Something Wild: Traveling with Broad-Winged Hawks

Jan 13, 2017

New Hampshire’s Pack Monadnock is one of the best places in the state for hawk watch. Most of the migrating raptors in northern New England and northeastern Canada follow the trail of thermal updrafts that take them over this peak. Last fall, more than 13,000 raptors were counted from the hawk watch station at Pack Monadnock, and more than 10,000 of them were broad-winged hawks. And this year, Eric Masterson decided he would follow them on their journey south, on a bicycle. Eric is a biologist with The Harris Center for Conservation in Hancock. 

We caught up with him in Mexico, taking a break from the bicycle to brush up on his Spanish. “I’m in San Cristobal de las Casas (in Ciapas provence) a town of a quarter million people. It’s cold because I’m at about 7,000 feet elevation.” Masterson left New Hampshire in early September about the same time and from about the same place as the broad-winged hawks begin their southward journey. They make the trip in about six weeks, he’s taken four months to get down there.  

Credit Courtesy Hawk Mountain Sanctuary

But he doesn’t mind that his journey’s taken a little longer. “They’re incredible. I knew from the get go I was not going to be able to keep up. What I wanted to do was cycle the route, which is a pretty narrow route down the Appalachian [mountain range] to the Gulf of Mexico.” There were a few birds that had been outfitted with transmitters and who were dropping GPS points every day, and Masterson discovered that they follow the Appalachians faithfully until they reach Alabama.

Broad-winged hawks don’t so much fly south as glide south. As Masterson points out “the physics of flight are such that a hawk will spend 30-percent more energy flapping south to Brazil than it will gliding. They don’t have to flap because they have a series of elevators, which are columns of rising hot air. They find these columns which bring them up 2-3,000 feet, then they glide down and find another thermal.” In Alabama the mountains run out, and somehow the broad-winged hawks speed up. “The thermals in the flat states can go to 10,000 feet or more. If you start from 10,000 feet you can glide a lot farther.”

A common site over Pack Monadnock in the fall.
Credit Courtesy BobMacInnes via Flickr/Creative Commons.

  Masterson is not prone to superlatives, but when speaking of bird migration he can’t help himself, “I think it’s one of the most phenomenal natural history spectacles on the planet.” Masterson describes his voyage as a pilgrimage of sorts, “I wanted to honor their journey through my journey.” And he finds himself confronting some of the same challenges the birds are. For example: Language. Yellow is often nature’s way of saying “leave me alone,” although yellow spotted-salamanders in New Hampshire are not toxic. “However you take that broad-winged hawk and put him in Costa Rica and you see the yellow spotted frog that could be highly toxic species of amphibian.” Masterson’s own struggles with language as he began encountering different human cultures south of the border, but even the birds sound different down there so he’s been learning new languages of the birds, too.

Another parallel between Masterson and the broad-winged hawks are finding a safe, warm place to stay for the night. “In Mexico, there are two cardinal rules: don’t go out at night and don’t drink the water. So I don’t go out at night.” Masterson is off his bike and inside by 4:00 each afternoon. As he points out, “nocturnal song birds migrate at night to avoid predators and I migrate during the day to avoid predators.” 

Masterson is hoping to ride all the way to Panama before returning to New Hampshire – by plane.