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Higher extinction rates of dasyurids on A ustralo‐ P apuan continental shelf islands and the zoogeography of N ew G uinea mammals
Author(s) -
Lavery Tyrone H.,
Fisher Diana O.,
Flannery Tim F.,
Leung Luke K.P.
Publication year - 2013
Publication title -
journal of biogeography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.7
H-Index - 158
eISSN - 1365-2699
pISSN - 0305-0270
DOI - 10.1111/jbi.12072
Subject(s) - geography , ecology , species richness , population , persistence (discontinuity) , extinction (optical mineralogy) , continental shelf , biogeography , global biodiversity , biology , biodiversity , demography , fishery , geology , paleontology , geotechnical engineering , sociology
Aim Contemporary patterns of mammalian species richness on islands are influenced by well‐understood biogeographical variables. Whether or not mammalian orders differ in their rates of persistence, however, remains uncertain. Our aims were to assess the persistence of four mammalian orders on A ustralo‐ P apuan continental shelf islands in relation to the faunas within adjacent zoogeographic provinces. We also aimed to define N ew G uinea's mammalian zoogeographic provinces quantitatively. Location New G uinea and 274 A ustralo‐ P apuan continental shelf islands. Methods We compiled 4194 distributional records for 264 of N ew G uinea's native mammals. Records were allocated to existing mapped bioregions. We used cluster analysis to allocate bioregions to zoogeographic provinces. Using generalized linear models, we determined the persistence of insular mammals as proportions of the species present within adjacent zoogeographic provinces. Persistence rates were calculated for four major orders ( D asyuromorphia, D iprotodontia, P eramelemorphia and R odentia). Results The classification dendrogram grouped N ew G uinea's bioregions into three areas corresponding to the O ceanic, T umbanan and A ustral provinces. In all but two zoogeographic provinces, the proportions of D asyuromorphia persisting on islands were lower than other orders. Overall, species of D asyuromorphia were much less likely to persist on A ustralo‐Papuan continental shelf islands. Main conclusions Unlike the other orders considered, dasyuromorphs are carnivorous and insectivorous and require large home ranges relative to body size. We suggest that the resulting low population densities might expose species in this order to higher rates of extinction on islands. Translocations of threatened mammals to predator‐free islands are common, but our results suggest that insurance populations of threatened dasyurids on small islands may be less secure than translocations of other taxa. Our results support calls for insurance populations of the rapidly declining dasyurid, the T asmanian devil ( S arcophilus harrisii ), to be established on mainland Australia rather than on islands alone.