Appearance & Behavior

Birds were the first flying machines. They knew what to do before the Wright brothers built the first airplane. Through the millennia they have evolved to be built for what they need to do. This is reflected in the size and shape of their heads, beaks, wings and legs. This branch of biology is called “morphology,” or the study of living things, their form, and the relationships between their structures. By observing carefully, it’s easy to see that the birds’ bodies evolved to match their behavior and natural environment. Let’s take a closer look.

Adult interior least tern and chick. Photo by Michael Forsberg.

Interior least terns are elegant, white birds with a black cap and white forehead patch. Terns eat fish, so they have a chisel-like beak for stabbing and catching fish. And because the tern relies heavily on water for feeding, they have webbed feet.

A day-old least tern chick banded by biologist Lauren Dinan, who is monitoring the colony. Photo by Michael Forsberg.

Terns have evolved to be birds of flight. They need to be able to hover, dive, capture fish and fly back to their nests and feed their young. They have long, narrow, elegant wings that allow them to hover, almost like a helicopter.

Adult interior least tern spreads its wings. Photo by Michael Forsberg.

Terns’ wings are built to travel long distances since they migrate thousands of miles from the Central U.S. to South America where they spend the winter.

Interior least tern migration map. Map by the Tern and Plover Conservation Partnership.

A piping plover sits on its nest. Photo by Michael Forsberg.

Piping plovers have short, stocky bodies with white undersides and a grayish, tan back; they have a single black necklace. While some bird species, such as the cardinal, have different coloring for male and female, the only way to determine the sex of piping plovers is to look closely at their beaks. The males have a distinct vertical line dividing the orange and black color; the females have a feathered or blended division between colors. Because plovers eat insects, the beak is just long enough to probe into wet sand to get bugs and worms.

Male piping plover on the left, female on the right. Photo from the Nebraska Game and Parks Commission.

Piping plovers spend their winters on the U.S. Gulf Coast and southern Atlantic coasts, and because they don’t migrate as far as terns, their wings are a little shorter and more rounded.

This map shows the wintering locations for the piping plovers banded along the lower Platte River in eastern Nebraska. Map by the Tern and Plover Conservation Partnership.

Piping plovers like to run. They have adapted to move very quickly, so they have very long, slim legs.

The piping plover adult and chick have long, slim legs and are very mobile. Video by Michael Forsberg.

When it comes to protecting their young, the terns and plovers are perfect parents. Both defend their nests in unique ways. The tern will dive-bomb and defecate on intruders. They are very aggressive. The plover, on the other hand, uses a broken wing trick called “feigning” to lead the intruder’s attention away from the nests and chicks. They pretend to be injured and make alarm calls.

Adult plover using a broken wing display or “feigning.” Photo by Mariah Lundgren.

Interior least tern dive-bombing biologists Lauren Dinan, Lindsay Brown and videographer Peter Stegen. Video by Mariah Lundgren.

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