toukokuu 8, 2021

Field Journal 8

Date - May 8th, 2021
Time - 11:00am - 12:35pm
Location - Centennial Woods - Burlington, VT
Weather - Overcast skies, 53 degrees F, light wind
Habitat - Mixed deciduous/conifer forest, stream, floodplain

Julkaistu toukokuu 8, 2021 09:39 IP. käyttäjältä gthiggins gthiggins | 10 havaintoa | 0 kommenttia | Jätä kommentti

huhtikuu 24, 2021

Field Journal 7: Reproductive Ecology and Evolution

Date - April 23, 2021
Start time - 12:00
End time - 13:30
Location - Intervale and Riverwalk
Weather - Sunny, 50 degrees, moderate wind
Habitat(s) - Deciduous, floodplain forest, Agriculture, River

I noticed behavior related to reproduction throughout the day. It is clear that birds are in the processes of mate selection, territory establishment, nest building, and egg laying. First, I saw an American Robin on nest. The nest was about 10 feet up in the crotch of a thin deciduous tree (see figure 1: https://docs.google.com/document/d/1ISR4lDfVUAxZtw_siz1_ohjNSSAL2CImqDzYR-pQ2BQ/edit?usp=sharing). The nest was about 5 inches in diameter and deeper than I expected it to be. It was made from thin twigs and even some thin strips of plastic. This nest was located very close to the walking trail and close to the trailhead with people and cars often passing underneath. I was surprised to see a nest so close to all of this commotion. I think this goes to show how comfortable a species like the American Robin has gotten to our human presence and built environment. I wonder if all of the better nesting locations further into the woods were taken, and that's why this robin had to build a nest in a less desirable place.

Further along into the Intervale trail I noticed one particular area where there were a lot of birds singing. Specifically, I noticed a male and female pair of Ruby-crowned Kinglets that were communicating back and forth, singing loudly and frequently in this area, and were using the space. Other birds seemed to often come into this area but would only pass through and wouldn't stay long. It seemed to me that the two Ruby-crowned Kinglets were defending this territory. The area they were defending seemed to have good resources. It had trees of varying size, some with fruit on them and plenty of roosting spots. This suggests that the two birds have good fitness and are able to effectively defend these resources. Birds tend to defend resources when there is an intermediate amount: too many resources, and there is little benefit in defending a territory, but too few resources and a territory that yielded sufficient resources would be too large to defend. There was also a pair of song sparrows that were occupying a jumbled area of twigs and downed trees on the outskirts of the Ruby-crowned Kinglets territory. The kinglet territory is more suited to their habitat preferences as the downed trees and twigs is more suited to the Song Sparrows.

The Sound Map activity was very productive and allowed me to notice a lot of nuance in how the birds in the area are interacting (See figure 2: https://docs.google.com/document/d/1ISR4lDfVUAxZtw_siz1_ohjNSSAL2CImqDzYR-pQ2BQ/edit?usp=sharing)

Julkaistu huhtikuu 24, 2021 08:59 IP. käyttäjältä gthiggins gthiggins | 10 havaintoa | 0 kommenttia | Jätä kommentti

huhtikuu 18, 2021

Field Journal 6

Date - April 18, 2021
Start time - 9:55am
End time - 11:40am
Location - Intervale trails in Burlinton, VT
Weather - overcast and 48 degrees with no wind.
Habitat(s) - Deciduous forest, flood plain/river, agricultural

Some great sightings today - Ornitherapy indeed!

Julkaistu huhtikuu 18, 2021 06:12 IP. käyttäjältä gthiggins gthiggins | 14 havaintoa | 0 kommenttia | Jätä kommentti

huhtikuu 4, 2021

Field Journal 5: Migration

Date: April 3rd, 2021
Weather: Sunny, 45 degrees, windy
Location: Ferry Beach Scarborough, ME
Habitat(s): Coastal beach and dunes, golf course, deciduous forest, estuary

I went to the beach in Maine for this field journal! Very exciting to see some birds in a different habitat. I also saw a harbor seal on the wharf. Of the birds that I saw, House Sparrows, Back-capped Chickadees, Herring Gulls, Mourning Doves, and likely Common Eiders are all residents to the area I was at in Maine. All of these birds other than the common eider are also resident species in Vermont. These resident birds have life histories and physical traits that allow them to live in Maine and Vermont year-round. The Herring Gulls and Common Eiders who often spend time in the water have counter current blood flow in their feet. This allows them to sit in frigid water during the winter without loosing too much heat out of these apteria. House sparrows and Chickadees make regular use of cavities during the winter to shelter them from the cold. They also have thick down feathers which trap heat close to the bird. Migration takes lots of energy so there are advantages to staying in the same place year round. Species that don't migrate must be able to survive the cold and find enough food during these winter months.

