Bird Walk #3
On March 9, 2020, I walked on the Head's Pond trail in Hooksett, NH from about 4:45 pm until 6:30 pm. The weather was warm in the high 50s and the sky was relatively clear and sunny.
The visual and auditory cues birds use to communicate within and between species can tell us a lot about what they are trying to communicate. For example, I'll compare the plumage of the Mallard I saw to the plumage of the Black-capped Chickadee I saw. The Mallard had a brightly colored green head, which was very apparent and gave away his location so we could easily spot him. The strong sexual dimorphism of the green head in this species indicates not only the sex of the bird, but perhaps the fitness of the male Mallard. In terms of behavior, the Mallard was resting with his bill tucked into his wing, as there were no females present in its' vicinity to try and court. Another possible reason the Mallard was resting, is that it was not quite breeding season yet at this time and it had not yet decided to seek out a mate. In the case of the Black-capped Chickadee, its' plumage is more discrete, not sexually dimorphic, but still distinctive. Perhaps this more discrete plumage allows it to blend in more easily with its' environment and avoid predation, while also serving as a measurement of fitness when breeding. The Black-capped Chickadees seemed to rely more on audio cues to communicate with the birds around them, as the sun began to set the frequency of their calls increased dramatically so as to communicate who was around them.
I tried to practice some "spishing" but it did not prove much success for me. I do understand why it would normally though, as the presence of chickadees could suggest viable habitat and resources. Chickadee calls also tend to be for alarms, so other birds may come when a chickadee calls to establish the degree of threat or predation nearby.
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