T e flamingos have landed on a lake in Africa’s Great Riſt Valley. It’s one of several large, soda lakes scattered across the valley. T e source of these lakes’ salts and minerals


comes from lava and ash spewed by nearby volcanoes. T e lava hardens into rock and the ash settles on the ground. Where rain falls on the ground and streams rush over rocks, the water picks up the salts and minerals. It washes them into the lakes. T is changes the chemistry of the water. T ese salts and minerals can cause the water


in the lakes to fizz. T ey’re so caustic that they can burn skin and chew holes in metals. Few organisms can survive in many of these lakes. Yet there is a living thing, or biotic factor,


that thrives here. It’s a kind of alga. T e algae grow when the temperature and the amount of minerals and light are just right. T e mix of


these abiotic factors, or nonliving things, make the algae bloom, or grow rapidly. T e bloom covers the lake, turning it blue-green.


When the algae bloom, the flamingos arrive. Soon, it’s clear why. T ey’ve come to eat. T ousands of birds stand ankle deep in the


water. Each flamingo dips its long neck toward the water. With its head almost upside down, it swishes its curved bill from side to side. T e bird’s bill skims the top of the water. Its


thick tongue pumps water into its bill. T en it squeezes the water through filters inside its bill. T ese filters trap algae. T e flamingo quickly squirts out the water and swallows the algae. Few other animals eat this algae. T at means


the flamingos have little competition for food. T ey swallow it as fast as they can scoop it up. A flock of 100,000 birds can gobble as much as 32 metric tons of algae a day!


Fun Fact: Red pigments in the algae that fl amingos eat turn their feathers rosy pink and their eyes bright red.


NOVEMBER–DECEMBER 2014 5


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24