California condors have enormous wingspans. That's fine in the wilderness, but when a bird of this size encounters a power line, the results can be fatal. The San Diego Zoo Safari Park has a program to help train birds to avoid the hazard.
Jon Myatt/U.S. Fish and Wildlife Service/Flickr
The skull of a chicken embryo (left) has a recognizable beak. But when scientists block the expression of two particular genes, the embryo develops a rounded "snout" (center) that looks something like an alligator's skull (right).
Bhart-Anjan S. Bhullar
Recent research has shown that zebra finches sing differently when drunk, but not whether they know enough of the lyrics to get through "I Will Survive" or "Don't Stop Believin'."
Liza Gross/Courtesy Public Library of Science