By Susan Milius
Female toads that flirt with a male of another species may have their own best interests at heart.
The plains spadefoot toad spawns offspring that grow up faster if dad is a different species called the Mexican spadefoot, says Karin Pfennig of the University of North Carolina at Chapel Hill. The toads begin life as tadpoles in pools of water that can dry up quickly, so a little hop forward in speed of maturation can mean the difference between life and death. Pfennig has now found that in tough times, females tend to prefer Mexican males to plains males.