Zoological Studies

Vol. 57, 2018

(update: 2018.01.17; 01.25)

Seasonal, Lunar and Tidal Influences on Habitat Use of Indo-Pacific Humpback Dolphins in Beibu Gulf, China

Shanshan Li1, Huili Gao1, Xiuqing Hao1, Lin Zhu1, Ting Li1, Hongke Zhang2, Yi Zhou2, Xinrong Xu1, Guang Yang1, and Bingyao Chen1,*

1Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing 210023, China
2National Hepu Dugong Nature Reserve administration station, 49 Gongyuan Road, Beihai, China

(Received 23 January 2017; Accepted 22 December 2017; Published 25 January 2018; Communicated by Benny K.K. Chan)

Shanshan Li, Huili Gao, Xiuqing Hao, Lin Zhu, Ting Li, Hongke Zhang, Yi Zhou, Xinrong Xu, Guang Yang, and Bingyao Chen (2018) Cetacean habitat use based on different environmental phases varies between species and geographies, and little is known about Pacific humpback dolphin habitat use in the Beibu Gulf. Here we aimed to identify seasonal, lunar and tidal influences on the spatial use of Beibu humpback dolphins based on two parameters: water depth and distance to an estuary. The ANOVA test indicated that habitat use was influenced by seasons and tidal phases, but not lunar phases. The humpback dolphins utilized shallow areas near an estuary throughout the wet season and high tides, and moved toward deeper water during the dry season and low tides. This habitat preference is likely synchronized with prey seasonal and tidal movements. The wet season and high tides bring abundant prey resources and increase accessibility to inshore shallow waters for humpback dolphins. The present study provides new information on regular habitat use by Indo-Pacific humpback dolphins, which is crucial for developing effective conservation strategies.

Key words: Beibu Gulf, Habitat use, Indo-Pacific humpback dolphins, Seasonal distribution, Tidal influence.

*Correspondence: E-mail: bychen@njnu.edu.cn