Field Journal #4

-3/21/2021
-2-4 pm EST
-Redstone Pine and Harris Green
-Sunny day, Light wind, 52 degrees Fahrenheit
-Redstone pine made up primarily of red pines and the Harris green could be considered a small open field.

While hammocking in the redstone pine I was able to witness a myriad of different bird species and both their interactions with myself and each other. One of the species that I saw the most of was the notoriously curious and interactive black-capped chickadee. Several of them landed right above me multiple times and let out their distinctive chick-a-dee-dee-dee call. Most often this is a call to let other chickadees that there may be a predator nearby. In fact, some studies indicate that chickadees utilize slight variations in this scolding call to communicate the size and threat of the predator. When the Black-capped Chickadees would appear above me they would often let out a call and then disperse to areas that were further away but where I was still in their eyesight. It almost seemed as though they were coming to evaluate what level threat I was and then leaving. The second and third times that they came close to me I employed the "pishing" technique. First I used a repeated "pshh" that was slightly high pitched, which in this case seemed to drive them away. The second time I used a lower pitch continuous noise to which they initially came a bit closer and then dispersed. The main reason that spishing, if done correctly, can attract birds is that it can sound like a scolding call to some birds. It attracts them because they interpret it as a warning of a nearby predator that they should be aware of. There is also some speculation that spishing can attract insectivore bird species because it can sound like the wingbeats of a large insect.
The other bird species that I was able to observe the most closely was an individual Downy Woodpecker. This woodpecker was exhibiting foraging behavior right above me. I could tell that this was foraging as opposed to drumming because it was irregularly timed and the Downy Woodpecker moved around often. Drumming is regular pecking sometimes interspursed with calls and is used to both establish territory and attract females. As we move into early spring aka Downy Woodpecker breeding season drumming should begin to become more common. As breeding season begins many aspects of the Downy Woodpecker's physiology and behavior will begin to change in accordance with its circannual rhythm. Their testes will become wider, the drive to breed will begin, and drumming will become a prevalent behavior.
The plumage of several of the birds that I saw displayed differing evolutionary advantages. I briefly saw several house sparrows. These sparrows have most brown and neutral tone feathers that give it some ability to camouflage in a forest setting. Conversely I identified a male Northern Cardinal which has bright red coloration. This bright color that makes it stand out likely evolved over time through sexual selection as females chose to breed with males with brighter coats because it indicated that they were healthy.

Publicado el 22 de marzo de 2021 por