Hughes N.K.,Australian Wildlife Conservancy |
Korpimaki E.,University of New South Wales |
Banks P.B.,University of Turku
Oikos | Year: 2010
Competing species benefit from eavesdropping on each other's signals by learning about shared resources or predators. But conspicuous signals are also open to exploitation by eavesdropping predators and should also pose a threat to other sympatric prey species. In western Finland, sibling voles Microtus rossiameridionalis and field voles M. agrestis compete for food and space, and both species rely upon scent marks for intraspecific communication. Both vole species are prey to a range of terrestrial scent hunting predators such as least weasels, however, the competitively superior sibling voles are taken preferentially. We tested in large out-door enclosures whether field voles eavesdrop on the signals of its competitor, and whether they behave as though this eavesdropping carries a risk of predation. We presented field voles with scent marks from unknown conspecifics and sibling voles and measured their visitation, activity and scent marking behaviours at these scents under high (weasel present) and low (weasel absent) predation risk. Field voles readily visited both field and sibling vole scents under both high and low predation risk; however their activity at sibling vole scent marks declined significantly under increased predation risk. In contrast, predation risk did not affect field voles' activity at conspecific scents. Thus, field voles were compelled to maintain eavesdropping on heterospecific scents under an increased risk of predation, however they compensated for this additional risk by reducing their activity at these risky scents. Scent marking rates declined significantly under high predation risk. Our results therefore reveal a hidden complexity in the use of social signals within multi-species assemblages that is clearly sensitive to the potential for increased predation risk. The predation risks of interspecific eavesdropping demonstrated here represents a significant generalisation of the concept of associational susceptibility. © 2010 The Authors.
Hayward M.W.,Australian Wildlife Conservancy |
Hayward M.W.,University of New South Wales |
Hayward M.W.,University of Pretoria |
Hayward M.W.,Nelson Mandela Metropolitan University
Biodiversity and Conservation | Year: 2011
Threatened species lists continue to grow while the world's governments fail to meet biodiversity conservation goals. Clearly, we are failing in our attempts to conserve biodiversity. Yet 37 mammal species genuinely improved in status in the 2009 IUCN Red List, suggesting there are ways to successfully conserve biodiversity. Here, I compare the threats and conservation actions (proposed and implemented) by the expert assessors of the Red List of improving species to a further 144 declining mammal species to determine whether specific threats were more easily remedied, and whether certain conservation actions were more successful than others. Declining species were faced with different threatening processes to mammals improving in status suggesting some threats were easier to treat (e. g. hunting) than others (climate change, invasive species). Declining species had different proposed and implemented conservation actions than improving species suggesting some actions are more successful than others. Threatened species were invariably found in conservation areas, suggesting protected area creation alone is not an overly successful strategy for species at risk of extinction. Conservation actions were more frequently implemented for improving than declining species suggesting active conservation is effective in improving the status of biodiversity. There were significant differences between proposed and implemented conservation actions suggesting some actions are easier to implement than others. Reintroduction, captive breeding and hunting restriction were more effective in conserving mammals than site creation and invasive species control. These findings highlight effective conservation actions for mammals worldwide and allow the rationalisation of threat mitigation measures to ensure economically justifiable biodiversity conservation strategies. © 2011 The Author(s).
Skroblin A.,Australian National University |
Legge S.,Australian Wildlife Conservancy |
Legge S.,Charles Darwin University
PLoS ONE | Year: 2013
Conservation of species that are patchily distributed must consider processes that influence both the occurrence of individuals within patches, and the persistence of populations across multiple habitat patches within the landscape. Here we present a rare regional assessment of the population size and distribution of a patchily distributed, threatened species, the purple-crowned fairy-wren (Malurus coronatus coronatus), across a vast landscape. We used data from aerial vegetation mapping of waterways, with on-ground bird surveys to predict the occurrence of suitable habitat for M. c. coronatus across 14 catchments in the Kimberley region of Western Australia. Suitable habitat was extremely limited (305 km of riparian vegetation) and fragmented (342 patches) along the 2700 km of waterway surveyed within catchments where the species occurs. Populations were predicted to be large on the Fitzroy, Durack and Drysdale catchments, and small on the Isdell and northern Pentecost catchments, and a total population of 2834 to 4878 individuals could be supported. The sub-populations spanned numerous patches of habitat across multiple properties of varying tenure. Therefore, a landscape-scale approach to conservation management, across multiple tenures, is critical to safe-guard connectivity within populations. The greatest benefit may be achieved by a combination of broad-scale actions to reduce the impact of ubiquitous threatening processes, and fine-scale targeted effort in areas where populations are most vulnerable. Controlling access of stock to waterways and management of fire are most important to conserve suitable habitat. Such a landscape-scale approach to conservation may be of benefit to other patchily distributed species. © 2013 Skroblin and Legge.
