UVM Ornithology Field Journal 2: Flight
Today we walked from outside Aiken on central campus down to redstone campus, then looping back through athletic campus before returning to Aiken. The habitat throughout was residential, with scattered trees including crabapples, maples, and ornamental species. UVM campus gives way to suburban sprawl and downtown Burlington. The weather was overcast, a wet snow was coming down, and it was 30 degrees Fahrenheit.
We had the opportunity to view birds with very different flight patterns. Ring-billed Gulls have wings with high aspect ratios, and the individual we spotted was seen gliding on its long wings and occasionally flapping, aiding in its ID from a distance. High aspect ratio wings are useful for birds adapted to soaring across open habitats for long distances (e.g. bodies of water), as their long wing shape minimizes the need for energetically expensive flapping. By contrast, we also saw American Robins and an American Crow, both of which had elliptical-shaped wings. Their wing shape necessitates frequent flapping (vs. the gliding motion of high aspect ratio wings), and perhaps is useful for frequently landing and taking off (but not flying long distances continuously) as birds seeking scattered food resources must do. The flight of American Robins superficially resembles that of the Common Redpolls we saw in that they will tuck their wings and dip downwards between wing beats.
The undulating flight pattern of finches is highly diagnostic of the group; we used their distinctive flight pattern in tandem with calls to identify several small flocks flying far overhead as Common Redpolls. Undulating flight creates an up-and-down pattern as the birds alternate flapping with tucking the wings and free falling. Woodpeckers, I noticed, also exhibit this flight pattern. It's unclear to me how this flight pattern relates to the ecology of the birds--perhaps it combines the maneuverability of flapping flight with the energetic savings of gliding?
