How Birds Beat the Odds

It's a dangerous world for an egg.

Raising a nest of young birds is a lot of work. Parent birds have to keep their eggs safe from predators, shelter the chicks from weather, and find enough food for all those hungry mouths. Different kinds of birds do these things in different ways. But they all face the same challenge: making sure that there’s a next generation of birds.

The More, the Merrier

The Gambel’s quail lives in the deserts of the American Southwest. These ground-dwelling birds usually lay 10 to 12 eggs at a time in a shallow nest. That’s a lot of tiny mouths to feed. 

Gambel’s quail chicks don’t need much attention. Just hours after hatching, they’re up and running. And they’d better be quick! These birds are a favorite prey of desert hunters like bobcats, snakes, and hawks. This means that only a few chicks will survive to be adults. By laying lots of eggs, adult quails increase the chances that at least some of their young will grow up to lay eggs themselves.

Try, Try Again

American robins are common backyard birds. They also lay many eggs — but not all at once. Instead, robins raise two to four batches of eggs over the summer. 

Robins build cup-shaped nests that hungry predators like snakes or raccoons can easily raid. Building several nests in a season instead of just once makes it more likely that at least one clutch will survive to become adult robins.

Spiny Hideaway

Many birds try to improve their eggs’ chances by hiding their nests. The Gila woodpecker has found a great hiding place — inside the giant saguaro cactus. This woodpecker drills a hole in the cactus, where she lays about six eggs. Not many egg-stealers are willing to risk being stuck by the sharp spines. 

Frosty Feet

Emperor penguins live on the ice sheets of Antarctica. They lay just one egg each year. The father penguin carries it on top of his feet, under a thick flap of feathery skin, for weeks while the mother penguin is away fishing. Once the chick hatches, they take turns bringing it meals of fish. The egg must never touch the icy ground, or it will freeze instantly. Caring for their eggs in this way allows the penguins to live where other birds can’t survive — but they only have room on their feet for one egg at a time.

Mother’s Helper

Nestled in the arms of the same saguaro cactus where the Gila woodpecker lives, you might see a huge bundle of sticks. This is the nest of the Harris’s hawk. Harris’s hawks raise two or three chicks a year, with help from the whole family. Young male hawks that don’t have mates yet will come back to help take care of their younger brothers and sisters.

The adult and teenage hawks hunt together in a pack. One or two will scare the prey from its hiding place. Then, another hawk swoops in from above! Working together means more food for the young in the nest. With the whole family pitching in, chicks stand a better chance. 

Fierce Family

Bald eagles are giant birds of prey. These beautiful hunters like to live by lakes or rivers, where they snatch fish from the water. Their massive stick nests can weigh up to 2,000 pounds (900 kg).

Like most large birds, bald eagles lay just two or three eggs each year. Once the eaglets hatch, they have a lot of growing to do, so they need a lot of food. Competition between young eagles can be fierce. Sometimes, if there is not enough food to go around, the weakest eaglet may not get any. It might even get pushed out of the nest. This seems harsh, but having fewer mouths to feed increases the chances that the other eaglets will grow up healthy.