April 27, 2021

Field Journal 7

Sunday April 25th I started birding at 6:53pm it was partly cloudy, had rained earlier in the day and was about 45 F. I was at Ethan Allen Homestead so the habitat was a mixture of denser vegetation, riparian areas, and open fields.

At the beginning of birding there were lots of audio displays from the birds that seemed to correlate more with an establishment of territory because of the added winged and head displays that looked more dominant to me. However, there were also some calls and responses which I think indicate more of a mate selection.

When I first started birding I was standing on the edge of a field of cattails with a few trees and bushes that were dispersed inside the patch of cattails. I saw 6 male Red-winged Blackbirds that were distributed uniformly throughout the patch, usually in a tree or bush. In particular, there was one male who stayed the longest in this patch, starting in a tall bush and after about 10 minutes moving to a different tree in the patch while other males were less persistent. I think that this male was potentially more fit than others because of its persistence and it having the most dominating call compared to the others, also because it didn't look like any other male was challenging it directly. This male would also extend its wings and tilt it's head up when it was calling. After observing this I believe this was an audio and visual display related to territory/nest selection, also because there appeared to be females in the cattails gathering nesting materials. I believe that this section of dense vegetation is where the red-winged blackbirds are nesting because they build nests lower among shrubs.

I saw some other nests in older trees that were higher up and looked like robins nests because of how dense the materials were woven together. Therefore, I think the robins are more likely to be nesting in the forested areas of the property while the red-winged blackbirds are more likely to nest in dense sections of cattails. These habitat requirements are different because one bird nests lower down while the other nests higher up, furthermore, it seems that the American Robin relies on physical distance from potential predators while the red-winged blackbird relies on coverage and being camouflaged. I also saw two a very small nests that were in lower bushes among small dense branches located near the river. I don't know what kind of bird made this nest, but it would seem that its habitat requirements maybe also rely more on being covered and blending in, especially if they nest when leaves and flowers have bloomed.

It looked like the robins were gathering more of straw-like almost stringy material while the red-winged blackbirds looked like they were gathering more fibrous materials. In order to find the straw/stringy material I think that the robins would have to go places were there have been ruminants of tall grass and other plants that have been buried under the snow all winter. Thus closer to fields and forested areas would be ideal.

Posted on April 27, 2021 02:29 by maliabertelsen maliabertelsen | 6 observations | 0 comments | Leave a comment

April 19, 2021

Field Journal 6

On April 18, 2021 I went to the Richmond park in Richmond, VT and sat by the Winooski River starting at 4:00pm and walked along the banks until 5:30. It was clear and sunny and was about 50 F. This was mostly a riparian area because it was all along a river bank.

Posted on April 19, 2021 20:47 by maliabertelsen maliabertelsen | 8 observations | 0 comments | Leave a comment

April 05, 2021

Field Journal 5

I started birding at 8:00am, it was sunny but a little windy with a temperature of 39F. I walked down the street to Pomeroy Park and stayed there sitting still in various parts of the park, so the habitat was urban/urban green space with some trees a clearing and some bushes. I think this habitat is why it was more difficult for me to take pictures of the birds, they mostly stayed in the trees or bushes or were flying, and if they were on the ground it was not for very long. This could be because early April is before breeding season so each of these birds is considering their energy costs and which will be the most profitable for them to invest in.

The year round residents that I observed were the House Sparrow, Ring-billed Gull, Tufted Titmouse, Blue Jay, Northern Cardinal, and European Starling. I think they forgo migration because their diets are not solely reliant on insects, instead they are able to forage and eat various berries and other plants that are available year round. The physiological and behavioral adaptations that allow them to survive year round in Vermont include being able to poof themselves so there is an increased amount of feathers around them to trap body heat. Furthermore by being cavity nesters such as Tufted Titmice, they are able to access the best nesting sights which increases their reproductive success. Ring-billed gulls are also able to conserve body heat through the winter by covering apteria parts of their body this includes sitting on their legs or standing on one leg and tucking the other. Furthermore following Burgmann's rule that body size increases with latitude these birds bodies may be more suited for the thermoregulation necessary for the winter opposed to smaller migratory birds such as hummingbirds. The cardinals, house sparrows, and blue jays especially appeared to be interacting with one another perhaps to have an advantageous edge on other species for nesting availability and resources.

The facultative resident I observed was the American Robin. They are likely coming from a place that is southern but still relatively close to Vermont, such as North Carolina. Although in milder winters it is possible that robins will stay year round. The American Robin is making its way back to Vermont for breeding because as the weather is warming up more food is available and the habitat is becoming ideal for nesting. This includes new vegetation which better conceals nests and there being more available nesting material. The robins I saw were all on the ground looking for food which could indicate fueling up after migration and before breeding.

