The Herpetological Journal

Authors: Anh Van Pham, Truong Quang Nguyen, Cuong The Pham & Minh Duc Le

Abstract: The Lao sucker frog Amolops cremnobatus is known from Laos and Vietnam while the chloronate huia frog Odorrana chloronota has been recorded from Bangladesh, China, India, Laos, Myanmar, Thailand and Vietnam. However, the diet of the two species is still poorly understood. In this study, we investigate the diet composition and niche overlap in the two species living in sympatry at three streams in Vu Quang National Park, Ha Tinh Province, Vietnam. We use the stomach-flushing method to obtain the stomach contents of 83 individuals, including 51 of A. cremnobatus and 32 of O. chloronota. In total, 21 prey categories from 101 food items of invertebrates, and 18 prey categories from 103 food items of invertebrates are identified in the diet of A. cremnobatus and O. chloronota, respectively. Generally, A. cremnobatus consume more diverse prey types than those taken by O. chloronota, and beetles, cockroaches, grasshoppers and crickets represented the most important prey categories in both species. Our results also strongly corroborate the gape hypothesis by demonstrating that O. chloronata with a larger body size can ingest both larger prey items and greater food volumes. Furthermore, our findings show that body size and foraging behaviour play a significant role in selecting prey categories between the sympatric frog species.

Keywords: amphibian, gape hypothesis, niche overlap, prey types, stomach contents