Archivos de diario de febrero 2019

14 de febrero de 2019

Flight Physiology Observation

I had the chance to observe a red-tailed hawk, some gulls, a bald eagle, and a few goldeneyes at Shelburne Farms. The red-tailed hawk was really utilizing the strong winds this day and soaring with it’s head pointed into the wind. It stabilized itself and remained motionless being held up solely by the wind blowing directly at it. They have passive soaring wings with low aspect ratios which allow them to ride currents and not spend much energy flapping. They have slotted primary feathers they move independently to make minor adjustments in flight. Their flaps are slow compared to other birds and infrequent. The gulls on the other hand actually have a similar flight technique but a very different wing shape. Long and tapered and used for active soaring the gulls require wind currents to sustain their flight without flapping. They fly more erratically than a hawk and much faster with the right wind. Without adequate wind however, I know from previous observation that they flap much more often than a hawk would due to their lack of a broad wing surface. A hawk is an open area aerial predator and as such they need to glide slowly and with minimal effort to scan fields for prey. Gulls on the other hand are seabirds and soar on coastal wind currents and munching on anything they can find along the shore. Each has a distinct flight style and wing shape based on their particular habitat niche. Using flight pattern to identify is a very useful thing. If you see a bird flying high in the distance soaring on thermals you will be able to narrow it down to a hawk or eagle. A bird soaring low and fast or flapping about near the shore of a lake or ocean would be easy to narrow down to a gull strictly based on flight pattern. Potentially a big reason why I did not find many birds this day was because of the wind along the lake. I was focused on trying to find ducks but the waves were likely too turbulent for them and many may have relocated to calmer waters. Additionally I went around sunset when most birds are heading back to their nighttime sleeping spots. Additionally, since it is winter many species are simply not around yet as we have fairly few winter residents compared to summer. To have better luck I would ideally get up at sunrise and look around when the birds are most active and explore within the woodlands instead of on major paths and roads.

Ingresado el 14 de febrero de 2019 por michaelmcg michaelmcg | 3 observaciones | 0 comentarios | Deja un comentario

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