Field Journal 7: Reproductive Ecology and Evolution

Time: 6:00pm - 7:30 pm
Date: 4/18/20
Location: The Salmon Hole, Winooski
Weather: 52 degrees F, partly cloudy, slight breeze
Habitat: Riparian Habitat

Species: Double-crested Cormorant (2), Herring Gull (15), Canada Goose (2), Red-winged Blackbird, American Crow (3), American Robin (1), Common Merganser (2), Song Sparrow, Red-tailed Hawk, Black-capped Chickadee (3), Northern Cardinal.

On April 18th, I decided to go to the Salmon Hole to bird, and I also brought a fishing pole with me so I could take some time to relax and enjoy the sunset. This turned out to be a great birding trip, and I saw and heard lots of different species, both while I was walking and while I was standing still to fish. In terms of mate selection and territory selection, I spotted a pair of Common Merganser, one male, and one female, which were moving upstream past me while I was fishing, and then turned around and returned back to the area where I first saw them. I had also observed a pair of Mergansers in this same spot on the river a few weeks before this, and I wondered if it was the same pair, and if they were protecting this strip of the river as their territory. If so, I would consider this to be a relatively poor territory, as it was right in a section of river where what appeared (and smelled) to be a waste-water drainage pipe was flowing into the river, making the water smelly and murky. If this is truly a poor territory, it may be indicative of poor fitness of these Mergansers. I also noticed a Double-crested Cormorant diving for fish in the main pool at the entrance to the park, again in the same location where I had previously spotted a Cormorant. I wondered if this was the same Cormorant, and if it was protecting this territory. If this Cormorant was indeed protecting this territory, I would consider this main pool to be prime territory, as the pool is a popular fishing spot with seemingly good water quality as compared to other areas of the river. I noticed lots of small fish jumping out of the water in this area, further demonstrating this pool's ability to be considered a prime territory. In order to defend a prime territory as such, this Cormorant must have relatively high fitness compared to the other competing birds in the area. The Herring Gulls I observed in the area, if not flying, were in areas along the rocks next to the river where short vegetation was nearby. This small vegetation seems to be preferential for their nesting habitat, and I assume that the birds would not have to fly much further from this general area to find things such as bones, feathers, grasses, and vegetation to build their nests. I also wondered about the nest selection of the Red-tailed Hawk I spotted flying overhead. I assumed it must be nesting in a different area with taller trees, though it may have been in the Salmon Hole area to find materials to build its nest such as pine needles, bark, and twigs.

MINI ACTIVITY: I am unsure of how to add a picture to this journal entry, but I will describe the sounds I heard while standing still and fishing slightly downstream from the main pool. I was fishing on the South side of the river, facing North. The most prominent song I heard during this time was that of a Red-winged Blackbird, which was just across the river from me. This was a loud and clear song, so the quality of the sound was considered to be high. To my East, I was able to hear a Song Sparrow's song coming from the area of the main pool. This song was much quieter, though it was fairly easy to pick out, so I would consider it to be medium quality. I heard two Canada Geese to my Northwest, and a few minutes later in the same direction, I heard (and saw) three American Crows. I also heard what I believed to be a Cardinal, and this song was coming from the Southeast. I would rate the quality of this sound as poor because the song was at a much slower tempo than I normally hear from Cardinals and it was hard to pick out. I heard very vaguely the (Hey Sweetie) song of a Black-capped Chickadee coming from the East, and when I walked back this way to leave, I spotted three of them. I would rate the quality of this sound as medium because although quiet, it was easy to pick out the species.

Posted on April 26, 2021 08:47 PM by tjkeegan