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The bald eagle is the national bird of the United States. But 50 years ago, these eagles almost became extinct! Hunting and habitat destruction caused their numbers to fall. A dangerous pesticide called DDT harmed their eggs, making it less likely for chicks to hatch. Bald eagles were on the endangered species list from 1973 (the year the list started) until 2007.

Now, scientists have found that conservation efforts have paid off. Since 2009, the bald eagle population has quadrupled. That means it’s four times as great!