Using Tracking Data to Identify Gaps in Knowledge and Conservation of the Critically Endangered Siberian Crane (Leucogeranus leucogeranus)

The critically endangered Siberian crane (Leucogeranus leucogeranus) is the world's third most endangered species of crane. Despite the enhanced conservation actions in recent years, there are pieces of evidence that suggest that its population is continuously decreasing. To gain insights into the possible causes of the population decline, we tracked nine Siberian cranes in Russia and Mongolia using GPS transmitters. We obtained migration episodes based on over 0.31 million subsequent locations from 3283 bird days between June 1995 and December 2021. Siberian cranes migrated an average of 5604 ± 362 km in spring from wintering to breeding areas and a mean of 5265 ± 454 km from breeding to wintering areas. We identified 35 staging sites along the migration corridor, including 17 critical staging sites at which birds staged for >14 days and 18 stopover sites that supported individuals for more than two days within a ca. 200 km-wide migratory corridor. Of the areas used by the tagged cranes, 77% of the breeding areas in Russia, 55% of the staging areas, 99% of the non-breeding summering area in Mongolia, and 50% of the wintering areas in Poyang Lake in China lay outside the current protected area network. Although we should be prudent about interpreting the conservation gaps of the entire population from only a few tracked birds, these results strongly suggest that the current protection network for this numerically rare species is inadequate, requiring urgent review.