April 19, 2021

Field Journal 6

Date - 04/19/21
Start time - 2:30 pm
End time - 4:00 pm
Location - University of Vermont, Burlington VT
Weather (temperature, wind speed/direction, precipitation) - 60 degrees, 9mph wind S, partly cloudy
Habitat(s) - grass lawn with ornamental oak, sycamore, thornless honeylocust, and Kentucky coffee trees

Today's birding was stationary due to a sprained ankle, so I don't have many observations.

Posted on April 19, 2021 21:26 by hilarygood hilarygood | 2 observations | 0 comments | Leave a comment

April 06, 2021

Field Journal 5

Date - 04/05/21
Start time - 3:09 pm
End time - 4:49 pm
Location - Red Rocks Park, South Burlington, Vermont
Weather (temperature, wind speed/direction, precipitation) - 54 degrees, 15mph wind NNW, sunny
Habitat(s) - white pine, beech, and white birch forest with swampy spots and plenty of underbrush; rocky lakeshore; grassy forest edges along walking trails

My phone died shortly into my birding session, so I saw many more birds than I got to document. I'll list them here before responding to the journal prompt.
Northern Cardinal - 2 individuals, male and female
Turkey Vulture - 1 individual
American Robin - 1 individual
Tufted Titmouse - 2 individuals
White-breasted Nuthatch - 1 individual
American Crow - 1 individual
Gulls? - 2 individuals (couldn't see leg color or beak marking to ID as Herring or Ring-Billed)
Cooper's Hawk? - 1 individual (I think Cooper's and not Sharp-shinned because of its size)
Common Merganser? - 2 individuals (based on white wing patches, rapid wingbeats, and head shape)
Winter Wren? - 1 individual (based on upright tail, all-over brown with slightly lighter underside, faint white eyestripe) also may have been a Hermit Thrush

Migration is physically and energetically taxing, so birds that can survive without migration will stay in the same place over the winter. Migrating or not is determined more by food availability than by temperature; if a bird has enough food, it can keep itself warm. Some American Crows migrate, while others stay all winter. Over winter, crows form large flocks that allow many crows to benefit from one crow's discovery of food. They scavenge and will eat almost anything, so they're able to find enough calories to stay warm.
Downy and Hairy Woodpeckers spend the winter in Vermont. They're able to find insect larvae in trees all winter, and they can hollow out shelters in trees to keep warm at night.
Black-capped Chickadees flock together to help each other find food and keep warm. Birds also grow more insulating down in the winter, and puff up their feathers to keep warm by trapping. Some birds can decrease their body temperature significantly over the winter, entering torpor to conserve energy. Others can keep their featherless feet much colder than their bodies to avoid losing heat.

Common Mergansers are migrants, and they usually make their way north early in spring. Vermont has mergansers year-round, but according to All About Birds, all mergansers migrate. The ones arriving for the spring might be coming from southern Vermont or Massachusetts. Decreasing ice cover on the lake makes it possible for mergansers to find food.
I don't think I found any obligate migrants.

Mini Activity: Most of my birds were year-round residents, but the very rough total mileage of the migrants was 1680 miles!

Posted on April 06, 2021 20:51 by hilarygood hilarygood | 6 observations | 0 comments | Leave a comment

March 22, 2021

Field Journal 4

Date - 03/20/21
Start time - 1:50 pm
End time - 3:20 pm
Location - Mt. Philo, Charlotte, Vermont
Weather (temperature, wind speed/direction, precipitation) - 50°F, 5-10mph wind from SW, sunny
Habitat(s) - moderately dense deciduous forest with beeches, birches, and some cedars at the base; heart-leaved birch forest with large openings towards the top; cedar and pine clusters on rocky outcrops at the summit

The two nuthatches I saw were busy avoiding hikers and birders, so I didn't get to watch them communicate for too long. I heard them calling back and forth with what AllAboutBirds describes as a nasal "yank", which I think is accurate. From what I researched, nuthatches live in pairs year-round, so I probably saw a male and female foraging together. They both flew away from where I spotted them at the same time, which is why I think they were communicating and not just making noise. I didn't get to watch them long enough to read their body language, but I read about nuthatch physical communication. They raise the feathers on their back, spread out their tails, and flick their wings when they're agitated. To communicate that they are giving up a confrontation, they raise their beaks and tails while lowering their wings.

The nuthatches and raven (or crow) had very different plumages. While the corvid was a uniform shiny black, the nuthatches had white bellies and cheeks, gray backs, and a black (male) or gray (female) cap. The corvid's feathers are strengthened by the melanocytes that give them their black color. Black plumage stands out on snow, leaves, and dead tree trunks, so the corvid's feathers aren't serving as camouflage. It's possible that because of their size (raven) or aggression and tendency to flock (crow), the corvid doesn't need to hide to avoid predation.
The nuthatch's dark back and light underside create a kind of camouflage known as counter-shading. While the exact function is debated, counter-shading helps birds to match their background from above and below, and it also breaks up their silhouette from the side. Since nuthatches are much smaller than crows and ravens, they may rely more on camouflage to avoid predation.

