Field Journal 4: Social Behavior and Phenology

Start time: 12pm
End time: 2:45pm
Date: 03/18/21
Location: Lone Rock Point, Burlington VT
Weather: 29℉ and partially cloudy
Habitat: Semi-urban cliffs/wooded area on Lake Champlain, with a large beach nearby.

The Herring Gulls that I spotted were flying along the water. I ended up seeing five in total, but not all in a group. They flew mostly by themselves, and sometimes in pairs. I believe they were looking for food and were probably heading to the more populated beach area to scavenge. They did not seem to be interacting much as they flew. I also saw a pair of what I believe to be Common Mergansers. They were swimming in a pair so I can assume they were a mating pair. They stuck close together as they swam. In terms of visual cues, this pair of common mergansers definitely were indicating that they were focussed on each other and intended to swim together.

The Common Mergansers were definitely displaying their spring plumage, although I could not see them that clearly (they were very far away). The male most likely had his breeding plumage on display. This consists of a green head and a white body with black wings. A male Common Merganser’s non-breeding plumage resembles the females’ plumage - a brown head with a grayish body.

On the other hand, Herring Gulls do not have any significant changes in plumage year-round. There is also no difference in plumage between males and females. However, males are generally larger than females. One reason why Herring Gulls might not have a difference in plumage between males and females is because they are both very attentive parents. Usually, birds with more color variation between sexes generally have only the females take care of the young. This is because bright plumage may attract unwanted predators to the nest. Plumage that blends in better to the surrounding environment is better suited for taking care of young.

One of the Herring Gulls that I was observing was definitely foraging for food. It was skimming low over the water, in addition to heading in the direction of a populated beach. This makes sense due to the fact that it was the middle of the day. Even though the temperatures are generally increasing, it still gets pretty chilly during the evening and night. This gull is foraging for food during the day because it does not have to expend as much energy keeping warm, and therefore can use up more energy to find food. This circadian rhythm is enforced by the amount of daylight produced by the sun every day.

For the mini activity, I made a repeated “pshh” sound. This alters the behavior of small birds because it resembles a call that would be made by a fellow small bird. Birds want to know who is in their territory/habitat, so they are curious about the noise and are enticed to react to it.

Posted on March 22, 2021 04:53 AM by elenarbernier elenarbernier

Observations

Photos / Sounds

What

Herring Gull (Larus argentatus)

Observer

elenarbernier

Date

March 2021

Photos / Sounds

What

Goosander (Mergus merganser)

Observer

elenarbernier

Date

March 22, 2021 12:28 AM EDT

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