High genetic diversity and absence of phylogeographic structure in breeding populations of vulnerable Saundersilarus saundersi (Charadriiformes: Laridae) in Bohai Bay, China.

Genetic diversity is an important consideration in developing effective conservation strategies for threatened species. The Saunders's Gull ( Saundersilarus saundersi) is a globally vulnerable species, which breeds in coastal wetlands in eastern China and western South Korea. Approximately 85% of the world population breeds at three sites along Bohai Bay in eastern China: Nanxiaohe in Liaohekou National Nature Reserve of Liaoning Province, and Yiqianer and Dawenliu in Yellow River Delta National Nature Reserve of Shandong Province. We examined mitochondrial and nuclear markers to detect genetic diversity and phylogeographic structure of the three Bohai Bay subpopulations. Unexpectedly high genetic diversity was observed in both mitochondrial and nuclear markers for every subpopulation. There was no evidence of phylogeographic structure among the three breeding subpopulations, indicating high levels of gene flow in the recent past, possibly continuing into the present day. These results reveal high levels of genetic diversity and evolutionary potential among the current populations of S. saundersi in Bohai Bay. If timely conservation measures are implemented, this gull species would has excellent prospects for long-term survival. [ABSTRACT FROM AUTHOR]