Snagging insects, hummingbird style

Zip! Hummingbirds can fly so quickly, it’s sometimes hard to see them darting back and forth.

A new study with high-speed cameras has turned up some surprises—not about how hummingbirds fly but about how they catch bugs. The birds’ lower bills appear to be more flexible than scientists expected.

A ruby-throated hummingbird.

The shape of the hummingbird’s beak has long puzzled scientists. Straight and narrow, it’s designed perfectly to probe deep inside certain flowers, where the nectar is. Nectar alone can’t supply a hummingbird’s energy needs, however. They need protein from insects, too. Yet, their bills don’t appear to have the proper shape for efficient bug catching.

To get a closer look, scientists from the University of Connecticut in Storrs put three species of hummingbirds in big tanks. Fast video cameras that snap 500 frames per second recorded the birds’ every move. Then, the researchers released insects into the tanks.

To catch a fruit fly, a ruby-throated hummingbird (left to right) opens its bill and then widens its gape and adds extra downward slant to the lower jaw.

Gregor M. Yanega/University of Conneticut

The footage showed that the birds don’t nab insects with the tips of their beaks. When a hummingbird goes for an insect, it rushes at it with its mouth wide open. And the lower half of its bill bends downward part way along its length, even though it has no joint.

The hummingbird videos showed that the most successful captures involved snagging the insect close to the mouth end of the bill.

Hummingbirds deserve more attention as serious hunters, the researchers say. The birds do much more than just flit from flower to flower or poke into blossoms to extract nectar.