Birds of prey: migration of raptors

According to Brett Ewald, a biologist and naturalist of Lakeshore Nature Tours, Western New York is the top raptor migration flyway in eastern North America. Raptors migrate from the south to the north to breed in the spring.

BARKER — With rising concerns about the Lighthouse Wind project, and how it will affect migrating birds in the area, Save Ontario Shores hosted a free, public presentation on raptor migration Thursday evening at Barker High School.

According to Brett Ewald, a biologist and naturalist of Lakeshore Nature Tours, who lives in Yates, Western New York is the top raptor migration flyway in eastern North America. Raptors migrate from the south from South and Central America, and the southern United States to the north to breed in the spring.

“There is a larger migration in the fall,” he said. “The hawks have had young, and a lot of those young are migrating south. A lot of those young are not going to make it to the following year, so there isn’t as much raptors coming north in the spring.”

According to Ewald, raptors don’t like cold water, so they fly over land. When the birds hit the lake, instead of flying over, they go around.

“These hawks are heading north, they hit the lake and they don’t want to go over it, they go around it,” he said, gesturing to a map showing the Western New York region on the screen. “We get a little bit of a flight that goes to the west, but a majority of these birds go to the east. A lot of it has to do with the fact that the prevailing weather systems in North America are west to east.”

The best time for a raptor watch is when a low pressure system is passing to the north, warm temperatures ahead of an approaching cold front, southerly winds preferably above 10 miles per hour and sunlight.

Ewald said raptors use thermals — rising warm air. By catching the warm rising air and soaring up to the top, the birds can glide in the direction they want to go until they get to the next thermal.

“They can cover hundreds of miles in a day and only have to flap a few times,” he said. “That’s why the cold air over the lake is such a factor they can’t get over; there is no thermals over Lake Ontario.”

Raptors are not flocking birds; Ewald said the birds are individuals migrating using the same flyaway.

“Their goal is to get to the breeding ground, set up territory and mate,” he said. “They’re not like some of the other ones who actually travel in family groups and stuff. So when you see large groups together — we call a large group in a thermal a kettle. It got that name because it looks like water boiling from all the activity. Those birds aren’t sticking together; they’re using that same thermal.”

The trickiest part of raptor watching is identifying them in flight.

“It’s how (the bird flaps), how it holds its wings, the size of the bird,” he said.

While each species has its own identifying marks, the seven main groups which bird watchers go by are: buteos, accipiters, falcons, ospreys, eagles, northern harriers and turkey vultures.

Ewald explained buteos are soaring hawks with long, broad wings and short, wide, fanned tails. Accipiters are hawks with short, round wings and long, rudder-like tails. Falcons have long, pointed wings and most commonly flap when flying. Ospreys have long, narrow wings which form an “M” shape. Eagles have notable long, broad wings which are held flat while soaring, and their large heads and beaks can be seen from a distance.

Northern Harriers hold their wings above their body in a shallow “V” shape. Turkey vultures also hold their wings in a “V” shape, but rock in flight while in thermals.

Ewald started bird watching in Ransomville in the early 1980s.

“We lived about four and a half miles from the lake, and I realized I could go right out in our backyard and count (raptors),” he said. “I was counting them on the school bus on the way to and from school, and then it turned into college. After college I did a number of jobs across the country for Hawk Watch International.”

Ewald pointed to the multitude of resources available to interested bird watchers, suggesting the numerous raptor guides on the market.

June Summers, president of the Genesee Valley Audubon Society, asked residents to become citizen scientists.

“We don’t expect you to be experts. We hope you can just count the bodies more or less as (the raptors) go over,” Summers said. “The reason we are doing this is because Apex has done this raptor survey. I looked at the criteria they used to do their raptor survey, and I believe (Ewald) did too.”

“I sent in a six page response to their survey, pointing out where they were delinquent in their efforts in terms of effort made,” Ewald responded.

As a result, more data is being sought to see what raptors travel through the area.

Those interested in helping to count birds, or simply want more information, contact Summers at (585) 865-6047 or

Source: http://www.thedailynewsonli...

APR 2 2016
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