Journal archives for March 2020

March 06, 2020

Field Journal Post 2: Ecological Physiology

My observation began at 12:30 and ended at 2:30 pm on Tuesday (3/3). It was conducted between Maple Street and Summit Street and also at the Burlington Parks Conservation Office on North Avenue. This was done in order to focus on the birds of the city of Burlington, Vermont. The weather was one of the warmest days of the year and it was quite sunny with some clouds rolling in toward the end of the excursion. It was almost entirely urban habitat and street trees with the exception of the Conservation Office which was a cliffside stand of Eastern cottonwood trees.
Starting on Maple Street I saw the general city birds such as House Sparrows, Chickadees, Mourning Doves, a Northern Cardinal, and House Finches. I identified all by their call and sight. But, after I biked over to the Conservation Office where it was a bit more forested I saw a Downy Woodpecker, White-breasted Nuthatch, and a Tufted Titmouse. In the forested areas, the White-breasted Nuthatch was identified also by its movements up and down the limbs of the trees looking in the bark for something to eat.
Almost all of the birds that I identified and observed during this excursion were doing something to maintain their body temperatures. For example, the Mourning Doves clearly had their feathers fluffed up in order to keep warm air close to their bodies. They were staying very still on the roof of a house. Another strategy is to find cover, this is exactly what the House Sparrows were doing huddled closely together in a bush. They could have also been feeding in this bush while staying warm and socially active and engaged with each other.
Other birds focused primarily on feeding. The House Finches were actively eating fruits out of trees that they were flying between and they were almost constantly moving and calling. This was also the case for the White-breasted Nuthatch and the Downy Woodpecker. The Nuthatch was working its way up and down tree trunks looking for insects in the cracks of the deep bark on the Eastern cottonwoods. The Woodpecker was focusing more on the dead and dying branches in search of insects hidden inside.
In the winter their diets most likely stray further away from fresh berries and new seeds in favor of smaller more hearty insects and older fruits still left on trees. I would assume that many insectivores have relatively consistent diets throughout the seasons though. In terms of overnight habitats, the city-dwelling birds most likely use the infrastructure and planted trees to take cover from the environment. If they were further out denser shrubs, evergreens, or even tree cavities could also be used as cover from the harsh winter conditions.

Posted on March 06, 2020 20:15 by lukebeeson lukebeeson | 7 observations | 0 comments | Leave a comment

March 25, 2020

Field Journal Post 3: Social Behavior and Phenology

This week I did my bird walk in the Cheslin Preserve in Embreeville, Pennsylvania. This is an extensive grassland area with a forested plot around the meadows. Today it was about 50 degrees and partly cloudy. The day before it had rained quite heavily all day and the ground was still quite wet.
I started walking through the meadows and saw numerous grassland birds including Horned Larks, Eastern Bluebirds, and Tree Swallows. I then went into a woodlot and saw many more generalist and forest species. Here, I was able to notice both species and behavioral changes. These changes were obviously linked to the forested area and sub-habitats found within the woodlot.
In terms of communication, I saw a fair amount of direct inter-species communication between the Eastern Bluebirds and Tree Swallows as they dove at each other in competition for the few bird boxes along the meadows. This was a much more obvious communication than others. They were calling and diving, making their communication between the species abundantly clear. These two birds have relatively similar coloration as well. Both are colored with structural pigments that produce two different shades of blue. These colors are also much brighter on the males of each species, indicating that there is some sort of mating aspect to their coloration. There may also be an evolutionary advantage for these aerial insectivores to have white bellies and blue backs and wings.
I chose to focus on one male Northern Cardinal. It was perched on a branch mid-way up a tree calling out and looking around quite alert. This mating or territory call most likely greatly influences the circadian rhythm of the Cardinal because it dictates how the bird spends much of his day. In terms of circannual rhythm, the mating season is a very significant part of the year that the bird spends much of his time and energy on when it is occurring.

Posted on March 25, 2020 00:35 by lukebeeson lukebeeson | 14 observations | 0 comments | Leave a comment