In the forest in Mandena, Madagascar, banana-leafed Ravenala trees crowd out the sun, their electric blue seed pods dotting the leaf litter and white sand below. When night falls, gray mouse lemurs emerge from tree hollow dens to feed on insects, flowers and fruit. During the rainy season, pools of water form where screw pines’ pom-pom-like clusters of long leaves meet their trunks, the base of each leaf forming a reservoir just large enough to nurture small schools of tadpoles to maturity before the puddles dry out every April. There ring-wearing tree frogs—named for the bright-white bands that mark each webby finger—find a perfect spot to nurture their next generation, high above would-be predators. Leopard-spotted and no bigger than a child’s thumb, the frogs lay their eggs in a sticky clutch above the water and stand watch for nearly a week, until their offspring drop into the tiny pool and begin to swim.