It’s 8 p.m. on a dark and starry March evening at La Selva Research Station in Costa Rica. The air is warm and ... an Eyelash Viper, and even a three-toed sloth. The students, who spent seven days at ...

Sloths are notoriously hard to see and therefore can be hard to help. But one furry creature is at the heart of sloth conservation in Costa Rica ... upsid down in the rainforest canopy.