Inadvertent climate refugia

For centuries, humans have intentionally moved species around the world, and such actions have rarely been laudable from conservation perspectives. The notion that introduced populations of cold-adapted species hold conservation value despite their non-native status remains controversial. Many such populations exist as a legacy of humans moving wildlife to novel environments with little true consideration of species conservation. Herein, we identify cases in which individuals from inadvertent climate refugia (ICR) are returned to formerly occupied ranges or used to augment declining native populations. While conservation benefits have been infrequently realized, the global distribution of ICR offers a potentially untapped resource. Lessening biodiversity loss under increasing climate challenges will likely require assisted migration of many species and necessitate novel valuation of extant introduced populations—such as those within ICR. While ecological costs of translocated species are widely known, we highlight how species moved generations ago to ICR offer a reservoir for reintroductions and a buffer against rapidly changing climates.