Field journal 7

Field journal 7: Reproductive Ecology and Evolution
April 26, 2021
Start time: 7:48
End time: 9:23
Location: Red Rocks Park, Burlington, VT
Weather: 36 degrees F, 95% cloud cover, NW wind at 16 mph
Habitats: Manages old and young growth forests, neighboring Lake Champlain

Numerous behaviors are being exhibited by birds in regards to breeding season at this time. In terms of visual behaviors, male/female pairs are seen interacting, individuals are sitting still on nesting sites, and aggressive/selective behaviors are exhibited in regards to mate selection and territory defense. For example, male Mallards were observed shaking their heads and flinging them up and down in the presence of a female. This behavior may be related to mate selection by the female. In terms of auditory cues, species have become either aggressive towards other individuals for defense of resources, or exhibit specific vocalizations for attracting a mate. For example, Black-capped Chickadees may be defending their territory with vocalizations that consist of high pitched chirps followed by lower “dees.”

Ideal nesting habitat often varies from species to species. In the location I visited, ideal locations include tree cavities, branches, and shoreline. For some species of passerines and small songbirds, building a nest on top of a tree branch or similar elevated structure is most ideal for them. An example of this would be the American Robin, who creates a very distinct and rather obvious nest filed with bright blue eggs. Their nests could be observed in hemlock or cedar trees in this area that are able to provide year-long foliage as nest protection. Mallards, who are very well camouflaged within vegetation, prefer to nest on the ground near bodies of water. A Mallard nest was observed on land within some reeds near a shallow part of the lake. This allows them to use camouflage to protect themselves and their nest from predators, while being close to food resources and water where chicks will eventually develop. Common Goldeneyes are an example of a species who utilizes snag tree cavities for nesting. This nest site allows them to save energy by using holes remade by piloted woodpeckers, and it provides their nest with great protection from predators and weather conditions until their chicks hatch and are ready to fend for themselves.

I was able to observe a variety of behaviors from some Black-capped Chickadees, as mentioned above, that appeared to be an individual defending a territory through vocalizations. This area of land seemed to be a good territory, a location with lots of cover in bushes and evergreens, pinecones and vegetation for food sources, and water nearby. This spot seemed a bit more ideal than other locations nearby. Because this territory seemed ideal, and the individual was defending it, this may indicate higher fitness for this bird. This is due to its ability to find and properly defend a prime territory against other, less fit, members of its species.

During my observations, I was fortunate enough to observe a male and female pair of Blue Jays building a nest. They chose a spot on a hemlock branch close to the base trunk of the tree for stability and protection. When building this nest, both adults took turns bringing back different materials, primarily small thin sticks. Each bird would fly no more than a dozen yards away in search of materials, where they often scavenged on the ground or picked dead twigs off of nearby cedar trees. This material may be helpful in building a strong structure, but leaves, down, moss, and grasses may be used as good insulation in the nest.

Mini Activity:

https://drive.google.com/file/d/15PKl1XHDq8SpuDtvEXee31p5EeFQKW7W/view?usp=sharing

Posted on April 26, 2021 08:42 PM by acshiers