On the Air: April 19, 2015
Oystercatchers are devoted parents. Credit: National Oceanic and Atmospheric Administration

The American oystercatcher is a brawny shorebird. An adult stands about a foot-and-a-half tall and has a wingspan of up to three feet. Yet the oystercatcher is also among the most devoted of parents.

In Print: April 1, 2015
Almost one million years ago, North Atlantic currents and northern hemisphere ice sheets underwent changes. Credit: NASA

Just under a million years ago, a major pattern in Earth’s climate suddenly changed. Instead of having an ice age about every 41,000 years, the cycle switched to about every 100,000 years – and the cold periods had even lower average temperatures than the previous ones. What caused the interval between ice ages to double?