In certain mountaintop cloud forests in Oaxaca, Mexico, this swallowtail butterfly is a rare, glorious sight. The undersides of its wings, shown here, glow with pattern and color—perhaps drawing in potential mates. Atop the wings is a simpler pattern—possibly providing a bit of camouflage.

Today, though, the species is endangered. Wet, cool cloud forest ecosystems harbor many rare species; the isolated environment acts like an island, with the lowland forest serving as a hot, dry barrier. As a result, even small changes to the butterflies’ environment could leave them with nowhere to go. But climate change threatens Mexico’s cloud forests, which have already been fragmented, due to logging, ranching and farming. To stem the losses, people living in neighboring communities have started to manage forests for biodiversity. In some places, they communally own large tracts of land, where they have prohibited butterfly collection and closely monitor the health of the forests.