natalielaible's Journal

On February 22nd around 3pm, I went on a bird walk around UVM campus with TA’s Rachel and Danielle. It was a cold, winter day with light wind. We saw some flocks of European Starling above Jeffords and American Robins perched in trees. Songs and calls I heard during the bird walk included Tufted Titmouse, American Robin, White-breasted Nuthatch, and Black-capped Chickadee. I also was able to get somewhat close-up to a Black-capped Chickadee on the sidewalk on South Prospect Street before it flew away.

European Starlings keep warm in the winter with various types of regulation. This species of bird does not migrate, so they must be able to increase their metabolism during winter months to keep warm. These birds are very good at warming themselves up, and have higher metabolic rates than other species their size. They also may puff up their feathers to retain heat, which is an example of a behavioral temperature regulation. I saw some of the flocks stop to perch on top of Jeffords or on the ground, most likely to forage for food and rest from flight, which is extremely energetically expensive. They feed in flocks, and may help other individuals find food, especially juveniles who may need more help. European Starlings feed on mostly insects and other invertebrates, and also eat seeds, fruit, and garbage. Their diet may change during the seasons; for example, insects will be less available during the colder months. They roost in flocks, which most likely helps them retain body heat due to being in close contact with each other, similar to huddling.

We learned in class that Black-capped Chickadees undergo facultative hypothermia during the winter to retain body heat. They lower their body temperature by 6 degrees Celsius at night when they need to save energy. This species’ diet consists of mostly seeds, berries, and insects. In the spring, summer, and fall, Black-Capped Chickadees eat animals as 80-90% of their diet. At feeders, they eat seeds, peanuts, mealworms, etc. They tend to nest in small cavities, and sleep in thickets, dense shrubs, and tree cavities. In order to have a steady food supply for winter, they hoard and hide seeds in small places to save for later.

During the walk on South Prospect Street/Redstone Campus, I noticed two snags with crevices that could be inhabited by birds. One of the holes was very tall and skinny, and one was very small. I see the large tree with the tall crevice everyday during my walk to class, and in the past I had seen a woodpecker on this tree- most likely a Pileated Woodpecker. There are probably more snags in Centennial Woods than on campus because there's many more trees, and more birds in general.

Snags are important because they have many holes and cavities for birds to take advantage of. Woodpeckers, chickadees, nuthatches, owls, and so many other birds use cavities in snags as hiding spots, safety, or to store food for later. Woodpeckers peck at snags bark to find sources of food such as insects and larvae. Snags provide habitat, places for birds to keep their nests, and branches for them to perch on. They can also be used as song posts to attract mates and label territories. Without snags, so many different species of birds would be negatively affected.

I went on a bird walk by myself on Thursday, March 22nd around UVM Redstone Campus. It was a bright, sunny day and about 33 degrees Fahrenheit. The bird species I observed included American Robin, Mourning Dove, American Crow, Northern Cardinal, and Black-capped Chickadee.

Around 12pm I heard a Mourning Dove outside my window at Redstone Apartments and recorded it. I went outside to get a picture, but it flew high onto the roof before I could get a good shot. While it was hiding from me on the roof, I could see its head and identify its skinny, down-curved bill. During its flight to the roof, I observed its body colors. Its underside and head are a creamy, light brown color while the retrices and remiges are a light gray. Their overall pale color helps them blend in with tree trunks, snags, and other neutral tone habitats. They also have dark gray spots on their backside, which aids in camouflage as well. I captured a good audio of the song (cooooOOOOO-woo-woo-woo), which is produced by the male in order to attract mates. It is almost always uttered by the male and not the female. It is also interesting to note that most Mourning Doves mate for life, so once they do find a companion, they remain loyal to them.

After encountering the Mourning Dove, I walked down South Prospect Street and came across a small group of American Crows foraging on a lawn. American Crows are entirely black with shiny feathers. The color comes from melanins they produce themselves. High concentrations of melanins in feathers prevents significant wear and tear and allow birds to molt less frequently. This allows them to save energy for other expensive processes such as flight and keeping warm during the winter. American Crows make loud caws to communicate with other crows, as they are extremely social birds. Calling is important because being in groups most likely increases their ability to find food, especially in the winter.

On the other side of the road in a far tree, I heard a Northern Cardinal. Its bright red plumage revealed its location to me, although it pretty far away. Cardinals get their pigments from carotenoids, which come directly from their diet. Unlike the American Crow and the Mourning Dove, they are very vibrant in color. Males use their bright red feathers to attract mates; the more vibrant the color, the more likely they are to find a female companion. The males call in order to find a mate, which is important for its reproductive success, and therefore a good call as well as plumage color are evolutionary advantages.

I came across a tree closer to central campus, in which about three Black-capped Chickadees were perched and calling. I made some “pish” calls to attract their attention and see how they would react. Most of them flew away to another tree and started calling again. Pishing is an effective birding tool since it is a sound that humans typically do not make, and sounds generally like a bird. It is similar to the scold calls of chickadees. Scold calls are a form of mobbing behavior in order to attract more birds to determine the threat level of a predator.

Sources used:
https://en.wikipedia.org/wiki/Pish
http://www.birdsandblooms.com/blog/10-surprising-facts-about-mourning-doves/