Tiger re-establishment potential to former Caspian tiger (Panthera tigris virgata) range in Central Asia

•Options to restore tigers to Central Asia are explored.•At least two habitat patches remain potentially suitable for tiger re-establishment.•The most promising site-the Ili-Balkhash-hosts ca. 7000 km2 of habitat.•The site could support a population of 64-98 tigers within 50 years.•Re-establishment of tigers in Central Asia may yet be tenable.

Caspian tigers (Panthera tigris virgata), a now extinct subspecies genetically similar to the Amur tiger (P. t. altaica), occurred until the mid-1900s from modern day Turkey and Iran east through Central Asia into northwest China. A literature analysis we conducted revealed that Caspian tigers occupied ca. 800,000-900,000 km2 historically, mostly within isolated patches of tugay- and reed-dominated riparian ecosystems at densities up to 2-3 tigers/100 km2. Herein we explored options to restore tigers to Central Asia using Amur tiger as an “analog” form. Spatial analyses based on remote sensing data indicated that options for Amur tiger introduction are limited in Central Asia but at least two habitat patches remain potentially suitable for tiger re-establishment, both in Kazakhstan, with a total area of < 20,000 km2. The most promising site-the Ili river delta and adjacent southern coast of Balkhash Lake-hosts ca. 7000 km2 of suitable habitat that our tiger-prey population models suggest could support a population of 64-98 tigers within 50 years if 40-55 tigers are translocated and current Ili river flow regimes are maintained. Re-establishment of tigers in Central Asia may yet be tenable if concerns of local communities in the Ili-Balkhash region are carefully addressed, prey population restoration precedes tiger introduction, Ili river water supplies remain stable, and the Amur tiger's phenotype proves adaptable to the arid conditions of the introduction site.