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pika


Flying Far Pikas can only climb so high. Frogs can only hop so far. Corals are stuck in place. So it’s easy to see why these animals can’t always escape the eff ects of climate change. Other animals can move more easily. Birds,


for instance, can fly far. Yet as the climate changes, many of them are in trouble, too. Red knots are a good example. Each spring, these birds leave Brazil. T ey


Search for a New Home Pikas already are losing their habitat. T ese small, furry mammals need the cold and ice to survive. In fact, if temperatures rise above 25°C, they can die. T at’s why they live next to mountain glaciers. Now, though, the ice is melting. Glaciers are


shrinking. To stay cool and survive, pikas must move. T ey’re leaving their dens and climbing mountains. Some whole populations of pikas have moved 150 m higher. It’s cooler there. Yet the pikas face new


problems. T eir habitat is shrinking. It’s more crowded. T ere’s less food to go around. All summer, pikas search for food. T ey


stuff tuſt s of grass in their cheeks. T ey snip flowers with their teeth. T ey scurry back to new dens. T ey’re trying to gather enough food and bedding to survive the winter. By summer’s end, the pikas are tired. Yet


they may not have enough food for the winter. Even if they do, biologists worry about their future. Pikas are too small to move far. T ey can’t climb down their mountain to find a cooler one. T ey can only go up. If the climate warms too much, pikas may run out of space.


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fly thousands of kilometers to beaches in the United States. T ere, they stop to rest. By then, the birds are tired, thin, and hungry. T ey dig their beaks into the sand to find food. T ey’re looking for fresh horseshoe crab eggs. For two weeks, the birds gobble eggs.


T ey double their weight. T ey’re ready to finish their flight to the Arctic.


Timing It Right For red knots, timing is everything. T ey must arrive at the beach when horseshoe crabs are laying eggs. T e timing must be just right. Climate change may mess up that timing.


Red knots migrate when the weather changes. A shiſt in weather patterns could cause them to leave too early or too late. T ey could miss the eggs. T en they would starve. T is shiſt is already changing the timing


of their trip back to Brazil. T ey arrive a week later than they used to. Now scientists are watching for changes


in their migration to the Arctic. It’s possible. Across the planet, other kinds of migrating birds are changing when they fly. Take ruby-throated hummingbirds, for


example. T ese tiny birds now arrive in North America nearly three weeks earlier than they used to. If the red knot changes its flight pattern that much, it could be disastrous.


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