Mr. Mom. The male Darwin frog goes to extraordinary length to nurture his growing young. After the female lays eggs in leaf litter, he fertilizes them and patiently remains nearby for about 20 days. he then picks up the tadpoles or embryos about to hatch and maneuvers them into his vocal sac, where they continue to develop. After some 50 to 70 days, juvinile frogs emerge from the males mouth. This unusual amphibian, first collected by Charles Darwin during his famous voyage, has the ability to play dead when threatened. But the fatal forces of habitat loss and disease that afflict it today are all too real.