The growing consensus that the earth is in the throes of a sixth mass extinction has focused attention on a centuries-old ecological puzzle: why do species suddenly disappear by the droves? Madagascar could hold some lessons, but scientists are still debating what happened there. The vast tropical island in the southwest Indian Ocean experienced a megafauna crash relatively recently, about 1,000 years ago. Yet we still do not know for sure what doomed the gorilla-sized lemurs, towering elephant birds, and grand tortoises that once roamed the island. Humans and climatic changes are scientists’ favored culprits when explaining megafaunal collapses worldwide, especially since human arrival on islands has almost always ushered in dramatic biodiversity losses. But disentangling the importance of each is still a ripe area for research. A recently published paper in the journal Science Advances complicates the widely held understanding that humans in Madagascar were solely to blame, by drawing attention to climatic disruptions. The authors constructed a climatic record spanning 8,000 years. During this period, the island’s inhabitants experienced several stretches of arid conditions. Madagascar was in the grips of one such megadrought when megafaunal extinctions swept the island, their analysis shows. A map showing Madagascar on the left and Rodrigues on the extreme right. “Whether you look in Mauritius, Rodrigues, or Madagascar, we have records of megafauna surviving right through all those climate changes,” said study co-author Ashish Sinha, a climate scientist at California State University, Dominguez Hills. “So, the question is, why do they not survive…This article was originally published on Mongabay Läs mer