Photo of the Day 20 February 2008

Leopard Seal, Antarctic Peninsula, Antarctica, 2006
Photograph by Paul Nicklen
A mature female leopard seal makes a threatening gesture to protect her kill from another leopard seal that had appeared behind the photographer. "More frightening than the canines," wrote the photographer, "was the deep jackhammer sound she let loose that rattled through my chest." Her display worked; the rival seal moved on.