Flight and Wing Physiology

I went out on Monday 2/17/2020 for an hour and a half starting at 12:15 pm. I was in a fairly forested area with a decent mix of deciduous and coniferous trees. It was 27 degrees Fahrenheit out and very sunny. There were occasional clouds. There was a slight northeast breeze at about 5 miles per hour with occasional stronger gusts. I was in East Montpelier around a residential property but then moved onto some recreation trails.

I started near the residential property and was having difficulty locating any birds, although I could hear distinctly 3 black-capped chickadees calling from high up in the trees. I was wondering if the reason for their timidness was because there are two domesticated cats that live on the property. They predate on birds. Further, the property is surrounded on all sides by roads, creating a very small fragment of land. For edge sensitive species or species with large ranges, this may not be ideal territory. I decided to move further away from the range of the cats and into a more continuous wooded area to see if this provided better success, and it did.

I observed 10 Black-capped Chickadees while along the trail. They traveled in groups of 2-4. They were foraging within the trees for seeds. They jumped between branches or used a few quick wing flaps to propel them to nearby branches. They had elliptical wings which allowed for easy maneuverability through these dense trees. In contrast to the Black-capped Chickadees, the singular Common Raven had fewer flaps of its wings. I saw it gliding through the air. Its wings were more like slotted high lift wings, the primary feathers splaying out towards the end of each wing. This provides better lift which they can utilize to keep them aloft while simultaneously minimizing stalling during flight due to consistent air foils created by the primaries. This allows for gliding which can be conducive to their method of foraging, including scouting for carrion among other food sources down below. This demonstrates how clear differences in wing physiology can play into niche differentiation. Smaller elliptical wings are conducive to short flight and easier maneuverability through dense vegetation while slated high lift wings are more conducive to gliding in open air.

Publicado el febrero 18, 2020 06:46 TARDE por emerrylees