On the other hand, Red-winged Blackbirds, Eastern Phoebes, and Great Egrets migrate to this area each year. Red-winged Blackbirds can be considered facultative migrants that tend to migrate only if winter conditions are particularly harsh. The areas that they are residents year round are very close to Vermont and even creep into parts of Southern Vermont. Eastern Phoebes are short distance migrants that migrate from Vermont to mid-latitude United States and into Central America. In Vermont they are obligate migrants because of the harsh winters. The Eastern Phoebe I saw may have been migrating from Florida, Georgia, or the Carolinas. Eastern Phoebes are flycatchers. So, in order to do well in Vermont, they need the insect populations here to blossom in the Spring before they make their migration back to their breeding grounds here. Species that migrate back to Burlington early have the advantages of setting up territories early and claiming nesting sites here earlier than other birds. This could be a huge advantage if they know where the best resources will be. With that being said, it is hard to predict this, so they might not pick the best areas.

Eastern phoebe (Central Florida -> Scarborough, Maine) 1223 miles
Great egret (Coastal North Carolina -> Scarborough, Maine) 681 miles
Red wing black bird (West Virginia -> Scarborough, Maine) 495 miles

These migrant species traveled a total of ~2399 miles to get from their wintering grounds to where I saw them in Scarborough Maine!

Julkaistu huhtikuu 4, 2021 09:32 IP. käyttäjältä gthiggins gthiggins | 8 havaintoa | 0 kommenttia | Jätä kommentti

maaliskuu 22, 2021

Field Journal 4: Social Behavior and Phenology

Date: 03/21/21
Location: Intervale, Burlington VT
Weather: Sunny, clear skies, 45 degrees
Habitats: Agricultural fields, Shrubby forest edge, river corridor, floodplain forest.

The birds were out in full force today! Many migrants coming back for the Spring. Birds are social species and I was able to witness some interactions today. The most dynamic interaction I saw was between two Hairy Woodpeckers. One woodpecker was probing on a downed tree, the other one approached the same tree only to be chased off. The first communicated its desire for the second one to leave by loudly vocalizing - rapid, harsh notes - and by flapping its wings at the other bird. This is an example of intraspecific competition and territoriality. It may be more energetically beneficial for the woodpecker to expend energy defending a territory if there is good food there. I observed many Black-capped Chickadees, White-breasted Nuthatches and Tufted Titmice that were all occupying the same area. They seemed to tolerate and even be drawn into the same area. I also observed three chickadees that seemed to be chasing each other. This could be a breeding/courting activity. The main way that birds seem to communicate is through their vocalizations. They vocalize to attract mates and establish territory. I reason that this group of birds was singing to mate rather than defending territory because there were many birds i the same area. One individual bird I focused on was the feeding Hairy Woodpecker. It was tapping into the bark of a downed tree. This feeding behavior fits into the context of its circannual rhythm because food is becoming increasingly more abundant. Hairy Woodpeckers feed on insects within trees. These insects' populations blossom in the spring and sustain the woodpeckers. This influx of food allows the Hairy Woodpeckers to breed (a very high energy activity) at a time when there is plenty of food.

The Mourning Doves that I saw were overall tan with black spots on their wings. Their plumage nearly perfectly matched their surroundings. I observed them feeding in an area of twigs and underbrush. Their plumage pattern likely evolved to camouflage them in these environments. On the other hand, the male Northern Cardinals that I saw were easily spotted with their bright red plumage. Their plumage supports a different evolutionary purpose: attracting mates. Male cardinals that have brighter and better looking plumages are more likely to be sexually selected by a female and will pass on its genetics. This benefit must outweigh it being easily sighted by predators.

I experimented with spishing among two different foraging flocks. The first group had Black-capped Chickadees, a Tufted Titmouse, and House Sparrow in the area. When I spished, it seemed as though the birds stopped singing and listened, and then began their calls again with even more energy. The second group had Black-capped Chickadees and White-breasted Nuthatches. When I spished here, I noticed a few of the the birds move closer - in fact, two of the chickadees came to a tree right above my head! They seemed very curious.

Julkaistu maaliskuu 22, 2021 03:36 AP. käyttäjältä gthiggins gthiggins | 12 havaintoa | 0 kommenttia | Jätä kommentti

maaliskuu 7, 2021

Field Journal 3: Ecological Physiology

Date: March 6th, 2021
Time: 12:55pm - 2:20pm
Location: Notch road, Jeffersonville, VT (Route 108).
-> I walked 1.22 miles from the Smuggler's Notch Upper parking lot to the Sterling Pond Trail Head
(then back along the same route).
Weather: 20 degrees, cloudy, windy
Habitats: Mixed deciduous forest with lots of snags.
Elevation: 1,670 ft at the parking lot; 2,108 ft at the trail head.

