Field Journal Assignment 4

On Wednesday morning, March 25, from 11 am-1 pm, I engaged in an observational walk at Fresh Pond in Cambridge, MA. The temperature was 40 degrees Fahrenheit, with overcast clouds and a lot of wind. I started my walk on the path that surrounds the large pond, but it was so windy and cold that I soon diverged on to the golf course area that lies next to the pond. This area has many fewer people and is more protected from the wind, so I was able to see many more birds. The golf course has many small bushes, small ponds, and variously spaced out trees, but it is mostly an open grass area.
First, I saw many American Robins on the open grass all seemingly scavenging for food. For the most part, they were well spaced out and not interacting which each other through calls or other methods. However, I heard sudden louder songs and calls and noticed that two American Robins were engaging in a fight (picture attached in observation). I did some research and discovered that American Robins can be very territorial. It is possible that one of these birds infringed on the other’s territory, which resulted in the fight. I also learned that American Robins often sing when they return to their territory, which would explain the song and calling I heard right before the fight ensued. It is possible the American Robin was trying to warn the other to back off as well. Birds often use songs to establish their dominance in their territories and to tell other birds to back off. While fighting, the American Robins opened their wings, even while just standing, this visual cue shows the other that they are large and willing to fight. When they stopped fighting, one of the robins visually became much smaller, closing his wings. This cue shows defeat and backing down.
Moving along the golf course, I noticed two Mallards, two Canada Geese, and one Great Blue Heron. The Mallards were resting in the water’s edge of a pond and the Canada Geese were resting just on the banks of the same pond. I think that is is possible that these two pairs were mates, since the Mallards, at least, were of the opposite gender. It is also getting closer to breeding seasons, which also makes it likely that these two pairs are mates. This behavior of finding a mate is part of these species' circannual rhythm. They repeat the same breeding activity each year, based on the photoperiod. The photoperiod this time of year is allowing for more sunlight per day to occur, which can help trigger breeding activities for Mallards and other birds.
Moving along, I came across a more densely forested area of the golf course. I noticed a group of three Common Grackles in a tree, that flew off as I approached closer. I noticed another black bird on the ground and took a picture. As the bird flew off, I noticed that it was not another Common Grackle, because this bird had red coloration on its wings, making it a Red-Winged Blackbird. While it was on the ground, its red spots had been concealed allowing only for a small white line to be seen on the wing. This red coloration is an example of bold coloration that can be used to attract a mate. I did some research and discovered that in order to attract a female, male Red-Winged Blackbirds perch and open their wings in order to show off their red wings. This plumage pattern is very different from the House Sparrow, for example. House Sparrows have more of a cryptic coloration on their backs to camouflage into their surroundings. Female Red-Winged Blackbirds, however also have this cryptic coloration, which makes sense because the males are the ones who are attracting the mates, while the females have to camouflage while protecting the eggs.

I didn’t encounter any Chickadees this trip, so I tried Sphishing near some foraging American Robins. This sound resembles a mobbing sound and a potential threat to birds. So, it attracts some birds who want to know the cause of this threat and it also makes some birds flee because they do not want to be hurt by this threat. The American Robins I tried it on did not seem to care that much. A few of them changed their stance to an alert upright position to listen to my sounds and a few hopped away. Next time, I will try it near chickadees or near a more dense bush area.

Posted on 25 de março de 2020, 05:25 PM by miahandtereinecker