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Zarzoso-Lacoste D, Bonnaud E, Corse E, Dubut V, Lorvelec O, De Meringo H, Santelli C, Meunier JY, Ghestemme T, Gouni A, Vidal E. Stuck amongst introduced species: Trophic ecology reveals complex relationships between the critically endangered Niau kingfisher and introduced predators, competitors and prey. NEOBIOTA 2019. [DOI: 10.3897/neobiota.53.35086] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The introduction of mammals on oceanic islands currently threatens or has caused the extinction of many endemic species. Cats and rats represent the major threat for 40 % of currently endangered island bird species. Direct (predation) and/or indirect (exploitative competition for food resource) trophic interactions are key mechanisms by which invaders cause the decrease or extinction of native populations. Here, we investigated both direct and indirect trophic interactions amongst four predator species (i.e. animals that hunt, kill and feed on other animals), including three introduced mammals (Felis silvestris catus, Rattus rattus and Rattus exulans) and one critically endangered native bird, the Niau kingfisher (Todiramphus gertrudae). All four species’ diets and prey availability were assessed from sampling at the six main kingfisher habitats on Niau Island during the breeding season. Diet analyses were conducted on 578 cat scats, 295 rat digestive tracts (218 R. exulans and 77 R. rattus) and 186 kingfisher pellets. Despite simultaneous use of morphological and PCR-based methods, no bird remains in cat and rat diet samples could be assigned to the Niau kingfisher, weakening the hypothesis of current intense predation pressure. However, we determined that Niau kingfishers mainly feed on introduced and/or cryptogenic prey and highlighted the potential for exploitative competition between this bird and both introduced rat species (for Dictyoptera, Coleoptera and Scincidae). We recommend removing the cats and both rat species, at least within kingfisher breeding and foraging areas (e.g. mechanical or chemical control, cat sterilisation, biosecurity reinforcement), to simultaneously decrease predation risk, increase key prey availability and boost kingfisher population dynamics.
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Reilly SB, Stubbs AL, Karin BR, Arida E, Iskandar DT, McGuire JA. Recent colonization and expansion through the Lesser Sundas by seven amphibian and reptile species. ZOOL SCR 2019. [DOI: 10.1111/zsc.12368] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Sean B. Reilly
- Museum of Vertebrate Zoology, Department of Integrative Biology University of California Berkeley California USA
| | - Alexander L. Stubbs
- Museum of Vertebrate Zoology, Department of Integrative Biology University of California Berkeley California USA
| | - Benjamin R. Karin
- Museum of Vertebrate Zoology, Department of Integrative Biology University of California Berkeley California USA
| | - Evy Arida
- Museum Zoologicum Bogoriense Indonesian Institute of Sciences (LIPI) Cibinong Indonesia
| | - Djoko T. Iskandar
- School of Life Sciences and Technology Institut Teknologi Bandung Bandung Indonesia
| | - Jimmy A. McGuire
- Museum of Vertebrate Zoology, Department of Integrative Biology University of California Berkeley California USA
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Eckstut ME, Hamilton AM, Austin CC. Variable Unisexuals and Uniform Bisexuals: Morphology, Genetics, and Biogeography of theNactus pelagicusComplex on Tanna Island, Vanuatu. HERPETOLOGICA 2013. [DOI: 10.1655/herpetologica-d-11-00089] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Zug GR. A new species of treeskink (Squamata: Scincidae: Emoia samoensis species group) from Rotuma, south-central Pacific. P BIOL SOC WASH 2012. [DOI: 10.2988/11-24.1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
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