Field Observation 4: Migration
Time: 12:00-4:00
Date: 4/5/19
Location: Lewis Creek, Ferrisburg VT
Weather: Cloudy, 40 degrees F
Habitat: Open meadow, forest edges, sparse trees, shrubs, riparian zone
I combined this bird walk with a fishing expedition to Lewis Creek, and I ended observing many more birds than fish. Th noticed many Black-capped Chickadees, a year-round Vermont resident during my walk. Chickadees, like many other birds that forego migration, save energy by not flying hundreds of miles each year. However, this means that they must be able to utilize the minimal available resources in Vermont during the winter. They are a generalist species, eating a variety of foods, ensuring they will always have something to eat. They will consume, seeds, berries, other plants, insects, suet, and sometimes bits of animal carcasses. They also need to be able to survive the harsh winter conditions present in Vermont during the winter. This means they need feathers that will keep them warm and they remain very active.
As I arrived at the river, I immediately noticed an Eastern Phoebe on the ground hopping around in fallen goldenrod and grasses. As I approached to take a picture, the Phoebe moved into a nearby tree, then across the river. On the far river bank, the Phoebe began foraging on the sandy shore. Eastern Phoebes are short to medium distance migrants, overwintering in the southern US and Mexico. The one I saw will stay in Vermont to breed most likely, being close to the northern extent of its breeding range. A variety of ultimate factors (food type and supply, climate) and proximate factors (habitat, vegetation) and well as the bird's circannual cyle influence migration.
I also saw 3 Great Blue Herons flying overhead and one in the river. These birds are just arriving from their migration. Great Blue Herons are partial migrants, moving to more southern parts of their range to overwinter. Since they eat mainly aquatic animals such as fish and amphibians, they need to be in a place where water is non frozen and their prey is active. Therefore, they can't stay in Vermont for the winter.
Mini activity: Eastern Phoebe: as far as 2,000 miles
Great Blue Heron: as far as 1,000 miles
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