their migration from more southern areas. Again, it was rare that I experienced a period of time where I heard no geese calling. There were several flocks that flew by as I was on my walk. Geese flying in formation call to keep track of each other as they fly.

Further along my walk I saw a species which I could not identify sitting at the very top of a Norway spruce (EDIT: it was an Eastern Bluebird). The bird was slightly smaller than a robin and had a white underside, brown-red breast, and a grey back and head. The bird was periodically calling. This behavior looked like the bird was a male setting up his breeding territory, which aligns with the time of year. Because he was sitting at the highest point around, he was showing his dominance to other males and was able to see any conspecific that may come by. His vocalizations also seemed like they were to communicate with other males telling them this was his territory.

I then saw an American Robin foraging in a field, and when I approached it flew into a nearby buckthorn to escape my possible predation.

As I walked towards the dairy barn, I heard a lot of bird activity. I entered to see a lot of House Sparrows and Feral Pigeons in the rafters. It appeared both species were preparing to nest or nesting, given the frequent calls and the presence of nests from past years. The pigeons would fly from rafter to rafter to perch next to other pigeons. I saw both male and female pigeons. I also saw both male and female house sparrows.

Leaving the barn, I spotted a Red-tailed Hawk circling on thermals extremely close to me. Because of the time of year, I suspect the behavior may have been a male setting up territory. However, I saw another hawk a little later flying close to the ground surface, which looked a lot more like foraging.

Just outside the dairy barn, I heard a flock of European Starlings up in a white pine. I looked up and saw at least 20 of them perched together at in the uppermost branches. They were being extremely vocal. I suspect this behavior has to do with mating.

As I walked towards the water, I noticed a lot of birds out on the lake. Although most of the water was frozen over, there was one small area that had open water due to a pressure ridge. In the open water were many Common Goldeneye, both males and females. Also present were Canada Geese. As I was watching these birds, I saw three Common Mergansers fly by. All of these birds are most likely returning from migration and seeking out any open water they can land on to prepare for breeding.

Comparing plumage: The male House Finch has a red coloration, that stands out especially well this time of year. His coloration is for mating purposes to get the attention of females. Conversely, the male House Sparrow is more drab. His head has a reddish tinge, but is mainly brown. Although he is not as obvious to females, he is more likely to not be seen by possible predators.

Mini activity: I was unable to get the attention of the House Finches I tried "phishing" to. I might have accidentally walked too close and scared them too much.

Publicado el marzo 21, 2019 05:02 TARDE por samuelmcclellan