The first fall runs of chinook salmon since the project in California and Oregon was completed have surpassed researchers’ expectations.

Traditionally found in warm climates, like the American Southwest, armadillos have been migrating farther and farther north, researchers say.

© Aaron Ambos

Birds are drawn to lights, and more than a billion die each year after crashing into buildings, experts said.

© Maddie McGarvey for The New York Times