Mia Kosel - 4
I went to Ethan Allen Homestead Park area on April 7th, 2019 around 5pm for this birding trip. The weather was slightly overcast and about 50 degrees. This field observation prompt was all about migration so I kept that in mind when I was out looking for birds. This is an exciting time of the year because the migratory birds are starting to return to northern Vermont. I was hoping to see some bird species that recently migrated back.
I first spotted an American Robin by the homestead area before I headed into the more forested area. The American Robin was picking around at the dirt, most likely looking for food. American Robins are year-round residents here so this bird likely has been around this area all winter. I would think that the ground not being frozen would benefit the American Robin as it can search for insects and such in the dirt. Throughout the winter, it was probably more difficult for the American Robins to find food and would have to rely on a lot of berries to keep their caloric intake up. I also noticed when comparing the American Robin to ones I saw months ago, this one was more active and not puffed up. I know that birds have several strategies for keeping warm and surviving in the winter months. One strategy is fluffing up to minimize heat loss. Birds have other behavior adaptations to staying warm in the winter such as huddling together and nesting in trees or bushes that block out some of the elements. Birds can also go into facultative hypothermia or torpor by dropping their body temperature extremely. I continued my walk away from the Homestead Museum and down by a more wooded area that was also close to the Winooski River. As a walked closer to the river edge I spotted a Pileated Woodpecker on a tree trunk. Another species I have been observing all winter long. As I got closer to it, I must have spooked it, and it flew away before I could get a picture. I then heard a Northern Cardinal vocalizing somewhere nearby. I tried to locate the bird but was unable to, but recorded some audio of it. When I got to the river bank I saw two Mallards swimming around in the river. Mallards are another year-round species here that are able to survive the cold winters through adaptations. The Mallard has enough body fat to not freeze.
I continued on my walk away from the river and got to an area with some more trees. I heard a Red-winged Blackbird call and then looked around and saw the bird perched in a tree. The Red-winged Blackbird is a bird that migrates from Vermont. I did some research and read that the male Red-winged Blackbird arrives back up north before the females do. They also migrate around 500 miles south in the fall. 500 miles south of here would be a warmer environment than Vermont in early March. Even though it is springtime here the weather is still very variable and we have had some cold days. I would imagine that it is an adjustment for the birds to arrive back here in early spring. Although the weather is still slightly cold the ground is thawing and the trees are beginning to bud, and wildlife is becoming more active. All of these components allow for the birds to do okay in the northern climates. Different species of birds migrate in different ways. Facultative migratory birds may or may not migrate depending on conditions and often migrate different places while obligate migratory birds migrate at the same time each year and return to the same places on either side of the migration. Both migration strategies can be seen in long-distance migrants and short-distance migrants but often long-distance migrants are obligate migrants.
I kept on walking and saw three Common Grackles but was unable to get a good picture of them. Common Grackles are another migrant bird. They migrate from Vermont to more southern states. I went to Florida a few weeks ago and saw hundreds and hundreds of Common Grackles and after further research discovered that they are year-round residents of Florida. When I looked at migratory maps for Common Grackles I noticed that in southern Vermont, they can be permanent residents while in northern Vermont they just spend the breeding season. Migration depends on the daylight along with resource availability. As the days become longer birds start preparing for the mating season and migrate back north. The photoperiod is critical in the bird’s migratory behavior. For some of the obligate bird species they do not return north for a bit longer, but some have already returned. There are both advantages and disadvantages for birds to return in early spring. When arriving early there is less food and resources available due to the variable weather and growing season. One of the advantages of early migration is having more territory and nesting options. If birds arrive too late in the migratory period, it may be challenging for them to locate a good nesting spot for the breeding season. Food and nesting area are the two main drivers of migration and Vermont in the winter has limited food options.
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