Bird walk 1. February 17 2020

On February 17th, 2020 at 10:00am I left for my 90 Minute bird walk. At the time the temperature was a moderate 24° Fahrenheit with blue sunny skies and little cloud cover. Wind was approximately 5mph out of the north. During this 90 minute walk one thing I particularly keyed in on was the flight pattern of the unidentified hawk. During the 3 minutes I observed this hawk maintained a constant altitude while circling above, while rarely flapping its wings. This entire time, both its wings and tail fan remained fully opened to maximize the amount of lift it experience from gliding. The hawk seemed to have very large rounded wings which would minimize turbulence around wing tips, therefore minimize drag. I hypothesis this style of flight allows hawks to spend a great deal of time in the air searching for prey, while minimizing the amount of energy expended to maintain a constant altitude. This is drastically different from the flight patterns of the Black-capped chickadees which I observed rapidly flapping wings to flitter from branch to branch seemingly to only satisfy curiosity. I speculate rapid movement among black-capped chickadees and other song birds observed, while energetically costly helps them to avoid predation by being able to outmaneuver their large predators in dense tree canopies. While this particular style of flight doesn't seem to be individual to any species of song bird, it would help the observer narrow the possibilities down on a quick glimpse of a bird in flight. Another particularly interesting flight pattern I observed was that of the pileated woodpecker, and hairy woodpecker. Both species of woodpeckers while flying through the woods and open field seemed to have great elevation change on each stroke of their wings followed by a period of tucking and gliding after every elevation gain giving the impression that the woodpeckers were bobbing up and down as they flew. I cannot hypothesize how this style of flight might fit with woodpeckers particular niche, but from what I observed it seems to be practiced only among woodpeckers. Lastly the best observation of flight I had was that of the American crow. From what I saw it appeared the crow was able to extend its wings and fan and glide similar to a hawk but far less efficiently, and also tuck its wings to allow maneuverability among tree tops similar to but not nearly as well as a songbird. Because of this I believe crows flight pattern to be that of a generalist which would allow them stay airborne for long periods of time searching for food, as well as maneuver among treetops to avoid predation. I found studying birds flight patterns to be particularly useful, as it provides a way of quickly identifying a family of birds when rapid movement prevents the observation of markings. While I did see a great number of birds during this observation session, I was not able to closely study bird markings. I believe this was due to my choice of location. the area I was in was mature conifers with a lack of secondary growth. Without secondary growth it seemed birds didn't stray from the tree canopies which prevented me from getting close observations of any species.

Publicado el febrero 17, 2020 07:00 TARDE por thatchermorrison