Social Behavior and Phenology
Date:3/26/2018
Location: Winooski River
Weather: Sunny, 44°F
Time: 12:45pm-2:30pm
I chose to go to the Winooski River, close to Chace Mill, where I often see waterfowl. It was sunny and relatively warm when I got there around noon.
There were three pairs of birds. One pair was a male and female Mallard. The other two pairs were Canada Geese. One pair of Canada Geese were eating at the top of an incline on the river bank. Seemingly out of nowhere, one of the geese from the other pair began swimming quickly towards the bank. The goose then charged up the incline towards the second pair of geese. It extended its neck, opened its beak, raised its tongue, and let out a long hiss as the other geese quickly ran a few yards away. The aggressive goose did not want the other pair of geese in the same area, and the other geese got the message.
The three bird couples were in relatively close proximity to each other above the waterfall. I assume this is because there was ample food available in that area. This would also explain why the geese were being territorial. If each pair of birds were preparing to nest, because it’s spring, they must also be eating as much as possible. It would make sense that the one Canada Goose became territorial because the other pair of geese were competing in the same place for the same food sources. It would be unusual if the goose harassed the Mallards because they are not competing directly for food. It would also be unusual for Canada Geese to act so territorial during late summer and early fall because they would not be nesting at that time.
Neither the Mallards nor the Canada Geese responded to the “psssh” noises I repeatedly made at them other than quickly glancing in my direction the first few times. This is probably because both Mallards and Canada Geese are very used to human activity. In fact, I walked towards the geese to get better pictures and they seemed unbothered. I was only two or three feet away when the aggressive goose hissed at the couple I was next to.
Canada Geese have white chin straps which can create the illusion of a large eye to confuse predators. Other than this distinct marking, Canada Goose have general camouflage coloring that helps them elude predators.
Mallards have speculum feathers, the iridescent purple and blue feathers, which Canada Geese don’t have. Mallards probably have these feathers to help in the identification of potential mates and others of their species. Female Mallards don’t have the iridescent green head that the Males do and that is probably because the females need better camouflage so they can safely nest.
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