Field Observation 6 - Reproductive Ecology and Evolution

Date: April 21, 2019
Location: Salmon Hole (44.4870° N, 73.1881° W)
Weather: about 70 degrees F, sunny, only a few clouds, slight wind
Habitat: mixed hardwood trees (some maple, birch, cottonwood)
Other: the whole pathway I usually walk down was flooded, the river had a strong current, most of the trees seemed to be budding
Arrived: 11:54 am
Departed: 1:36 pm

Birds Observed:
• American Crow – saw one flying over the Winooski River
• Black-capped Chickadee – heard a few in the trees nearby Riverside Ave
• Blue Jay – I think I heard one because the call sounded like “Cheer” to me, but I haven’t seen or heard any Blue Jays at this site before, so I could be wrong
• Tufted Titmouse – heard one calling for about a minute straight
• White-breasted Nuthatch – heard a few calling
• Northern Cardinal – heard one calling when I first walked by
• Eastern Phoebe – heard one calling nearby the Black-capped Chickadees
• Heard one unidentified bird that had a high-pitched call with 4 of what sounded like the same notes in a row repeated quickly

This past week there had been a lot of rainfall, so when I arrived the pathway that I usually walk down was flooded. The majority of the areas that were accessible by foot were submerged with water. In addition, the river has a strong current so I didn’t see any waterfowl where I was. They might have been further downstream, away from the Winooski Dam.

I mostly just aurally observed behaviors related to mate selection and defense. This included a mix of songs and calls made from individuals of the same species vocalizing back and forth. There were a few times where the Black-capped Chickadees would call loudly at another, which could have been related to territory defense. I didn’t notice any major signs of nest selection and I didn’t really see any nests that appeared to be for a bird. I saw a few places where there were clumps of leaves but thought those were more likely from the squirrels. It was also challenging to visually see behaviors since many of the species that I was hearing today were at the tops of the trees and hard to locate.

Many of the species seemed to be nesting in the more interior parts of the woods. There is a section between the Winooski River and Riverside Ave with a lot of bird activity and trees with clumps of leaves. Along the pathway to the Intervale, there are a lot of snags and trees that have old holes left from woodpeckers that could serve as nest. Many of the smaller Passerine birds that I observed prefer cavities to nest in, and some of the other species prefer built nests in trees or buildings.

One species that prefers cavities includes the Black-capped Chickadee. For example, they can nest in the cavities left by Downy Woodpeckers. Typically, their nests are about 1.5 – 7 m off the ground and they prefer dead or dying trees. Tree species such as birch, aspen, or sugar maple are often chosen for their nest site. One species that nests in along buildings is the Eastern Phoebe. Usually they will set up their nest close the roof, to provide shelter from the elements, about 1 – 5 m from the ground. They avoid damp sites because it increases the chance that the nest will fall and try to pick a site with suitable foraging habitat. A species that likes nesting in shrubs with dense foliage includes the Northern Cardinal. They prefer species such as elm, sugar maple, box elder, honeysuckle, spruce, and pines. The nest is usually constructed within the crook of smaller branches about 1 – 15 feet above the ground. Suitable building materials include leafy material, bark, grass for lining, and small twigs. In some cases, in areas with a lot of human products, paper or plastic is used in nest construction as well.

Sources
• Allaboutbirds.org
• Birds of North America website

Posted on April 21, 2019 10:29 PM by mwolpert