Read J.,Arid Recovery |
Read J.,University of Adelaide |
Eldridge S.,Environment and the Arts
Rangeland Journal | Year: 2010
A single procedure that land managers can readily use to simultaneously monitor populations of multiple pest animal species would enhance capacity to effectively manage environmental impacts in the Australian rangelands. Such a procedure should be efficient and provide a standard for data collection, enabling meaningful evaluation of changes through time. This study compared the efficiency of two indices, namely spotlight counts and a variety of passive activity indices, for detecting rabbit, cat, fox and dingo activity. Spotlight counts were more practical for estimating rabbit activity but were poor indicators of cat, fox or dingo activity. Records of animal tracks on discrete 200m dirt road segments with favourable substrate and separated by at least 2km are considered optimal for collectively monitoring relative changes through time in rabbit, cat, fox and dingo activity. © Australian Rangeland Society 2010.
Smith J.G.,Charles Darwin University |
Griffiths A.D.,Environment and the Arts |
Brook B.W.,University of Adelaide
Population Ecology | Year: 2010
The population dynamics of varanids (large monitor lizards) is poorly understood. We report on the most detailed study to date of a population of one of Australia's largest semi-aquatic varanids, Varanus mertensi. Survival of V. mertensi was derived from known-fate modelling of radio-tracked individuals over two and a half years. We demonstrate empirically what intuition suggests; that apparent survival probability in long-lived lizards is high over short sampling periods, with body size and gender influencing these estimates. Survival estimation in long-lived species such as varanids clearly requires long-term studies. © The Society of Population Ecology and Springer 2009.
Schmid M.,Helmholtz Center for Environmental Research |
Rothballer M.,Helmholtz Center for Environmental Research |
Hill J.,Environment and the Arts |
Tuanyok A.,Northern Arizona University |
And 2 more authors.
Environmental Microbiology | Year: 2012
Melioidosis is an emerging infectious disease of humans and animals in the tropics caused by the soil bacterium Burkholderia pseudomallei. Despite high fatality rates, the ecology of B. pseudomallei remains unclear. We used a combination of field and laboratory studies to investigate B. pseudomallei colonization of native and exotic grasses in northern Australia. Multivariable and spatial analyses were performed to determine significant predictors for B. pseudomallei occurrence in plants and soil collected longitudinally from field sites. In plant inoculation experiments, the impact of B. pseudomallei upon these grasses was studied and the bacterial load semi-quantified. Fluorescence in situ hybridization and confocal laser scanning microscopy were performed to localize the bacteria in plants. Burkholderia pseudomallei was found to inhabit not only the rhizosphere and roots but also aerial parts of specific grasses. This raises questions about the potential spread of B. pseudomallei by grazing animals whose droppings were found to be positive for these bacteria. In particular, B. pseudomallei readily colonized exotic grasses introduced to Australia for pasture. The ongoing spread of these introduced grasses creates new habitats suitable for B. pseudomallei survival and may be an important factor in the evolving epidemiology of melioidosis seen both in northern Australia and elsewhere globally. © 2011 Society for Applied Microbiology and Blackwell Publishing Ltd.
Tsai C.-C.,Kaohsiung District Agricultural Research and Extension Station |
Tsai C.-C.,National Pingtung University of Science and Technology |
Li S.-J.,Kaohsiung District Agricultural Research and Extension Station |
Su Y.-Y.,Kaohsiung District Agricultural Research and Extension Station |
And 10 more authors.
Biochemical Systematics and Ecology | Year: 2012
Ceriops (Rhizophoraceae) is a genus comprised of five species of mangroves distributed in tropical and subtropical coastal regions. In this study, sequences from nuclear ribosomal ITS and the plastid . trnL intron are used to construct molecular phylogenies of this genus revealing two species complexes, the . C. . tagal complex (. C. tagal and . C. . australis), and the . C. . decandra complex (. C. decandra, . C. . pseudodecandra and . C. . zippeliana), each forming a distinct clade. All five species, including the newly designated species . C. pseudodecandra, are well supported. However, natural hybridization and historical introgression between . Ceriops species are also demonstrated. The ITS sequences of . Ceriops species, in contrast to their plastid . trnL intron sequences, show a great amount of homoplasy during evolution. Historical introgression originating from natural hybridization was demonstrated based on the additivity of ITS sequences from putative parents. Of the five . Ceriops species, . C. pseudodecandra is a relatively isolated species. . C. decandra and . C. zippeliana show mutual introgression in most populations. According to both the nuclear ITS sequences and the plastid . trnL intron, an intermediate form from Darwin is likely a natural hybrid, with . C. tagal and . C. australis respectively the maternal and paternal parents. © 2012 Elsevier Ltd.
Ward L.,Royal Darwin Hospital |
Karp D.,Environment and the Arts |
Jolly P.,Environment and the Arts |
Godoy D.,Imperial College London |
And 2 more authors.
Emerging Infectious Diseases | Year: 2011
To determine whether unchlorinated bore water in northern Australia contained Burkholderia pseudomallei organisms, we sampled 55 bores; 18 (33%) were culture positive. Multilocus sequence typing identified 15 sequence types. The B. pseudomallei sequence type from 1 water sample matched a clinical isolate from a resident with melioidosis on the same property.
Draper A.D.K.,Charles Darwin University |
Mayo M.,Charles Darwin University |
Harrington G.,Charles Darwin University |
Karp D.,Environment and the Arts |
And 5 more authors.
Applied and Environmental Microbiology | Year: 2010
We analyzed water parameters and the occurrence of the melioidosis agent Burkholderia pseudomallei in 47 water bores in Northern Australia. B. pseudomallei was associated with soft, acidic bore water of low salinity but high iron levels. This finding aids in identifying water supplies at risk of contamination with this pathogenic bacterium. Copyright © 2010, American Society for Microbiology. All Rights Reserved.
Milne D.J.,Environment and the Arts |
Pavey C.R.,Environment and the Arts
Australian Zoologist | Year: 2011
The Northern Territory has 36 species of bats including three fruit-bats. For each species we provide a distribution map as well as descriptions of their ecology that is relevant to their conservation and management. With one exception (Hipposideros diadema inornatus), all bat species have relatively broad distributions and species diversity is higher in the northern wet-dry tropics compared to the southern arid zone.Three species, Saccolaimus saccolaimus, Macroderma gigas and H. d. inornatus, are listed as threatened and a further three species, Taphozous kapalgensis, H.stenotis and Rhinonicteris aurantius, have been listed as near threatened under Territory, National and/or International legislative and conservation listings. Since European settlement, no bat species are thought to have become extinct, although there is little historical data available to confirm this pattern. M. gigas has undergone a significant decline in range in recent years, but is currently regarded as secure. H. d. inornatus has also suffered a localised extinction, but is also regarded as secure. There are indications that H.stenotis may be declining and is in need of further assessment. The main recommendations for the future conservation management of bats in the Northern Territory include: targeted surveys for priority species; general surveys of poorly known areas; establishment of longer-term monitoring programs; further autecological research, particularly for the more common species; and further research to assess the importance of riparian zones as areas of conservation significance for bats.