Tuesday, September 23, 2008

Keen Eyes

On a crisp day last week, we ignored the tufts of clouds threatening possible afternoon rain and drove thirty minutes straight uphill to Harvey’s Knob on the Blue Ridge Parkway. This is not an unusual past-time for us, when we feel we want to get away from the hustle and bustle of city living, but for the next few weeks, Harvey’s Knob will not be as quiet. What is bringing out the crowds? Why, the hawk migration, of course, and it’s a regular bird watcher’s party.

When we arrived, the parking lot was filled with people in their camping chairs, dogs at their feet, telescopes and binoculars trained to the skies. Everyone waved, happy to greet us, and a quick hello got us all the hawk counting statistics we needed to know for the day and most of the facts on last year’s counts from Virginia to Mexico and back again.

People from all walks of life had left their daily grinds to cluster on this particular scenic overlook. Apparently, bird watchers on similar mountain ridges across this vast continent join in hawk counts from mid-August all the way through late November. One couple said they planned their annual vacation around the hawks. They come to Harvey’s Knob every year, leaving jobs as a fire fighter and a school teacher to help HMANA, Hawk Migration Association of America, with their annual count. This year, they will spend two weeks of October in Veracruz, Mexico where the fire fighting bird counter reports, eyes sparkling, that they can see five to six million hawks fly by in one day.

The excitement is contagious. Groups of school students, retired businessmen, a police officer, and several medical professionals spent an enjoyable afternoon with us trading bird watching stories and information on good locations to see Raptors from Alaska to Florida. I found myself teaching some of the students and my mother some tricks on finding the birds with the lenses of their binoculars. Other volunteers patiently described where we all could see the sixth Bald Eagle of the day in a distant break between two fronts of clouds. Everyone, no matter how old or how experienced, felt the thrill when they joined in counting the day’s largest kettle of three hundred Broad Wings as they silently circled over our heads. Imagine our surprise when the day’s count for this one species at this one overlook totaled 3,604.

These stout bodied, brown and beige hawks are one of the first Raptor species to go, leaving their summer breeding grounds in the forests of North America in late August to mid-September. The Broad Wings are not an easy species to observe during their summers here. You will rarely see more than a glimpse of one circling overhead looking for prey. But, they become much easier to spot when they congregate to begin migration. They travel in groups called “kettles” that can number up to thousands of birds, and the groups get larger as they draw closer to their winter habitats.

A recent study by Cornell University used satellite transmitters attached to Broad Wings’ backs to track their migrations. The study found they averaged 111 kilometers or 69 miles a day and traveled over 7000 kilometers to the tropical forests of Central and northern South America. But, once they arrived in their wintering grounds, they inhabited very small ranges staying in territories that averaged just one square mile.

So, if Cornell is tracking these birds, why do they encourage so many volunteers to assist HMANA with their hawk counts? Well, one reason is that birds can be used as indicator species. That is to say, one can study data about their population numbers to track environmental trends and find potential problem areas. With migratory birds, the data collection becomes increasingly difficult when their ranges span continents. But, so too does the importance of knowing their status increase, because knowing if these species' populations are healthy could help scientists identify and address potential environmental issues before they can effect human populations over the many countries where the birds live and migrate.

How does one go about helping with the HMANA Hawk Migration Count? Well, that part is easy. Go to http://www.hmana.org/ to locate a watch area near you. Bring binoculars if you have them, but often you’ll find people with an extra set who are willing to share. You’ll want sunglasses, sun screen, and a comfy folding chair. No prerequisites and no experience necessary, just bring yourselves, your willingness to learn, and your keen eyes.

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