Saving endangered species is usually a matter of preserving habitat, fending off threats, and hoping for the best. Now, though, scientists at the University of Pennsylvania School of Veterinary Medicine have found a way to incubate sperm from other animals inside laboratory mice, a process they hope could aid species whose survival is threatened by the lack of sexually mature males. The technique could also be used to produce sperm from valuable farm animals before waiting for them to reach puberty; to help men with testicular problems have children; and to study reproductive cells. Philip Damiani of the Audubon Center for Research of Endangered Species said the development was an exciting one for species conservationists: “With endangered species, you lose some of the animals before they even reach puberty. Many pandas die right after birth. And if we can get testes material from them that’s going to be thrown in the garbage anyway, why not get the material to work with?”