The obligate migrant I saw was a Turkey Vulture. It could be advantageous to arrive in Burlington in early April in order to secure optimal territory for feeding then breeding. Since migration is one of the highest energy cost events that a bird will experience it will want to space it out from breeding which is the next high energy cost event. By arriving early, the obligate migrants allow themselves time to feed and establish territory from other birds which gives it a greater advantage during breeding. Since Turkey Vultures can winter as far south as Central America, their timing of migrating to Vermont is reactive to the amount of daylight they are experiencing, as such they can have a disadvantage of not knowing the climate of where they are migrating to. This could mean unexpected spring snow storms (like what we had last week), this could harm their ability to forage for food or have adequate shelter and overall ends up being more energy costly after migration.

Mini activity: The House Sparrow, Ring-billed Gull, Tufted Titmouse, Blue Jay, Northern Cardinal, and European Starling would have a wintering rage that stays within the area that I observed them. A robin traveling from Durham, NC to Burlington, VT would cover a total distance flying of 1,057.79 km. A Turkey Vulture Traveling from Miami, FL to Burlington VT would cover a total flying distance of 2,168.34 km.

Posted on April 05, 2021 18:50 by maliabertelsen maliabertelsen | 8 observations | 0 comments | Leave a comment

March 22, 2021

Field Journal 4

Sunday March 21, 2021 at 9:32am I started birding along the bike path. It was about 40 F very sunny with clear quiet skies. I was observing the edge of a freshwater lake and the land that created an edge against it. This habitat consisted of cottonwoods, trees that produced berries, tall clumps of grass, and other shrubs. However, this was also along the bike path so there was a decent amount of human activity including the skate park, bikers, joggers, and people roller blading.

When I first started birding I saw six ring-billed gulls sitting on the ice that had frozen over the lake. They were in three groups of two with a good amount of distance between the groups. In two of the groups, both birds stayed close to one another, in the other group one of the birds began wondering across the ice while the other gull it was initially with stayed put. It seemed to be wondering and eating something off of the ice. I stayed there for a while and for the most part the birds were just huddled closer together. However, at 9:47, in one of the pairs a gull turned to the other and began squawking and bobbing its head up and down at the other. This seemed most similar to a young bird wanting to be fed by a parent, although they seemed to be about the same age. During this time I also saw a flock of at least 12 geese flying over. They were honking and reshaping their V flight pattern, maybe the honking was key to maintaining the V flight pattern. At 9:49 I noticed five rock pigeons walking at the base of the platform in the rocks. They seemed to be gathering small sticks and other materials before flying up below the deck. It didn't look like they were helping or hindering each other, just all doing the same task. 9:51 a crow flew overhead. At 9:52 I followed the sound of a northern cardinal and found it higher up in a tree. I also noticed that there was a call and response between it and another cardinal, I think it was either attracting a mate or establishing territory. At 10:09 I saw three European starlings flying by, I think it might have been two males possibly pursuing the same female. 10:15 I noticed a Cedar Waxwing in a tree eating berries and eventually noticed three more with it. The birds were each involved in their own task of eating the berries but I think the presence of at least one of them attracted more cedar waxwings. I tried making the "shppsh" noise and I think it attracted more cedar waxwings over, because then I counted a total of 9. I think this could be the case because it could be an encouraging sound of safety or food maybe? It is possible that this sounds like coaxing calls of other birds? 10:25 I saw a robin walking near mud, potentially looking for insects to eat. 10:26 I heard a bunch of blue jays calling and one that flew towards the sound, I think it is possible that this was attracting more blue jays since I saw one fly towards the sound rather than distancing which could indicate establishing territory. The At 10:31 I also observed a male and female cardinal on a telephone wire. The male was making calls and and slowly moving closer to the female before she eventually flew away and he pursued. 10:42 I saw a merganser swimming relatively close to shore where the ice had melted and by the shore I saw two pairs of a male and female mallard. They were dabbling and eating food from the mud. The merganser seemed to just be treading water.

The ring-billed gulls are covered with mostly white, grey, and black feathers while the male cardinal is covered in red feathers. The gull benefits from these melanin colors as they increase the structural integrity of the wings, especially the black feathers at the tips of the wings that I think would face the most friction against water. The Cardinal contrastingly benefits from carotenoid colors because these pigments increase with a rich diet like berries. Therefore, when a male cardinal has an impressive plumage it indicates that that male is healthy and adequate at being able to survive.

The first Cedar waxwing that I saw was intent on continuing to eat the berries in the tree. While these birds can live in Vermont year round, this could work with the circannual rhythm with when birds would be traveling north. Due to migration being a high cost activity, feeding can be key to maintaining energy. It also makes sense that this bird was feeding and active at this time since it was about 10:00am and the sun had been up for a few hours indicating that it was time to be awake and active.

