|Gordon et al.||2017||Shrub encroachment is linked to extirpation of an apex predator||
Abstract The abundance of shrubs has increased throughout Earth's arid lands. This ‘shrub encroachment’ has been linked to livestock grazing, fire-suppression and elevated atmospheric CO2 concentrations facilitating shrub recruitment. Apex predators initiate trophic cascades which can influence the abundance of many species across multiple trophic levels within ecosystems. Extirpation of apex predators is linked inextricably to pastoralism, but has not been considered as a factor contributing to shrub encroachment. Here, we ask if trophic cascades triggered by the extirpation of Australia's largest terrestrial predator, the dingo (Canis dingo), could be a driver of shrub encroachment in the Strzelecki Desert, Australia. We use aerial photographs spanning a 51-year period to compare shrub cover between areas where dingoes are historically rare and common. We then quantify contemporary patterns of shrub, shrub seedling and mammal abundances, and use structural equation modelling to compare competing trophic cascade hypotheses to explain how dingoes could influence shrub recruitment. Finally, we track the fate of seedlings of an encroaching shrub, hopbush (Dodonaea viscosa angustissima), during a period optimal for seedling recruitment, and quantify removal rates of hopbush seeds by rodents from enriched seed patches. Shrub cover was 26–48% greater in areas where dingoes were rare than common. Our structural equation modelling supported the hypothesis that dingo removal facilitates shrub encroachment by triggering a four level trophic cascade. According to this model, increased mesopredator abundance in the absence of dingoes results in suppressed abundance of consumers of shrub seeds and seedlings, rodents and rabbits respectively. In turn, suppressed abundances of rodents and rabbits in the absence of dingoes relaxed a recruitment bottleneck for shrubs. The results of our SEM were supported by results showing that rates of hopbush seedling survival and seed removal were 1·7 times greater and 2·1 times lower in areas where dingoes were rare than common. Our study provides evidence linking the suppression of an apex predator to the historic encroachment of shrubs. We contend that trophic cascades induced by apex predator extirpation may be an overlooked driver of shrub encroachment.
Check out the cartoon! https://kapowecology.wordpress.com/2017/01/20/dingoes-run-the-show-right-down-to-the-shrubs/
|Kingsford||2017||Submission on proposed Basin Plan amendments for the Northern Basin||
Scientific evidence supports an increase in environmental flows to achieve sustainability for the environmental assets of the Northern Basin and the Murray-Darling Basin, beyond the 390GLs per year. The proposed reduction of 70 GL per year will continue to drive ongoing degradation of northern basin environmental values and ecosystem services provided by rivers, requiring future adjustments to provide more water for the rivers, particularly with the increasing effects of climate change of increasing temperatures and potential changes to run-off. This submission identifies eight major concerns which clearly show there is insufficient evidence for a recommendation to reduce the environmental flow target of the Northern Basin of the Murray-Darling Basin. The submission provides 10 reasons for supporting this position of rejecting the recommendations for reductions in water recovery.
|Parr et al||2016||Cranial Shape and the Modularity of Hybridization in Dingoes and Dogs; Hybridization Does Not Spell the End for Native Morphology||
Read the full publication here
|Clarke-Wood et al.||2016||The ecological response of insectivorous bats to coastal lagoon degradation||
Coastal lagoons provide key habitat for a wide range of biota but are often degraded by intense urbanization pressures. Insectivorous bats use these highly productive ecosystems and are likely to be impacted by their decline in quality. We compared bat activity and richness and invertebrate biomass and richness across a gradient of lagoon quality (9 lagoons) in the Greater Sydney region, Australia to determine the extent to which bats and their prey were impacted by lagoon degradation. Bats were more diverse and 19 times more active at higher quality lagoons. The trawling bat, Myotis macropus, was absent from all low quality lagoons, but these lagoons were used by other species such as Miniopterus schreibersii oceanensis. Invertebrate richness and biomass did not differ significantly across lagoon quality. We examined potential mechanisms of insectivorous bat decline at degraded lagoons by measuring toxic metal concentrations in bat fur, invertebrates and sediment. Lead and zinc were detected at environmentally significant levels in the sediments of lower quality lagoons. Furthermore, lead concentrations were 6 times the lowest observable adverse effects level for small mammals in the hair of one individual M. macropus. The present study demonstrates that coastal lagoons support a rich bat community, but ongoing development and pollution of these habitats is likely to negatively impact on insectivorous bat species, especially trawling species.