Winterbach H.E.K.,University of Pretoria |
Winterbach C.W.,University of Pretoria |
Somers M.J.,University of Pretoria |
Hayward M.W.,Australian Wildlife Conservancy
Mammal Review | Year: 2013
Large carnivores are a critical component of Africa's biodiversity, and their conservation requires a clear understanding of interactions between large carnivores and people. By reviewing existing literature, we identify 14 key factors that influence large African carnivore conservation, including ecological (biodiversity conservation, interspecific competition, ranging behaviour, ecological resilience, prey availability, livestock predation, disease and population viability), socio-economic (people's attitudes and behaviours and human costs and benefits of coexistence with large carnivores) and political (conservation policy development and implementation, conservation strategies and land use zoning) factors. We present these key factors in a model illustrating the levels of impact on large African carnivore conservation. We identify the key principle that underpins each factor and its implications for both large carnivore conservation and human-carnivore conflict. We provide a synthesis of the key factors and related principles in large African carnivore conservation and highlight the importance of the site-specific and species-specific context in conservation policy and implementation, formulated through an interdisciplinary and adaptive approach. © 2013 Mammal Society/Blackwell Publishing.
News Article | February 21, 2017
Murdoch University PhD student Diana Prada has begun a three-year investigation into the region's microbats, to better understand these creatures and the diseases they host. "We currently know very little about these animals in the region despite bats making up almost one-quarter of all known mammal species," Ms Prada said. "These insectivorous microbats play a major role in controlling pests for the agricultural industry as well as contributing to biodiversity, so their survival and their health are important." Diana and her PhD supervisors Dr Bethany Jackson, Dr Mark O'Dea and A/Prof Peter Spencer have embarked on an ambitious project to learn more about this largely unknown group of mammals. They aim to learn more about the genetic diversity of the microbat populations, and their genetic connectivity while examining potential disease threats to the bats as well as humans. On the first field trip of the season the team captured, sampled and released more than 250 bats from the Australian Wildlife Conservancy's Mt Gibson Wildlife Sanctuary and nearby Bush Heritage Australia's Charles Darwin Reserve. "We trapped seven different species of microbats and later in the year we will be in the lab generating all the data. We want to work out the genetic diversity of the populations and how viruses are distributed amongst the bat populations," Diana said. "These results will give us insights into any potential health risks for the bats, as well as people coming into contact with them, and also give us important baseline information to conserve these cryptic animals." The research team has now moved into new areas, capturing animals at other locations around the Perth hills and further south. The project is conducted in reserves managed by the Australian Wildlife Conservancy and Bush Heritage Australia and it is partially funded by the Holsworth Wildlife Research Endowment.
McGregor H.W.,University of Tasmania |
Legge S.,Australian Wildlife Conservancy |
Jones M.E.,University of Tasmania |
Johnson C.N.,University of Tasmania
PLoS ONE | Year: 2014
Intensification of fires and grazing by large herbivores has caused population declines in small vertebrates in many ecosystems worldwide. Impacts are rarely direct, and usually appear driven via indirect pathways, such as changes to predator-prey dynamics. Fire events and grazing may improve habitat and/or hunting success for the predators of small mammals, however, such impacts have not been documented. To test for such an interaction, we investigated fine-scale habitat selection by feral cats in relation to fire, grazing and small-mammal abundance. Our study was conducted in northwestern Australia, where small mammal populations are sensitive to changes in fire and grazing management. We deployed GPS collars on 32 cats in landscapes with contrasting fire and grazing treatments. Fine-scale habitat selection was determined using discrete choice modelling of cat movements. We found that cats selected areas with open grass cover, including heavily-grazed areas. They strongly selected for areas recently burnt by intense fires, but only in habitats that typically support high abundance of small mammals. Intense fires and grazing by introduced herbivores created conditions that are favoured by cats, probably because their hunting success is improved. This mechanism could explain why, in northern Australia, impacts of feral cats on small mammals might have increased. Our results suggest the impact of feral cats could be reduced in most ecosystems by maximising grass cover, minimising the incidence of intense fires, and reducing grazing by large herbivores. 2014 McGregor et al.
