As thousands of hawks migrate high in the skies across Texas, they thrill us as do few other birds.

Part of what enthralls us about hawks is the sheer energy of their flight. If we crane our necks to the sky in September, we may see a group of 500 or even several thousand broad-winged hawks soaring together in upwardly spiraling circles called kettles that move southward at an elegant but rapid pace as though in a choreographed sky dance.

Broad-winged hawks and many other hawks, falcons and kites — collectively called raptors — come our way from breeding grounds in the eastern half of North America. They follow the Mississippi Valley down to the Louisiana coast, then take a sharp westward turn toward Texas and follow the coastline until they get to Galveston Bay.

Not wanting to cross the formidable bay, the hawks swoop around it and cross skylines in Houston and down to Corpus Christi. They circumvent Corpus Christi Bay, catch the thermals over the Nueces River and hasten south to Latin America.

Some hawks come from the West, like the Swainson's hawks that arrive from the western Great Plains and Rocky Mountains, where they breed in such places as grasslands and farm fields. They soar through South Cen tral Texas on long, pointed wings held in a dihedral or “V” shape.

Pale bellies, tawny bibs and light-colored underwings offset by dark flight feathers give Swainson's hawks a rich, two-toned appearance. They carry the nickname “grasshopper hawks” because of their vigorous consumption of grasshoppers and other insects on the prairies and fields over which they migrate.

I've often seen large numbers of Swainson's hawks circling behind tractors plowing farm fields between Corpus Christi and San Antonio. The hawks were after insects stirred up by the plow. I've also seen the hawks roosting on the ground in an open grassland while resting before the next day's continued journey south.

Hawks journey far. Swainson's hawks typically go all the way to the pampas of Argentina, a distance of some 6,000 miles from their breeding grounds. Broad-winged hawks travel to southern Mexico, Central America and all the way to Peru, a distance of some 2,000 to 4,000 miles from their breeding grounds. Talk about energetic flight!

But nothing is more energetic than a peregrine falcon, zipping from northern breeding grounds through our skies at speeds exceeding 30 mph. Whereas many peregrines and other migratory raptors speed to Latin America, some of them stop for the winter right here in Texas.

To contact college dean Gary Clark or photographer Kathy Adams Clark, visit their Web site at