Field Observation 2: Physiology

I went to Oakledge Park in Burlington, VT on Tues., March 2, 2019. I arrived at about 6:40 AM and the sun was out and the temperature was ~17 degrees Fahrenheit. I went at this hour in hopes birds would be more active as they are fueling up for the day and the sun is coming out and warming up insects in trees perhaps.

The first sighting, to no surprise, was an American Crow. He was perched high in a tree looking as if he was bathing in the rising sun, his black feathers glistening. This black coloring all over the birds body may help to keep the bird warm in colder climates since black absorbs light/heat. There were a couple of other crows that I sighted in the area as well. They seemed to all be calling to each other.

The second sighting was a Northern Cardinal, also perched high in a tree taking in the sun.

Then, I heard knocking on a tree and was able to find that the source of the knocking was a Pileated Woodpecker, easy to sight from afar by his red head. He was flying around between a group of trees, all of which had holes already dug out by him or another woodpecker. He seemed to be looking for insects within the bark as he would peck the tree, then pause and carefully stick his tongue into the dug out bark. There were snags near the patch he was feeding in which were covered by large cavities, perhaps a result of excessive woodpecker activity. Some of these standing dead trees had more oblong rectangular holes rather than circular ones which may be indicators of the woodpecker's winter roost since their nesting holes are usually more oblong.

Next I saw a group of Black-capped Chickadees who were flying around with great speed dodging trees and acting as if they were playing a game of tag. Maybe this chasing game was a way to warm up for them in the early morning after surviving through the cold dark Vermont night. These Chickadees seemed to have some winter weight on them, helping them keep warm. Since Chickadees primarily consume insects, i'm sure that in the winter since insects are not nearly as prevalent they have to rely on seeds and dried fruits that they can scavenge.

Finally, I heard some more knocking among a group of trees. To my surprise, it was not the Pileated Woodpecker, but rather it was a Downy Woodpecker. He also seemed to be feeding. However, he remained within a patch of dense conifers between branches. Since it was a chilly winter morning with some extra wind chill, I assumed that he was attempting to shield himself from the cold wind.

On this property there were patches of conifers that seemed to be more dense, therefore more insulated from rain, snow, and wind. These conifers are most likely the sites where many of these species choose to roost at night. Social species such as the Chickadees and Nuthatches most likely roost in groups to share body heat.

There were many snags throughout Oakledge. There were around seven towards the waterfront, and 5 along the path leading to the bike trail. The ones near the waterfront had a lot more holes from woodpeckers than the ones along the path. I knocked on every snag I passed by however the only extra activity I was able to see from this tapping was one Squirrel that jumped away to another nearby tree. I assume that since it was morning a lot of birds were done roosting and enjoying the risen sun. Maybe later in the day more birds would have risen from these snags upon disturbance. I believe the snags towards the waterfront were occupied by a couple woodpeckers and some chickadees. The snags along the path may have been occupied by some squirrels and songbirds like cardinals and nuthatches.

Overall, these birds are doing their best to stay insulated, and seek out dried seeds or fruits (unless they are a woodpecker) as the ground is frozen and insects are scarce compared to in the spring or summertime. They utilize snags because they are usually hollow in parts and easy for birds to insulate themselves in. Snags are important parts of ecosystems as they provide habitat and shelter for many animals, especially wintering birds.

Publicado el 09 de marzo de 2019 a las 03:39 AM por taylorehwa