News Article | August 31, 2016
But this age-old animal kingdom certainty has now been put to use as part of the biggest cat research project in the country. Australian Wildlife Conservancy (AWC) scientists are using specially trained dogs to help capture cats, so the researchers can fit the felines with GPS systems and video cameras and then release them. Information gleaned from such monitoring has shown cats frequent heavily grazed or recently burnt areas, thus informing conservation work to ease the massive threat that feral cats pose to rare and endangered native animals. Previously AWC scientists relied on soft-hold jaw traps to catch the cats. But cats are wily creatures and tricky to catch. There had to be another way. Lightbulb moment: use an animal already very keen on chasing them. Dogs. The first such dog was an enthusiastic springer spaniel named Sally. Sally underwent a training process that taught her how to chase cats, while ignoring all other animal scents. University of Tasmania PhD student Hugh McGregor says Sally's only downfall was the cats' crafty nature. "Sally was full of beans and enthusiasm but she wasn't the smartest in terms of cat hunting and there were many instances where the cats outwitted her," Dr McGregor says. "It was that classic cartoon image of the dog chasing the cat, the cat stopping still and the dog jumping right over the cat and continuing to run." Enter a new dog—a Catahoula named Brangul. While Brangul wasn't as enthusiastic about cat hunting she had the wits to counter the cats' evasion tactics. Sally's enthusiasm for the hunt combined with Brangul's guile made for a great team and together the duo caught 114 of an attempted 160 cat captures over four years at Mornington Marion Downs Wildlife Sanctuary in the Kimberley. AWC staff would spotlight for cats at night and release the dogs upon sighting the cats' glowing eyes. The muzzled dogs would set off in pursuit and either chase the cats up trees, into caves or hold them to the ground until the scientists caught up. Cats in trees or caves were darted with an anaesthetic to enable scientists to fit them with GPS collars or tiny video cameras before release. Dr McGregor says dogs had a much higher success rate than live-trapping with leg-hold traps, took less effort in terms of person-hours and caused less physical injuries than leg-hold traps. Explore further: Cats versus dogs in the 'drinking' category (w/ video)
News Article | October 25, 2016
The elusive night parrot has been recorded in Diamantina national park in central-west Queensland, expanding its known range and leading scientists to believe it may not be as rare as previously thought. The bird, described by Bush Heritage Australia’s Jim Radford as a “dumpy budgerigar” or a “podgy, sort of smallish, green and yellow parrot”, was thought to be extinct for more than 100 years before ornithologist John Young managed to photograph it in 2013. That discovery was made on an area of reclaimed pastoral lease now known as Pullen Pullen nature reserve. This month, another team of researchers from the Australian Wildlife Conservancy (AWC) and the Queensland Parks and Wildlife Service, led by Young, announced they had found what they believe to be a larger population of night parrots in the nearby national park. The birds were discovered as part of a broader survey of threatened species in the park. Researchers made seven records of the bird this year: four sightings, three of which included nests with eggs, and three recorded calls. “My immediate reaction was excitement – this is great, there are more birds out there than we thought,” Atticus Fleming, chief executive of AWC told Guardian Australia. “But when you start to analyse it, the really significant thing about this is that these birds may be more common than we thought. That is something that we will be developing in the next few years as the study extends into other areas.” The parrots were discovered in an area of the park bordered by the Diamantina and Mayne rivers. The Queensland government has declared that area a restricted access zone with hefty fines for unauthorised access to deter poachers or enthusiastic twitchers from seeking out the rare parrots. The same penalties apply for entering Pullen Pullen, which is owned and managed by Bush Heritage Australia. Radford, BHA’s head of science and research, listed poachers as one of the significant threats faced by the parrot, particularly now researches have reported spotting eggs in both Pullen Pullen and Diamantina. Other threats include cattle, feral cats and potential habitat destruction from bushfires, which destroy the tall spinifex clumps where night parrots make their nests. There are other dangers that go along with being a largely ground-dwelling parrot. In April researchers from BHA discovered eggs in a night parrot nest after heavy rain, only to return later and find shell fragments containing traces of what proved to be the DNA of a brown snake. “Which is an interesting discovery in and of itself because we didn’t realise that brown snakes would predate on eggs,” Radford said. It was an unfortunate loss but not a significant one. Unprecedented rainfall has pompted a breeding frenzy in the arid plains of central-west Queensland, and Radford said he expected that pair would breed again. “All indications are that it will be a very good year, not just for night parrots but for other birds,” he said. The night parrot is one of just two fully nocturnal bird species in the world. The other is New Zealand’s kakapo, famous for being the world’s heaviest parrot and for being particularly enamoured with zoologist Mark Carwardine. Scientists are now making a concerted effort to study the bird, a process made difficult by its nocturnal habits and the sparseness with which it is spread across a remote landscape. Like Fleming, Radford said the discovery of more birds at Diamantina was “not unexpected” but was significant for the hope it gave researchers that small populations of the birds may be tucked away in other areas of the remote desert. “I fully expect that they will be discovered in other places in Australia in time as well, because I don’t think that this can be the only population,” he said.
