Esau’s journey spans borders that elephants cannot see — but must obey. His fate reflects the growing challenges facing elephants across Africa.

In a vast stretch of the Sonoran Desert, between the towns of San Luis Río Colorado and Sonoyta in northern Mexico, sits a modest building of cement, galvanized sheet metal, and wood—the only stop ...

For centuries, borders have been central to salmon management customs on the Salish Sea, but how those borders were drawn has had very different effects on the Northwest salmon fishery. Native peoples ...