River of Raptors

River of Raptors

One of the world's greatest wildlife spectacles takes place every autumn as millions of hawks and other soaring birds funnel through Veracruz, Mexico, where a pioneering program aims to keep them flowing for millennia to come.

By Susan McGrath
Published: September-October 2010

On a hot day here thermals can be half a mile across and 10 times higher than they are wide. Their vertical wind speed can exceed nine miles per hour, and as many as 2,000 hawks and vultures can be soaring in a column within one, all turning in the same direction. "Kettles," hawkwatchers call these upwelling air columns that boil with rising birds.

A kettle is forming now, below and east of us. We dive into the car and pelt down the road. Unfazed, our professor continues his explanation at a dignified shout from the front seat. "When the birds are soaring in a thermal, they're actually falling. But within the thermal the air is rising faster than the birds are falling, so they're carried upward. They're not making forward progress in the kettle, though. At some point they have to peel out of a thermal and glide to another."

How do they know when to peel out? "This is what they do," interjects Burns, an ardent paraglider. "And besides, if you stay in too long, you get sucked up to 20,000 feet and struck by lightning and beaten by golf ball-sized hail stones and spat back out, probably dead."

"Precisely," Templeton says. "So they rise in the kettle. Then they cut out of the kettle in a line, sometimes 30 or more birds across, gliding and falling toward the south, until they encounter another thermal, and rise again. That's how they travel--soar to about 3,000 feet above ground level, glide to about 1,000, soar, glide, soar, glide."

On the best of days thermal "streets" form--parallel lines of thermals often topped with cumulus clouds punctuating the length of the plain. Hundreds of thousands of birds can be riding down these thermal highways, the sky strung with orderly swags of speckles for hundreds of miles. "Like dirt caught up in a dust devil, making the invisible visible," as the hawk aficionado Scott Weidensaul writes in Living on the Wind.

"Stop here!" Templeton commands.

Under the kettle now, we tumble out of the car. Burns lies down in the middle of the road and starts shooting. Templeton redirects the few cars passing by. I just stand there, neck cranked, jaw dropped, as hundreds of broad-wings billow upward in a vertical gaggle above us, not dramatically close so much as dramatically numerous, and unmistakably hawklike. The kettle is like a swarm of enormous bees, but silent, swift-rising, and all wing. In 30 seconds they've blown to the top of the kettle and begun streaming off the south end of it, like water overflowing from a spout. Their day's journey has begun.

 

The raptors can glide up to 200 miles a day. Toward the end of the afternoon, as the sun descends, so do they, to overnight in patches of forest. Most of the coastal plain's native forest had given way to agriculture by the time Cortez dropped anchor here in 1519, so the big flights of raptors have been roosting in the foothills of the Sierra Manuel Diaz for centuries at least. But in modern times the foothills have been shorn to graze more cattle. Pasture a la Veracruzano isn't the complete wasteland for birds that sugarcane is; nevertheless its scraggly grasses and spindly trees don't work as roosting sites for big flights of raptors.

They don't really work for grazing anymore either, says Rene Altamirano Acosta. Raised in Mexico City, Altamirano studied hydrology and biology at university before coming to Veracruz in 1989 to run the family ranch. Right off he dug a natural tank to sequester rainwater. "The first year it filled to my chin. Well, I thought, next year it'll be better. Next year, my waist. Then my ankle. Then there came a year"--he pats his boot--"nothing but mud. It had stopped raining."

Altamirano is one of many farmers who express concern about diminishing rainfall and unpredictable weather patterns. "We don't know what part of the change is global, what part is local," Altamirano says. "We just know it's not enough rain."

The village of Mozomboa, population 3,000, where Alta-mirano lives, has a nice old grange hall of pink-stuccoed cinderblock. As part of the ongoing Pride campaign sponsored by Audubon and RARE, ProNatura has organized a series of workshops here, bringing together landowners and representatives from government agencies in an effort to preserve habitat in this critical corridor. A key component of the Pride campaign is the training of a young community-development organizer at ProNatura named Adolfo Balcazar. 

As in all Pride campaigns Audubon participates in (see "Taking Pride," below), much of Balcazar's work fosters awareness and education, reaching out to people who live within the IBA to engage them in conserving their landscape. For example, here, where futbol is king and there are no organized after-school activities for children, Balcazar got a soccer tournament going for 120 children from eight lowland villages in the migration corridor. He commissioned radio and television spots promoting interest in nature, and had a peregrine falcon costume made up for "Peri," a popular figure at festivals.

That's the fun part, Balcazar says. Far more challenging, if ultimately most rewarding, is collaborating with landowners to preserve forest.

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