I only saw 6 individual birds along this 2.44 mile stretch of the notch road. Both the two crows and two out of the four chickadees I saw were very close to the parking lot where I started. In fact, I observed the crow swooping down onto the parking lot to grab what looked like a piece of bread from the ground. Two of the chickadees were near/feeding from a bird feeder set up by one of the Smuggler's Notch employees. These birds seem to be relying heavily on food provided by humans during what must be a difficult time to find food. I assume that this late in the winter many birds are having trouble finding food and their fat stores are running low. Relying on humans/more urban places/bird feeders for food may be one strategy to get enough food through this part of the winter. I expected to see more birds than I actually observed on the Notch Road. There could be a few reasons for this. It was the middle of the afternoon when birds are less active, it was a very cold and windy day, and early migrants are not coming to the harsher/cold/higher elevation areas around the mountains. I wonder if most early migrants tend to go to warmer areas where they can find food. Maybe this stretch of the Notch Road only has birds that have overwintered there now (like Black-capped Chickadees and American Crows), but as the weather warms, more birds will migrate the that area. The "notch" between Mt. Mansfield and Sterling Mountain may provide some shelter compared to the peaks of these mountains.

Birds have a number of strategies to survive in cold weather. Down feathers are an important part of retaining warmth through the winter. Another important strategy to survive cold weather is taking shelter out of the cold and wind inside of snags and tree cavities. This is one behavioral strategy that allows birds to live in cold areas. They likely spend less time moving/out in the cold during the winter to retain energy. Snags/tree cavities are a huge asset to birds in cold climates and often the number of tree cavities is a habitat requirement that limits the number of birds that can live in an area. Overwintering birds like Black-capped Chickadees, Tufted Titmice, nuthatches, Brown Creepers, and others will use tree cavities. This stretch of the Notch road boasted numerous snags. In fact just along the sides of the road, I noticed at least one snag almost every 20 feet!

(See this link to view a map of snags: https://docs.google.com/document/d/1QdFpXojDMlfMKww9fr8GyfPKhlbdPVMgp7gUOWLWBKk/edit?usp=sharing ).
Note: I only recorded snags that were within ~30 feet of the road.

This tells me that this area could be a good place for the species to live who need tree cavities during the winter. I noticed some snags with longer holes likely created by Pileated Woodpeckers and other smaller cavities created by downy and hairy woodpeckers. The larger trees seemed to have larger holes in them. None of the snags that I tapped on had any birds come out.

Julkaistu maaliskuu 7, 2021 09:06 IP. käyttäjältä gthiggins gthiggins | 2 havaintoa | 0 kommenttia | Jätä kommentti

helmikuu 21, 2021

Field Journal 2: Flight Physiology

Date: 02/21/2021
Start Time: 9:09am. End Time: 10:40am
Location: Davis Center circle -> Redstone -> Along S. Prospect St.
Weather: Sunny, 20 degrees F, 5mph NW wind
Habitats: Suburban environment, mix of buildings and open spaces with patches of trees. Bird Feeders also present.

View field sketch (w/ field marks) of a House Sparrow via this link: https://docs.google.com/document/d/1X-JeKqRrbxb4XKh31Tgi8L8e7ASYbtaKQ_bh66fqFfQ/edit?usp=sharing

Bird physiology directly impacts flight behavior and mechanics. Wing shape is the main determinant of flight capabilities. Most often, bird wing shape corresponds to their habitat and niche. On an evolutionary time scale, birds wing shape was selected to best suite their habitat. For example, the Common Redpolls I observed today have elliptical wings. They are the best wing shape for maneuvering through their habitat: thicket, branches, and trees. Today, I observed these birds weaving in and out of branches in a cedar tree, between planted shrubs, and the sides of houses. They flapped their wings at a high rate and made lots of small turns and adjustments while in flight. They were never in the air for very long until landing again. This could be because they were comfortable with cover and food (nearby bird feeders) in the area I saw them today. They are able to move quickly and nimbly through this landscape in part because of their elliptical wings.
This flight pattern was a sharp contrast to the Herring Gulls I saw flying overhead today. These gulls were soaring ~40 ft in the air and rarely flapping their wings. It is clear to see that they could fly long distances without expending much energy. This is thanks to their long and narrow wings, with pointed wing tips. These high aspect ratio wings lower drag and increase lift. They suite the habitat and niche of Herring Gulls because they fly long distances in wide open spaces (with lots of wind). Flight pattern could be a great hint to identify birds. I know that a soaring, smooth flight pattern may belong to a herring gull. Or, if I see a highly maneuverable bird moving between shrubs with fast wing beats, this could clue me in that it is a Common Redpoll.

Julkaistu helmikuu 21, 2021 09:48 IP. käyttäjältä gthiggins gthiggins | 10 havaintoa | 0 kommenttia | Jätä kommentti

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