Field Journal 4

Katelyn Beskind
Field Journal 4

Field Journal Basic Information
Date: 3/24/2024
Start time: 1:10pm
End time: 2:17pm
Location: Centennial Woods

Weather
Temperature: 32 degrees Fahrenheit
Wind speed & direction: 1mph NNE
Precipitation: Not raining or snowing
Humidity: 43%
Visual appearance: Clear skies

Habitat(s):
1. Coniferous stands
2. Mixed coniferous deciduous edge
3. Mixed coniferous deciduous
4. Urban (Cedar Waxwing)

Prompt Response
Over winter I saw mainly passerine species and occasionally some hawks. These species would forego migration because the cost of migration would be much greater than the cost of staying behind. Migration is an inherently dangerous activity, since it requires a lot of energy (and therefore food) and increases the chances for individuals to become injured or lost due to weather, disease, lack of resources, etc. Additionally, migration wears on feathers, which would then need to be replaced before migrating again. Therefore, it is more advantageous for some species to not migrate. To overcome winter, birds must secure a source of food and ways of maintaining heat. Like humans, birds can shiver to retain heat, spend time in the sun to warm up and maintain feathers to insulate their bodies. Additionally, birds may seek shelter in tree cavities or in groups to protect themselves from weather or heat loss. To keep their energy up, birds must forage for insects, nuts, and seeds from trees. Some birds cache food for winter, while others forage consistently.

Facultative migrants are coming from southern locations such as the southern United States or South America. These places have warm winters with abundant food to offset the cost of migration. Obligate migrants lose their food source in breeding locations during winter, which forces them to move to be able to survive. For these species to return to Burlington, the weather would need to warm slightly, and other food sources (fruits, insects, fish, nuts, etc.) would need to become more abundant. While food is available for species in winter, not all species can survive on that food. As a result, the food source for an individual species would need to be replenished enough for the species to survive.

An advantage of these species arriving in Burlington in late March / early April is that they could become re-established before other species have and begin to capitalize on available resources. It could also be advantageous for territorial species to come early so they can establish territories and find nest sites first for breeding. Some disadvantages would be the potential for difficult weather and lack of food. It is still possible to have below-freezing temperatures and snowstorms in Vermont during this time, which could be a problem for these species that are not as adapted to winter in Vermont. Additionally, food may be more limited during this time due to inclement weather or because the food has not fully recovered yet.

Most of the species I found today are permanent residents, although some may migrate if needed. For example, Black-capped Chickadees, White-breasted Nuthatches, Northern Cardinals, and Tufted Titmice do not migrate. However, American Robins, Cedar Waxwings, Red-breasted Nuthatches, and Brown Creepers can be residents or migrants. As a result, I will calculate the distance for the previous four species as if they migrated for sure, even though some may not migrate. Since the wintering ranges of these species are quite varied, I chose general locations in the southeast United States. The total migration distance for these species was 3918.65 miles. This is very rough since ranges can change and each of these species may stay in Vermont anyway. However, it is cool to think about how far these birds could have collectively flown.

Publicado el 24 de marzo de 2024 por katelyn282