Thermal imaging study reveals new function for bird’s distinctive front end
Toco toucans have a huge cooling bill. But it’s the good kind.
While overheated people crank up their air conditioning, toucans increase the blood flow to their supersized, uninsulated bills, report Glenn Tattersall of Brock University in St. Catharines, Canada, and his colleagues. Extra heat radiating from the bill keeps the bird comfortable.
When the bird no longer needs a big chill, blood flow slows, the researchers say. They present, in the July 24 Science, thermal imaging of bills changing temperature.
This new study adds an “entirely plausible” twist to a long-standing subject of debate, says morphologist Winston Lancaster of California State University in Sacramento. “I suspect that few people have ever seen a toucan without wondering, ‘Why the beak?’”
But documenting cooling powers for the toucan bill doesn’t mean other ideas for its function are wrong, says coauthor