Posted on March 22, 2021 20:33 by maliabertelsen maliabertelsen | 12 observations | 0 comments | Leave a comment

March 09, 2021

Field Journal 3

We started birding Sunday March 7th at 12:15pm at when we got The Intervale. The temperature was mid 20s and it was a clear sunny afternoon with blue skies! We saw a total of 7 different species and saw evidence or heard calls of many more birds. Our excursion began in more dense woody areas with lots of snags, came up to the edge of the Winooski river, then opened up into a field surrounded by trees. We ended a little before 1:40pm.

First we saw 8 robins on a staghorn sumac eating the berries, which my friend Kyle, who is a plant biology major, told me was a winter snack for birds. These robins were moving quickly between the berries, occasionally staying longer on certain berries. As we walked through the woody vegetation and I was examining the snags along the way I saw a stump that was hallowed out at the bottom when I walked around to the other side I saw an owl pellet stuck in the stump! You could clearly see the bones of small rodents left in it. As we came up to the edge of the river I was feeling hopeful that we would see mergansers, instead we saw a crow calling and flying in a linear path before veering to a tree to perch in and another flew by calling. We saw another crow later in the walk but I am not quite convinced that it was a different one.

Further along we saw a small group of 3 white-breasted nuthatches bobbing around what we think was a boxelder tree. It looked like they were poking at the bark. We saw three smaller birds with white and black wings fly to a silver maple next to them and the nuthatches joined. We followed the path into a narrow woody area with fields on either side. Here we saw 8 black-capped chickadees and four white-breasted nuthatches all around the ground and by snags. There was also a male northern cardinal that was perched high in a tree giving its call over and over again. This makes me think that it was looking to attract a potential mate. We kept walking then heard forceful tapping and saw wood shavings falling behind a fallen tree, we carefully and quietly walked around and saw this massive pileated woodpecker going to town on this log. As we came around into the field after we saw four turkey vultures fly over multiple times as we walked away. That field seemed like an ideal place to hunt as it is an edge between dense vegetation and openness. That edge region was actually where we observed the greatest species richness.

Most of the birds we saw were expending their energy feeding off of the habitat around them, mostly foraging and the turkey vultures hunting. I think these foraging birds diets might be more plant based right now as options of insects are currently low compared to the warmer months? I also think it is possible that the birds were more active during our observation time on a sunny afternoon because that could provide better opportunities for hunting, finding food, and attracting mates. I would guess that the smaller birds would overnight in mid levels of dense vegetation so they are out of harms way of smaller predators on the ground and sheltered from larger birds of prey from above.

There was a plethora of snags so there were too many to accurately keep count, but I would say that on average there was at least one snag next to the trail and in the distance. The snags that were slanted over seemed to have the most signs of activity, specifically from woodpeckers that would come and eat the insects living inside. I didn't notice much from rapping a stick on the snag except for when they were exceptionally hallow. There was lots of mulch around the base of these snags and occasionally some green leaves popping up. This makes me think that the snags might offer some more desirable food sources.

Posted on March 09, 2021 04:46 by maliabertelsen maliabertelsen | 11 observations | 0 comments | Leave a comment

February 22, 2021

Field Journal 2 (2/22)

My roommate and I arrived at Mt. Philo State Park at 3:14, it was a clear blue bird day, about 28 F with a slight breeze. Majority of the area we were hiking through was dense deciduous vegetation with a solid layer of snow on the ground. The parking lot was full and walking up to the trail we saw a lot of people sledding, later we also saw lots of snowmobiles going up and down the roads, this could be why we didn't see many birds.

At 3:30 we saw two crows fly over, first one and then the other. We were able to identify them as crows due to their black feathers and rounded rather than diamond shaped tale feathers, that would otherwise be indicative of a raven. When they flew over this first time their flight pattern seemed continuous spending equal times flapping their wings and gliding. The second time they flew over I heard them before I saw them, with a consistent whooshing sound one crow flew overhead and then the other one followed with something in its beak. Maybe this was a pair that is building a nest?

At about 3:50 as we were getting up to the tree line I saw five crows flying together in what looked like a line from my planar perspective. They appeared to be mostly gliding making me think that maybe they were playing in the air? Due to the gliding nature I observed in the birds while they were flying, I think it would make the most sense to classify their wings as passive soaring. I think these wings give the crow greater ability in hunting as it increases observation which is key in dense vegetation like Mt. Philo.

Unfortunately as I didn't see any song birds so I was unable to fill in my drawing.

Posted on February 22, 2021 19:43 by maliabertelsen maliabertelsen | 0 comments | Leave a comment

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