Wildlife biologists helped the endangered peregrine falcon. They released young falcons in Acadia during the 1980's. Today, falcons successfully nest in Acadia on their own. In the spring, people watch nesting peregrines on Champlain Mountain.

Biologists also study coyote and red fox at Acadia. This red fox was released into the wild after it was given a check-up.

Scientist rangers monitor the health of Acadia's lakes by studying the animals that live in the lake. They also look at the chemistry of the water.