Migration Bottlenecks, Climate, and the Conservation of Pleistocene Relicts in Central Asia

摘要: Land bridges once assured transcontinental connectivity, but climate-induced habitat loss resulted in the extinc- tion of numerous North American large mammals. Using GPS technology on formerly widespread now endan- gered saiga Mongolia, we identified a fine-scaled 5-km wide critical corridor, whose protection is for maintain- ing migration and meta-population structure. The world's great overland migrations are disappearing, truncating fundamental processes that have contributed to ecosystem functioning millennia. With more people reli- ant lands were remote, intact habitats replaced by livestock, fences, (1). Nevertheless, expansive grasslands deserts China, Ka- zakhstan, Russia still sustain extraordinary movements between winter summer ranges, including those chiru (Pantholops hodgsonii), white-(Procapra gutturosa) black-tailed (Gazella subgutturosa) gazelles, khulan (Equus hemionus), (Saiga tatarica), Bactrian camels (Camelus bactrianus) (2 - 4). latter three species all recognized as endangered IUCN along with mam- moths, Panthera lions, wild horses spp.) moved Asia America using Bering Bridge. That conduit inter-continental movement collapsed during Late Pleistocene when climate changed, ocean levels rose, arid Mammoth Steppe Beringea disappeared (5). Although saiga, camels, dependent upon these cold-adapted xeric grasslands, such remnant their associated fauna currently persist situ only Central While Being Bridge enabled connectivity across broad landscapes, today's conservation challenges appropriately linked maintenance among population subunits, protecting corridors at fine scale, understanding direct impacts humans under an umbrella change. Long-term fragmented populations requires meta- above little-known relicts re- stricted Asia, challenge has been ac- quisition knowledge, not about routes, if any, land(s) sustaining disjunct segments (6).