|Letnic et al.||2016||The crest-tailed mulgara (Dasycercus cristicauda) in the south-eastern Strzelecki Desert||
Our survey trips always uncover something surprising. Recently we observed a range extension of the crest-tailed mulgara or ampurta, (Dasycercus cristicauda), which was very exciting! We discuss our observations in an article published in Australian Mammalogy. The article can be accessed here: http://www.publish.csiro.au/paper/AM15027.htm
We report observations of the crest-tailed mulgara (Dasycercus cristicauda) in the south-eastern Strzelecki Desert. Our observations, made during spotlight surveys and using infrared cameras, extend the contemporary range of D. cristicauda to the east by 180 km but subfossil records show that these observations are within the pre-European-settlement range of the species. Whether our observations represent a range expansion or localised population irruption of a previously unknown refuge population is not known. Future studies are recommended to establish the distribution of D. cristicauda in the region and the factors determining its distribution and abundance
|Purwandana et al.||2016||Ecological allometries and niche use dynamics across Komodo dragon ontogeny||
Ontogenetic allometries in ecological habits and niche use are key responses by which individuals maximize lifetime fitness. Moreover, such allometries have significant implications for how individuals influence population and community dynamics. Here, we examined howbody size var- iation in Komodo dragons (Varanus komodoensis)influenced ecological allometries in their: (1) prey size preference, (2) daily movement rates, (3) home range area, and (4) subse- quent niche use across ontogeny. With increased body mass, Komodo dragons increased prey size with a dramatic switch from small (≤10 kg) to large prey (≥50 kg) in lizards heavier than 20 kg. Rates of foraging movement were described by a non-linear concave down response with lizard increasing hourly movement rates up until ∼20 kg body mass before decreasing daily movement suggesting reduced foraging ef- fort in larger lizards. In contrast, home range area exhibited a sigmoid response with increased body mass. Intrapopulation ecological niche use and overlap were also strongly structured by body size. Thus, ontogenetic allometries suggest Komodo dragon’s transition from a highly active foraging mode exploiting small prey through to a less active sit and wait feeding strategy focused on killing large ungulates. Further, our results suggest that as body size increases across ontogeny, the Komodo dragon exhibited marked ontogenetic niche shifts that enabled it to function as an entire vertebrate predator guild by by exploiting prey across multiple trophic levels.
Read full publication here
|Murray et al.||2015||Tidal flats of the Yellow Sea: A review of ecosystem status and anthropogenic threats|
|Skidmore et al.||2015||Environmental science: Agree on biodiversity metrics to track from space||
Conservation scientists should collaborate more with space agencies, such as NASA and the European Space Agency (ESA), on identifying measures to help track biodiversity declines around the world. For full publication click here.
|Kingsford||2015||From barriers to limits to climate change adaptation: path dependency and the speed of change||
This review examines the broad-ranging effects of climate change with respect to six case studies: the Australian Alps, the Coorong and Lower Lakes, the Great Barrier Reef, the Macquarie Marshes, small inland communities affected by drought and the Torres Strait Islands.
|Murray||2015||Tidal flats are disappearing|
|Hunter et al.||2015||Reintroduction of Tasmanian devils to mainland Australia can restore top-down control in ecosystems where dingoes have been extirpated|
|Catelotti et al.||2015||Inundation Requirements for Persistence and Recovery of River Red Gums (Eucalyptus camaldulensis) in Semi-arid Australia||
The building of dams and diversion from rivers has had a major impact on the wetlands of the Murray-Darling Basin. The Macquarie Marshes is one of the better studied of these wetlands. It is a wetland of international importance under the Ramsar Convention, one which the Australian Government has formally notified the Ramsar Bureau of likely ecological change in character, predominantly because of the impacts of water resource development. To read the publication click here
|Abrahms et al.||2015||The context of road-use by African wild dogs highlights the importance of considering animal behaviour in conservation planning||
Roads are among the most widespread forms of landscape alteration globally, so effective conservation planning requires an understanding of how they can affect animal movement. Using novel GPS collar technology we found that the response to roads by endangered African wild dogs, Lycaon pictus, varied with behaviour as well as with habitat. African wild dogs selected roads when travelling, ignored them when running (mostly hunting) and avoided roads when resting. Road-use increased in denser habitats, suggesting that roads may enhance wild dog movement through the landscape. Overall, this work highlights the importance of animal behaviour in conservation planning. Click here for full publication.