The corvid was perched in a dead pine tree when I saw it. This time of year, many mature ravens are building nests and getting ready to raise young. This one could have been taking a break, or it could have been immature and not nesting this year. The nuthatches appeared to be foraging. They could have been looking for fresh food as the forest thaws, or they could have been retrieving seeds and insects cached behind tree bark before winter. Most nuthatches breed in May and June, so it's unlikely that this pair was building a nest yet (and I didn't see them with any materials).

I tried spishing at the nuthatches, but they were already on the move by the time I got around to it. I don't think that's what drove them away, but it certainly didn't attract them.

Posted on March 22, 2021 20:55 by hilarygood hilarygood | 2 observations | 0 comments | Leave a comment

March 08, 2021

Field Journal 3

Date - 03/07/21
Start time - 4:00pm
End time - 5:30 pm
Location - Red Rocks Park, South Burlington, VT
Weather (temperature, wind speed/direction, precipitation) - 25 degrees, no wind, clear skies
Habitat(s) -Eastern white pine forests with deep shade, sparse underbrush; young ironwood and musclewood groves with plenty of sun on rocky outcrops

I had surprisingly bad luck finding birds this time around. Over ninety minutes, I identified one Hairy Woodpecker, saw one hawk fly overhead too fast to photograph, and heard a few scattered chirps. I may have had more luck near the edges of the forest, because a lot of the habitat had thick evergreen cover without much underbrush for shelter or food.
The Hairy Woodpecker foraged the entire time I could observe it. It was up high on a dead deciduous tree pecking holes into the branches. Since food is less plentiful in winter, it makes sense that birds would be spending more of their time looking for it. Hairy woodpeckers primarily eat larvae in wood, but they feed on seeds and berries occasionally. Minus the berries, this one's winter diet is probably pretty similar to its summer diet.
I'm not sure what the woodpecker was doing to stay warm, other than producing heat through activity. Its feathers didn't look fluffed up from far away; the wind was calm and it was already active, so it might not have needed the extra insulation. I poked around a bunch of dead trees, and the forest at Red Rocks had plenty of cavities it could have spent the night in.
Even though I didn't find any birds through it, I had a lot of fun with this week's mini activity. The friends I brought laughed at me for hitting dead trees with sticks, and unfortunately I did not give them a reason to stop by actually finding birds. Most of the cavities I found seemed to be excavated by woodpeckers for food, as they weren't deep enough for nesting or shelter. A few trees had promising cavities, but despite my very polite knocking, no one came out to say hello. Snags are an important source of shelter for birds in winter. Cavities in snags provide respite from wind and snow. Woodpeckers like the one I saw use cavities, as well as other common cavity nesters like chickadees and nuthatches, plus some smaller owls and raptors.

Posted on March 08, 2021 21:38 by hilarygood hilarygood | 2 observations | 0 comments | Leave a comment

February 22, 2021

Field Journal 2

Date - 2/21/2020
Start time - 4:00 p.m.
End time - 5:30 p.m.
Location - Burlington Bay, Burlington, VT
Weather - 25 degrees Fahrenheit, sunny, low wind
Habitats - freshwater lake, city

I got to observe a probable ring-necked duck's flight for around thirty seconds. It took a bit to get off of the water, and it stayed within a few feet of the surface for its entire flight. Its wingbeats were fast and mechanical. The duck's wings were medium-length but very narrow and pointed.
I didn't get any pictures of the gull I observed, so it's not in my observations. Compared to the duck's flight, the gull's was more acrobatic, with slower wingbeats and a higher elevation. Its wings were also narrow, but considerably longer than the duck's.
We discussed the effects of wing-loading and aspect ratio on flying ability in class; the gull and duck provide good examples of how different species optimize their wing shape and size for their lifestyle. Ducks usually fly for short distances and spend most of their time in the water, so they can afford higher wing-loading, and while their high aspect ratio means they need more lift to get off the ground, they can still easily take off from the surface of the water. Gulls have lower wing-loading because they spend more of their time foraging, which means they need to be able to fly without expending much energy. They have longer wings to allow for dynamic soaring, but they still have a higher aspect ratio than, for example, a red-tailed hawk.
The fast, mechanical flapping of a duck's short wings are very characteristic of ducks, so even though I wasn't able to make out the markings on my "ring-necked duck", I could tell it wasn't a gull or a cormorant. The gull was even further away, but their wide wingspan, maneuverability, and combination of soaring and fast wingbeats are pretty distinctive.

Posted on February 22, 2021 21:59 by hilarygood hilarygood | 4 observations | 0 comments | Leave a comment