Wild Alaska

Photos ranging from Lake Clark NP to the Arctic Circle

With the introduction of DDT as a widespread insecticide in the United States in 1940, the bald eagle population decreased radically, falling to a low point of 487 nesting pairs in 1963. The DDT alters the calcium metabolism of female birds, preventing them from creating a hard shell around the eggs they produce. The egg thinning led to a higher rate of egg loss due to cracks during incubation.

10 / 62

With the introduction of DDT as a widespread insecticide in the United States in 1940, the bald eagle population decreased radically, falling to a low point of 487 nesting pairs in 1963. The DDT alters the calcium metabolism of female birds, preventing them from creating a hard shell around the eggs they produce. The egg thinning led to a higher rate of egg loss due to cracks during incubation.