What's for dinner? Diet and potential trophic impact of an invasive anuran Hoplobatrachus tigerinus on the Andaman archipelago

• Published in: PeerJ (San Francisco, CA) Vol. 6; p. e5698
• Main Authors: Mohanty, Nitya Prakash, Measey, John
• Format: Journal Article
• Language: English
• Published: United States PeerJ, Inc 02.10.2018; PeerJ Inc
• Subjects: Birds; Competition; Diet; Diet overlap; Ecological niche; Ecology; Endemic species; Fejervarya; Food electivity; Freshwater Biology; Hoplobatrachus tigerinus; Introduced species; Invasions; Invasive impact; Islands; Limnonectes; Predation; Predator-prey; Predators; Prey; Reptiles & amphibians; Resource use; Taxonomy; Trends; Vertebrates; Zoology; Nepal; India; Anura; Predator-prey; Dicroglossidae; Ecological niche; Diet overlap; Food electivity; Invasive impact; Resource use
• ISSN: 2167-8359; 2167-8359
• DOI: 10.7717/peerj.5698

Amphibian invasions have considerable detrimental impacts on recipient ecosystems. However, reliable risk analysis of invasive amphibians still requires research on more non-native amphibian species. An invasive population of the Indian bullfrog, , is currently spreading on the Andaman archipelago and may have significant trophic impacts on native anurans through competition and predation. We carried out diet analyses of the invasive and native anurans, across four habitat types and two seasons; we hypothesized that (i) small vertebrates constitute a majority of the diet, particularly by volume and (ii) the diet of significantly overlaps with the diet of native anurans, thereby, leading to potential competition. We assessed the diet of the invasive (  = 358), and individuals of the genera (  = 375) and (  = 65) and found a significant dietary overlap of . with only . Small vertebrates, including several endemic species, constituted the majority of , diet by volume, suggesting potential impact by predation. Prey consumption and electivity of the three anurans indicated a positive relationship between predator-prey body sizes. Individuals of and chose evasive prey, suggesting that these two taxa are mostly ambush predators; individuals of Limnonectes chose a mixture of sedentary and evasive prey indicating that the species employs a combination of 'active search' and 'sit and wait' foraging strategies. All three species of anurans mostly consumed terrestrial prey. This intensive study on a genus of newly invasive amphibian contributes to knowledge of the impact of amphibian invasions and elucidates the feeding ecology of . , and species of the genera and . We also stress the necessity to evaluate prey availability and volume in future studies for meaningful insights into diet of amphibians.