The density, ranging pattern and suitable habitat prediction of seabirds in the Northern Beibu Gulf, China

Abstract

The baseline information of density, distribution pattern of seabird community, and seabird-fishery interactions in the oceans are still relatively rare in China. From November 2013 to January 2014, we utilized line-transect method to investigate the bird community and fishery vessel in Beihai and Shatian, northern Beibu Gulf, China, for obtaining the baseline knowledge. The best model generated the seabirds’ density of 11.47 (95% confidence interval 6.90-19.05) individuals/km2 and 1.94 (1.27 - 2.95) individuals/ km2, respectively in Beihai and Shatian. The coefficient of variation value of 20.42% and 25.43% showed moderate accuracy. The Beihai and Shatian seabird communities had similar fixed kernel home range. Seabirds’ distribution largely overlapped with various vessels’ concentrated area, possibly due to abundant local fishery resources and forging behavior of seabirds. The MaxEnt model with the area under receiver operating curve (AUC) value of 0.957 for training data and 0.935 for test data showed reliable and accurate prediction. The distance to coast (64.7% contribution) and bathymetry (30.7% contribution) were the major variables. The model predicted extensive suitable coastal habitat of seabirds in northern Beibu Gulf. The present study provided valuable baseline information and a new perspective in protecting and monitoring seabirds.