Birds have an amazing ability: flight. They use their wings, equivalent to our hands and arms, to lift themselves into the air and keep themselves aloft. But they still need to be able to do all of the things that mammals use their forelimbs for, and for that, birds have beaks, also called bills.
A bill has an upper and lower jaw bone covered with toughened skin. The edges of each bill may be serrated for cutting, grooved and etched for grasping, or smooth. On some species, edges are soft, pliable, and loaded with nerve receptors that can detect what is moving through the bill. This allows birds that siphon their food from murky water to detect food even when it is not visible.
The bill’s skin sheath constantly exfoliates, or peels. New skin constantly grows from underneath, drying and hardening to replace the old skin. Excess layers of skin grow at the bill’s tip where most of the wear and tear takes place. Skimmers, of the genus Rynchops, have bills that grow at twice the rate of other species. They feed by trailing their lower bill in the water as the fly, wearing the skin down at a faster rate. Other protuberances and colors may enhance the bill. Atlantic puffins, Fratercula arctica, grow a bright orange, yellow, and black bill extension only during breeding season.
Bill shapes vary greatly among bird species and are used in a variety of ways for feeding……
Pelicans, genus Pelecanus, have hooked upper tips and a large pouch hanging under the lower jaw allowing them to scoop slippery fish out of the water and hold onto them.
Pelican hooked tip & pouch by McCaig, Getty Images
The long-billed curlew, Numenius americanus, has a slim, curving bill that can reach deep into sand and mud for insects, clams, and small crustaceans.
Curlew probing the beach by Dypics, Getty Images
The American oystercatcher, Haematopus palliatus, can pry open oysters and other bivalves.
Black oystercatcher with clam by Victoria Morrow, Sep 2020
Ruby-throated hummingbirds, Archilochus colubris, have long, slim bills for probing deep flower nectaries to sip the nectar inside.
Ruby-throated hummingbird, Archilobus colubris, by Mattcudaphotos
Whippoorwills, of the family Caprimulgidae, have bills fringed with bristles to catch insects by swinging their bills left and right while in flight.
Bills make great multi-use tools for many other daily activities. These may include preening, building nests, digging, turning eggs over, defending oneself, attacking prey species, scratching, assistance when moving and climbing, and displaying color and shapes during courtship and breeding. Other bill shapes are shown on the Jurica-Suchy Nature Museum’s ‘Bird Beak Adaptations’ slide below. Come to the museum to learn more about these wonderful adaptations and other fascinating birds facts.
