Biogeography
Biogeography is the study of the geographical distribution of plants and animals.

Defining How Much of the World is Covered by Forests
With no universal definition, mapping and comparing forest coverage around the world is challenging.

Number of “Dees” in a Chickadee’s Alarm Call is Related to the Danger Level of Nearby Predators
The number of "dees" in a chickadee's alarm call correlates with the size and threat level of the predator.

Geography of Giant Sequoias
Giant sequoias are one of the longest lived tree species, with the oldest giant sequoia living an estimated 3,400 years.

Urbanization is Shortening the Legs of Western Fence Lizards
Western fence lizards have adapted to manmade surfaces in urban areas by developing shorter limbs and toes.

Most Abundant Landbird in the United States and Canada
The American robin has the largest population among all landbirds in the United States and Canada.