In 1978, renowned ecologist Dan Janzen jumped into a ravine in Costa Rica, broke three ribs, and spent the first month of the rainy season watching the tropical dry forest from inside a shack. At night, a simple 25-watt bulb drew in so many moths that they plastered the walls like a live wallpaper. The forest teemed with caterpillars, so many that whole trees stood defoliated and the ground lay carpeted in their droppings. “There has never been such a high-density caterpillar year since then,” Janzen told Mongabay about Costa Rica’s Guanacaste Conservation Area. “And there has been a continual decline after.” That decline represents more than just the global phenomenon of insect decline. It signals the quiet collapse of one of Earth’s most overlooked and endangered ecosystems: tropical dry forests. These forests once dominated vast swaths of the planet, but after decades of development and now accelerating climate change, what remains is dwindling and lacks protection. The forgotten half of tropical forests Stretching across Latin America, Africa, Asia and the Pacific — from Madagascar’s thorny forests to Brazil’s Caatinga, from South America’s Chaco to India’s seasonal woodlands — tropical dry forests account for nearly half of all tropical and subtropical forests worldwide. The scale is staggering. Up to 60% of all forests in India and approximately 30% of the forests in mainland Southeast Asia are classified as dry forests. In southern Africa, the miombo woodlands alone contribute to the livelihoods of more than 100 million people. Miombo woodlands in…This article was originally published on Mongabay