22 de febrero de 2021

FJ1 Ornithology

Date-2/22/21
Start time-12:40 pm
End time -3:00pm
Locations- Shelburne bay park, North beach
Weather- 26 degrees Cloudy with sustained 15mph winds gusting to 20 lightly snowing

Upon arriving at shelburne bay park a stiff western wind greeted me as I stepped out toward the bay. Hoping to find rafting waterfowl or gulls I scanned the area until the wind pushed me back into the trees. From there I walked through a large older growth pine stand. An opossum slowly waddled across my field of view into its den, but no birds. Finally after about .3 of a mile I got into a more dense hemlock stand where I heard some chirping. After listening for about ten minutes I heard a few tell tale Black-Capped Chickadee calls. I could not get into position to take a picture and the wind made hearing them on video impossible. Moving down the trail taking my time I happened upon an American Robin in a dense hardwood sapling area. Another Robin joined and then another. They did not vocalize with one another, instead they hopped around the same group of trees in a seemingly random order. Eventually they moved further away and my view was obstructed.
I was disappointed with the lack of birds in my hour and a half in Shelburne bay park so I drove to north beach hoping to see some waterfowl. After the cold walk down to the water I was rewarded with two herring gulls riding the strong winds off the lake up and down the beach. They seldom flap their wings and can almost hover when nosed into the wind. They ride the air currents to gain altitude then swoop down next to the water. I could not tell the purpose of their meandering but I would guess they are looking for food. Up the beach I spotted a group of small ducks getting pounded by the white capped surf on lake Champlain. Before I could get close to the ducks they flushed and flew further down the shore. I could not tell their species exactly but they were smaller then mallard or black ducks and they appeared mostly black with some white. My guess was that they were common goldeneye ducks. They were likely in the bay to get shelter from the harsh winds in the middle of the lake. On my way out of north beach park I saw a plethora of American Crows. Many were in trees or on telephone wires, some were foraging on the ground. They vocalized when I walked near them and seemed to be very aware of my presence. They seemed to gather around areas were the snow had melted and the exposed ground was visible.
Comparing the flights of American Robins, Herring Gulls, Common goldeneye and Crows allows a bit of insight to just how diverse birds and their behavior is. The Robins utilize a more elliptical wing. They seldom glide and usually flap their wings very fast when moving around the forest. They're built for mobility and can move around tight spaces easily. The Herring Gull is quite the opposite. Its long, high aspect ratio wing is meant for gliding. It needs wide open spaces like lake Champlain to utilize its gliding capabilities. Its wings are bowed downward so as to minimize wing tip vortexes that would take away some lift. The common Goldeneye appears to be heavy in flight. The duck flaps its wings aggressively and does not stop doing so until it is time to descend or land. Its wing shape is more elliptical as well but this is likely less for maneuverability and more for the ability to take off almost vertically out of water. Finally the American crow has what seems like a medium. Their wings are long enough and high enough aspect ratio for them to glide long distances with ease but also seemingly maneuverable in forests and tight areas. This may be why crows are so versatile when it comes to habitats.

Anotado en febrero 22, lunes 21:54 por andrewzilka1 andrewzilka1 | 4 observaciones | 0 comentarios | Deja un comentario

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