title: Diet of the endangered big-headed turtlePlatysternon megacephalum.
abstract: Populations of the big-headed turtlePlatysternon megacephalumare declining at unprecedented rates across most of its distribution in Southeast Asia owing to unsustainable harvest for pet, food, and Chinese medicine markets. Research on Asian freshwater turtles becomes more challenging as populations decline and basic ecological information is needed to inform conservation efforts. We examined fecal samples collected fromP. megacephalumin five streams in Hong Kong to quantify the diet, and we compared the germination success of ingested and uningested seeds. Fruits, primarily ofMachilusspp., were most frequently consumed, followed by insects, plant matter, crabs and mollusks. The niche breadth of adults was wider than that of juveniles. Diet composition differed between sites, which may be attributable to the history of illegal trapping at some sites, which reduced the proportion of larger and older individuals. Digestion ofMachilusspp. fruits byP. megacephalumenhanced germination success of seeds by about 30%. However, most digested seeds are likely defecated in water in this highly aquatic species, which limits the potential benefit to dispersal. The results of our study can be used by conservation-related captive breeding programs to ensure a more optimal diet is provided to captiveP. megacephalum.
authors.affiliation: School of Biological Sciences, The University of Hong Kong, Hong Kong SAR, China; Department of Biology, Hong Kong Baptist University, Hong Kong SAR, China.
authors.forename: Yik-Hei
authors.initials: YH
authors.lastname: Sung
authors.affiliation: School of Biological Sciences, The University of Hong Kong , Hong Kong SAR , China.
authors.forename: Billy C H
authors.initials: BC
authors.lastname: Hau
authors.affiliation: School of Biological Sciences, The University of Hong Kong, Hong Kong SAR, China; Department of Natural Resources Science, University of Rhode Island, Kingston, RI, United States of America.
authors.forename: Nancy E
authors.initials: NE
authors.lastname: Karraker
keywords: Asian turtle crisis; China; Conservation; Foraging ecology; Functional ecology; Seed germination