Field Journal 4 - Social Behavior and Phenology

Date: 3/21/21
Start time: 9:45 am
End time: 11:00 am
Location: Burlington Waterfront, Burlington VT
Weather: 38F, 5 mph wind, clear sky
Habitats: Lake, Lakeside, Urban Area

A lot of the birds there were seen, such as the Common Goldeneye, Common Merganser, American Black Duck, Mallard, Ring-billed Gulls, Canada Goose were hanging out together in Lake Champlain. The birds that were seen on land were also hanging nearby others and in groups of two or three of their own species. In the case of the House Sparrows that were seen/heard there was one on either side of a parking lot. I would hear one chirp and then immediately afterwords the other one would chirp, and they would go back and forth. This could have been because they were communicating their location to one another, determining territory boundaries, or telling each other about food sources/dangers nearby. With the Common Grackles that were seen, they have a variety of different calls that I heard. Each call meaning a different thing depending on what exactly they're trying to communicate to others of their species - or other species even.

The Common Grackles are much smaller in size when comparing them to a Canada Goose. The birds plumages also differ greatly. The Common Grackle has a fully black body with an iridescent blue head and piercing bright eyes. The Canada Goose on the other hand has a brown/white back, white stomach, a black head and neck and a white cheek patch. The Canada Goose goes much further north than the Common Grackle. Its lighter plumage and larger body play a key role in the birds ability to survive colder temperatures. Larger body sizes means that there is less surface area, and lighter color feathers work for both the geese that choose to stay during the winter, and those that migrate south. In warmer climates, lighter feathers keep the birds cool and in colder climates lighter feathers help them blend in and hide from predators. With the Grackles their dark plumage could be beneficial for both those in colder weathers and those in warmer weather as well. Those in cooler weather during winter get the benefit of their dark feathers warming up in the sun, and in the warmer weather during the winter those Grackles get the benefit of the sun/heat killing ectoparasite on their feathers.

One individual bird that I observed was a male Mallard. This mallard was in his breeding plumage with the iridescent green head and lighter colored body, this corresponds correctly with their annual cycle. He was also tipping his head into the water and dabbling. This corresponds well with his circadian rhythm because this was early afternoon when the sun is warming them up and allowing them to do these activities without having to exert more energy to stay warm.

Spishing was attempted and the two Common Grackles that were sitting in the tree above flew over head and landed in a tree on the other side of the path. Spishing works to an extent because birds, similar to lots of other things, are curious creatures. It might sound similar to other alarm calls made by other species or animals, and when birds hear it they want to investigate to see what the threat is, or they want to flee the scene before the threat finds them.

Julkaistu maaliskuu 22, 2021 12:49 AP. käyttäjältä esmith7