Archivos de Diario para febrero 2020

17 de febrero de 2020

Birding In Charlotte: A Quest For Hawks And A Look At Bird Flight

On February 10th, 2020 I went birding at a new location off of Ferry Rd in Charlotte, VT that I have never been before. My initial intent was to simply scan the nearby fields for signs of Rough-legged Hawk, but once I got out of my car to scan the distant tree lines for birds of prey, I heard a familiar call note flying overhead. Eastern Bluebirds! The temperature was 34 degrees Fahrenheit with a stiff south wind at 5-15 miles per hour. Overcast skies made it difficult to discern any real colors on birds in flight, but once it dropped below the horizon and landed in a nearby sumac tree, I could see the brilliant blue coloration on the bird's head, wings, mantle, and tail, contrasting nicely with a brown breast and white belly. Flying with slow, shallow wing beats, it almost seemed physically unlikely that the bird could remain in the air. Relatively long, pointed wings probably allow for this flight pattern, as they provide the bird's small body with ample lift. It's somewhat erratic bouncing flight makes it hard to believe that they are as nimble and agile as they are in the air. Eastern Bluebirds are birds of open landscapes, especially in during the breeding season when they are primarily aerial insectivores. But in the winter, Eastern Bluebirds flock to road side sumacs and berry producing bushes. Although, long pointed wings with a lot of surface area, may not be the best for zipping through thick undergrowth and weaving in and out of trees in a dense forest, they offer great speed and agility when chasing insects through the open air. While bluebird flight pattern is quite distinctive, it is much easier to make a confident ID when you take into account other aspects of the bird, especially flight calls, which Eastern Bluebirds are known to make.

A scan of the distant tree line resulted in the discovery of 3 Red-tailed Hawks. One of which took off from a treetop just 50 yards away and began circling over head. 3 to 4 powerful wing beats followed by a soar. The bird used it's broad buteo tail as a rudder in the air to tilt it's body toward the center of rotation. I find it hard to imagine that without any direct sunlight or general warming effects from the sun, that there were any thermals for this large adult Red-tail to ride high into the sky, but that's what appeared to be taking place. More likely, the hawks' wings with their high lift primary feathers and high surface area secondaries and covert provided the bird with enough lift to gain altitude without hardly any effort. Red-tailed Hawks, along with the Eastern Bluebird are open land specialists, but in a very different way. While Eastern Bluebirds rely on their wings to be able to sally out from a fence post or branch to catch a passing dragonfly, Red-tailed Hawks rely on their wings for soaring high above open fields and being able to control and hoist larger prey. The flap-flap-glide flight pattern of the Red-tailed Hawk is easily distinguishable from other birds of prey and larger birds in general. The rounded tail that is spread out in flight while the bird glides and the fingered wingtips are characteristics often seen in birds of the Buteo genus along with some vultures and members of the eagle family and even Common Ravens in some instances.

The Rough-legged Hawk is also a member of the Buteo genus along with the Red-tailed Hawk and is known to share an affinity for open landscapes and farmscapes during the winter months. With a flight pattern very similar, if not identical to that of a Red-tailed Hawk, when I saw one of the RTHA take flight for the first time, my heart jumped. "Could it be! My first Chittenden County Rough-legged Hawk since December of 2018?" Right size, right shape, right wing beats, and... nope, totally wrong color pattern and lacking the classic coloration of a RLHA and... a red tail. Rough-legged Hawks breed in the high arctic and parts of Alaska and only winter in the lower 48, so my chances at seeing this amazing species are limited to only the cold winter months from November to Late-March and Early-April (eBird.org).

Yet another bird with a distinctive flight pattern that I saw during this outing were American Goldfinches. These tiny finches are year-round residents in VT and do not need to migrate. Nonetheless, they are quite speedy in the air. With a high arching, undulating flight pattern, American Goldfinches seem to bounce from side to side and up and down when in the air. Similar to a woodpecker flight pattern, they give a few quick beats of their contrasting black wings before folding them against their body in a momentary free fall. In addition to this diagnostic finch/woodpecker flight pattern, American Goldfinches also have a tendency to make high pitched calls in flight. The classic "a-dee-dee-dee.... a-di-du...." flight calls, made with each burst of wingbeats are a great way to ID American Goldfinches by simply seeing them in a distant flyby.

Anotado en febrero 17, lunes 21:05 por jacobcbirds jacobcbirds | 20 observaciones | 0 comentarios | Deja un comentario

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