Birds With the Weirdest Bills, Just in Time for Tax Day

Only one bird of some 10,500 species has a bill that points sideways.

It’s tax time in the U.S., and Weird Animal Question of the Week thought folks might like to think about another type of bill for a while.

We wondered: “What are some of the world’s weirdest bird bills?”

Beak Unique

To clear things up, a bill and a beak are synonyms; both refer to a bird's jaws and their horny covering.

And within the world's 10,500 known bird species, some species have bills like no others.

The wrybill of New Zealand, for instance, is the only known bird with “a bill that bends sideways," says Bob Mulvihill, an ornithologist at the National Aviary in Pittsburgh. It may look funny, but it's all the better for reaching tasty mayflies hiding under river rocks.

Many birds have downward-facing, or decurved, bills, like hermit hummingbirds, whose “bill is an exact fit to the curvature” of the flowers on which they feed, Mulvihill says.

Few birds have upward-curving, or recurved bills. South America's endangered bush-billed bird is said to have a Mona Lisa smile, and wide-ranging avocets use their thin, upturned bill to sweep through shallow water, catching tiny prey.

Perfect Fit

If you haven't noticed already, bird bills can tell us a lot about their lifestyles, Mulvihill says.

The black skimmer of eastern South America is the only bird with an underbite: A longer lower bill than upper bill. This helps the species skim the water for prey in flight.

A group of finches called crossbills have upper and lower bills that criss-cross instead of fitting together cleanly, an adaptation for wrangling seeds out of pine cones.

Despite its namesake shape, the roseate spoonbill’s beak is “used more like a pair of salad tongs,” which the bird swishes in the water, partially open, to snag its prey, Jerome Jackson, behavioral ecologist at Florida Gulf Coast University, says via email.

The shoebill stork of Africa’s Great Lakes region has a shoe-shaped bill so big Mulvihill says "it would fit Shaquille O’Neal.”

Shoebill Stork

What do they eat with those bills?

“Pretty much anything they want,” Mulvihill says, but they really like baby crocodiles.

Reduced Bill

Bills aren't only for eating, either.

The rhinoceros hornbill of Southeast Asia has a casque, or helmet, on its bill. Sound echoes through this “mostly hollow, honey-combed chamber and amplifies” the birds’ calls,” Mulvihill says.

Both male and female puffin of northern climes sport a bright "comical-looking bill" to attract mates, Mulvihill says.

“But in the non-breeding season, they lose those colorful, horny plates,” so their bill “becomes much less exaggerated and eye-catching.”

A reduced bill. Jealous much?

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