by Ellen Lambeth
Next time your mom complains about your picky eating habits, tell her this: Some animals do just fine on only one kind of food. You could point out the giant panda of China in the photo above, for example. Pandas eat bamboo and not much else.
Your plan could backfire, though. What if you ran out of your favorite food? Could you survive without it? If something were to happen to China's bamboo forests, pandas would be totally out of luck. They evolved to survive on one kind of food and couldn't easily switch to another. That's one reason that, like pandas, many picky eaters become endangered as their food sources disappear.
LEGGO MY EGGO
As its name suggests, an African egg-eating snake eats only eggs—bird eggs, to be exact. The series of photos above shows how it swallows an egg way bigger than its own head!
As you can see, the snake first has to wrap its mouth around its meal. It can do this because it has extremely flexible jaws. It also has a throat that expands as the egg makes its way down. What happens next? The snake flexes its neck, weaving it from side to side. That makes a row of bony points on the underside of the snake's spine crack the egg open. By squeezing its neck muscles, the snake squirts the egg's innards down to its stomach. Then it spits out the crushed shell. Urp!
SOUP OF THE SEA
Can you believe that the biggest animal on Earth eats one of the smallest creatures in the sea? That would be the blue whale feeding almost entirely on tiny shrimp-like-creatures called krill. To make that work, of course, the whale has to eat gobs of krill—up to 40 million a day! After all, a blue whale can be 100 feet long while a single krill (photo 1) may measure less than an inch.
Fortunately for blue whales, krill live in huge bunches like the one in photo 2. The whale lunges at a bunch with jaws open wide. Its throat expands to take in a huge mouthful of krill and water. Then the whale closes its mouth and pushes the water out with its tongue trapping the krill inside (photo 3).
The butterfly above is a monarch, sipping nectar from a milkweed flower. Monarchs sip from many kinds of flowers, but they almost always lay their eggs on milkweeds. That's because milkweed leaves are the food of choice for the caterpillars that come from the eggs (middle photo).
The plant's milky sap has a chemical that becomes part of a growing caterpillar's body. The chemical makes the insect taste terrible to predators such as birds. The caterpillar's yellow and black stripes are a warning: "Bite me and you'll be sorry!"
Orange and black are warning colors, too. Even after the caterpillar turns into a butterfly, the insect remains protected by the toxic meals it ate while growing up.
SNAILS, TO GO!
Most big birds of prey go for meaty meals such as rodents, lizards, fish or small birds. But the snail kite usually prefers to dine on the same odd thing, day after day: apple snails. As you can see (top right photo) it just grabs and goes!
The endangered kites need big, open marshes such as the Florida Everglades to find their food. Over the years, though, problems in these wetlands have caused many of the snails—and the kites—to disappear.
The black-footed ferret (above right) is a big fan of the prairie dog (small photo). That's because ferrets are right at home in prairie dog burrows and most of their diet is prairie dogs.
Trouble is, lots of prairie dogs got wiped out when settlers turned prairies into ranches. Because of that, the ferret nearly went extinct as well. Now, scientists are working hard to help both creatures make a comeback.
Remember: Being a picky eater works only when you can survive on what you pick—AND there's enough of it around.