|Tulloch et al.||2015||Why do we map threats? Linking threat mapping with actions to make better conservation decisions|
|Leo et al||2015||Interference competition: odours of an apex predator and conspecifics influence resource acquisition by red foxes||
Apex predators can impact smaller predators via lethal effects that occur through direct killing, and non-lethal effects that arise when fear-induced behavioural and physiological changes reduce the fitness of smaller predators. To read full publication, click here
|Bino et al.||2015||Developing State and Transition Models of Floodplain Vegetation Dynamics as a Tool for Conservation Decision-making: a Case Study of the Macquarie Marshes Ramsar Wetland||
Freshwater ecosystems provide a range of critical services including clean water, food, power as well as recreational and tourism. Although covering only a fraction of the earth’s surface (0.8%), freshwater ecosystems harbour a considerable proportion of biodiversity worldwide. They are also among the more vulnerable, degrading in quality and extent at disturbing rates. Australia’s freshwater ecosystems are no exception. Degradation has predominately been driven by increasing freshwater demand and construction of dams, diminishing and altering the flow of water. To read the publication click here
|Kingsford et al.||2015||A commentary on ‘Long-term ecological trends of flow-dependent ecosystems in a major regulated river basin’, by Colloff et al.||
Colloff et al. in Marine and Freshwater Research (http:dx.doi.org/10.1071/MF14067) examined time-series data for flow-dependent vegetation, invertebrates, fish, frogs, reptiles and waterbirds in the Murray–Darling Basin, 1905–2013. They concluded that temporal patterns fluctuated, declining during droughts and recovering after floods. They suggested that major changes in land use in the late 19th century permanently modified these freshwater ecosystems, irretrievably degrading them before major water diversions. Restoring water to the environment might then be interpreted as not addressing biotic declines. We argue that their conclusions are inadequately supported, although data quality remains patchy and they neglected the influence of hydrology and the timing and extent of water resource development. We are critical of the lack of adequate model specification and the omission of statistical power analyses. We show that declines of native flow-dependent flora and fauna have continued through the 20th and early 21st centuries, in response to multiple factors, including long-term changes in flow regimes. We argue that flow-regime changes have been critical, but not in isolation. So, returning water to the environment is a prerequisite for sustained recovery but governments need to improve monitoring and analyses to adequately determine effectiveness of management of the rivers and wetlands of the Murray–Darling Basin.
Full text: http://www.publish.csiro.au/?paper=MF15185
|Pomilia et al||2015||African wild dog ranging patterns in northern Botswana|
|Rees et al.||2015||Ravens are a key threat to beach-nesting birds||
Fish waste left on beaches by recreational fishers could harm shore-nesting birds by attracting native crows that eat the birds’ eggs. To read full publication, click here
|Bino et al.||2015||Life history and dynamics of a platypus (Ornithorhynchus anatinus) population: four decades of mark-recapture surveys||
Knowledge of the life-history and population dynamics of Australia’s iconic and evolutionarily distinct platypus (Ornithorhynchus anatinus) remains poor. We marked-recaptured 812 unique platypuses (total 1,622 captures), over four decades (1973–2014) in the Shoalhaven River, Australia. Strong sex-age differences were observed in life-history, including morphology and longevity. Apparent survival of adult females (Φ = 0.76) were higher than adult males (Φ = 0.57), as in juveniles: females Φ = 0.27, males Φ = 0.13. Females were highly likely to remain in the same pool (adult: P = 0.85, juvenile: P = 0.88), while residency rates were lower for males (adult: P = 0.74, juvenile: P = 0.46). We combined survival, movement and life-histories to develop population viability models and test the impact of a range of life-history parameters. While using estimated apparent survival produced unviable populations (mean population growth rate r = −0.23, extinction within 20 years), considering residency rates to adjust survival estimates, indicated more stable populations (r = 0.004, p = 0.04 of 100-year extinction). Further sensitivity analyses highlighted adult female survival and overall success of dispersal as most affecting viability. Findings provide robust life-history and viability estimates for a difficult study species. These could support developing large-scale population dynamics models required to underpin a much needed national risk assessment for the platypus, already declining in parts of its current distribution.
|Morris et al.||2015||Divergent foraging behaviour of a desert rodent, Notomys fuscus, in covered and open microhabitats revealed using GUDs and video analysis|
|Kennish et al, 2015||2015||Saltmarshes||
For full publication click here
|Bino et al.||2015||Prioritizing Wetlands for Waterbirds in a Boom and Bust System: Waterbird Refugia and Breeding in the Murray-Darling Basin||
A systematic prioritisation of wetlands for waterbirds, across about 13.5% of the Murray-Darling Basin, using a 30-year record of systematic aerial surveys of waterbird populations.
|Feit et al.||2015||Invasive Cane Toads’ Predatory Impact on Dung Beetles is Mediated by Reservoir Type at Artificial Water Points|
|Rodríguez et al.||2015||A practical guide to the application of the IUCN Red List of Ecosystems criteria|
|Baker et al||2015||A composite annual-resolution stalagmite record of North Atlantic climate over the last three millennia||
Research on limestone formations in a remote Scottish cave has produced a unique 3000-year-long record of climatic variations that may have influenced historical events including the fall of the Roman Empire and the Viking Age of expansion. For full publication click here
|Keith et al.||2015||The IUCN red list of ecosystems: Motivations, challenges and applications|
|Ripple et al.||2014||Status and ecological effects of the world’s largest carnivores|
|Timms||2014||Aquatic invertebrates of pit gnammas in southwest Australia|
|Porter and Kingsford||2014||Aerial Survey of Wetland Birds in Eastern Australia - October 2014 Annual Summary Report||View PDF|
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