The urban legends abound. Do they really migrate all the way to Brazil each year from the North Pole? Do they really gorge on hormone-laced feed? Do they even have heads?

So much mystery shrouds a poultry staple on Brazilian dinner tables that geneticists, science writers and cooks all find themselves grappling with the same vexing question: What is a Chester, anyway?

Some say the bird is an aberration created by crossing turkeys with ostriches. Others contend that they are fathered by three-foot-tall roosters. Some go as far as to ask whether they are grown on trees in a lab. Photos and video images of living Chesters are intriguingly scarce, encouraging fanciful speculation.

BRF, the food processing conglomerate that sells the Chester, offers some clues about the bird’s true origins. Perdigão, a company that BRF later absorbed in a merger, sent researchers to the United States in 1979 in search of a bird large and meaty enough to compete with the turkey at Christmastime. They brought home the breeding stock ancestors of the Chester.