Field Journal 5: Migration
Start Time: 4:00pm
End Time: 5:30pm
Date: 04/04/21
Location: Trinity Woods, Burlington VT
Weather: 45℉ and sunny
Habitat: A couple of acres of woods in an urban area. There was a little valley made by two hills with old-growth pine trees. One thing to note was that this area gets a lot of noise pollution from the F-35 jets that fly over routinely.
On a bright, sunny Sunday I headed over to the woods behind Trinity to go birding. I saw a few American Crows, Ring-Billed Gulls, a Mourning Dove, two Rock Pigeons, and a Great Black-backed Gull. I was fairly surprised when I saw the Great Black-backed Gull because it looked like a crow with a white head! But upon further research afterwards, I was able to determine what species it was.
A year-round resident species that I observed was a couple of Rock Pigeons. They do not migrate because they are able to survive in cold temperatures and do not want to expend the huge amount of energy it takes to migrate. To keep warm Rock pigeons fluff up their feathers, creating air pockets around their bodies that insulate them. When they are sleeping they tuck their bills into their back, which helps to keep the heated air trapped around their body. Rock pigeons can also enter a state of torpor. In this state, barely any energy is used and their body temperature drops down to as low as 50 ℉.
A facultative migrant that I observed was a Mourning Dove. Mourning Doves who reside in the northern United States and southern Canada will fly thousands of miles south to Mexico. Individuals who breed in central and southern United States may only migrate a few hundred miles or not migrate at all. However, with warming climates and shorter winters, fewer Mourning Doves may opt to migrate every year. If this mourning Dove did opt to migrate this winter, I can assume that it was arriving in Burlington to either stay for the spring/summer or head more north into Canada. It could have come from as far as Southern Mexico! Mourning Doves migrate in the spring to partake in the breeding season. In addition, they migrate because their survival offsets mortality that would result from not migrating. Warmer weather and widespread new growth that comes with Spring facilitated its arrival to Burlington.
Mini Activity: total miles traveled by all migrants observed
Mourning Dove: 3,480 miles
Notes: Populations who spend the breeding season in the northern U.S. or Canada will fly as far as Southern Mexico for the winter. Populations in the central and southern U.S. may not migrate at all.
Ring-Billed Gull:
Total distance traveled: 1,300 miles
Notes: Ring-billed gulls tend to migrate along coasts and large rover systems. They spend the winter in the southern U.S.
Black-Backed Gull: 850 miles
Notes: Some populations in Massccutes and Nova Scotia stay year-round, while populations in Eastern Canada and Maine migrate south along the coast or to the Great Lakes region. This individual was probably passing through Burlington as it continued its migration to Canada.
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