Genetic structure and population history of wintering Asian Great Bustard (Otis tarda dybowskii) in China: implications for conservation

Wintering areas affect population processes and genetic structuring of many bird species. The Asian Great Bustard (Otis tarda dybowskii) is declining across its range as its breeding and wintering grounds become more fragmented. No genetic information for this vulnerable subspecies in the wild exists. We used noninvasive fecal sampling and mitochondrial sequencing to quantify the level of genetic diversity and the extent of genetic differentiation within and among the wintering populations. Bayesian skyline plot (BSP) analysis was conducted to assess changes in population size over the last several thousand years. Overall, 17 haplotypes were identified in 101 individuals from six wintering grounds, with mean haplotype diversity of 0.90 ± 0.02. Significant population differentiation among wintering grounds was observed [population pairwise test (ΦST) = 0.13, p < 0.001], with genetic differentiation associated with geographical distance (R2 = 0.26, p < 0.05) and pairwise tests consistent with some degree of population admixture. The BSP exhibited a gradual increase in effective population size beginning around 28,000 years ago, but a decrease starting approximately 4000 years ago. Given that China has the most important wintering grounds for the Asian Great Bustard, and that these are becoming increasingly fragmented, it is likely necessary to establish more protected areas to facilitate the protection and monitoring of wintering Great Bustards.