News Article | January 19, 2017
While Australia bakes through another hot, angry summer, its precious wildlife is increasingly under threat, not just from the extreme weather of fires and floods but by the growing reality of a changing climate. It is getting hotter. Day by day, month by month, year by year – 2016 is confirmed as the hottest year on record globally, closely following the leads of 2015 and 2014 – and with summer in full swing in Australia we turn our minds and our national concerns to bushfires, ever more intense, and to extreme weather events, flash flooding, cyclonic winds, unexpected parching and flooding of our wide brown land. And it is not just the Australian people who are feeling these stresses first hand, but some of the most unique wildlife to be found anywhere in the world. For those who have had the privilege of watching a platypus swim, of holding a koala, of watching kangaroos bound across seemingly endless plateaus – you should be well aware that these special creatures face a very uncertain future. Climate change from unprecedented carbon emissions not only threaten the habitats of our unique animals and birds, but also challenges the very ability of them to survive. This should be of concern to each and every one of us. Species lost, iconic animals threatened, wiped out, perhaps in a generation. This should provoke nothing short of shame in the hearts of people the world over. So what we can be sure about? Climate change is making Australia hotter. Hot days are happening more often while heatwaves are becoming hotter, longer and more frequent. While it has been clear for many years that climate change is a major factor in intensifying heat, recent scientific advances now allow us to understand the extent of the impact on individual extreme events. Climate change has significantly worsened recent extreme heat events in Australia. And the outlook just looks bleaker. The work of some great scientists from this side of the planet emphasises the very real threat to our unique wildlife. In addition, the most recent report by the Intergovernmental Panel on Climate Change (IPCC) stated that native species are set to “suffer from range contractions, and some may face local or even global extinction … Koalas, gliders, quokkas, platypus and several species of birds and fish will all suffer from shrinking habitats as temperatures increase, even under the most optimistic scenarios.” And it is not just our well known natural icons, it is the lesser known also. The golden-shouldered parrot, currently listed as endangered in Queensland, is only found in the southern and central Cape York Peninsula, and is now restricted to just two populations there – covering an area less than 2,000 sq km. This rare and beautiful bird will be one of many species that will likely be affected by increased temperatures, fires and droughts across Northern Australia. Then there is the little known Lumholtz’s tree kangaroo, a remarkable animal. According to the Australian Wildlife Conservancy, global warming poses a very real threat to this species. They thrive in a high-altitude, cool rainforest as these areas provide the kangaroo with a cool environment, keeping their body temperatures down with access to moisture from dew and mist formed under the rainforest canopy. There can be little doubt that increased atmospheric temperatures will significantly impact these habitats. Everywhere we turn we can see that our changing climate, and the extreme weather it delivers with a vengeance, is already having a profound and deeply disturbing impact on the flora and fauna that have made the Great Southern Land such a remarkable place - for travellers, for explorers, for discovery. It is a sad fact that the very country that risks losing these special places, these special and unique forms of life, is also playing such a key role in warming the planet. Our export coal industry is being pushed to expand and expand, despite all the economics and science one can throw at our leaders. So while other countries are winding down their coal use, Australia is attempting to ramp up our production and export of the product, all the while as we watch first-hand the immediate and long term damage coal and fossil fuels are wreaking on our planet, on people and on nature.
News Article | November 17, 2015
An eight-year study into fire regimes and its impact on finches in the Kimberley led by Australian Wildlife Conservancy ecologist Sarah Legge has filled part of the knowledge gap about fire regime's effects on endangered wildlife in one of the world's most pristine environments. "Grass seed eating birds have declined quite markedly across the savannahs of Australia and one of the hypotheses for this has been the change in fire regimes," Dr Legge says. The study determined Gouldian finches, double-barred finches (Taeniopygia bichenovii) and long-tailed finches (Poephila acuticauda), show anaemia and poor body condition when they repopulate scrub that is recovering from large hot fires with Gouldian finches the worst affected by hot fires. They came to this conclusion after capturing and studying finches in savannah that had been subjected to mosaic burns and hot burns. They tested the birds' blood for haematocrits (the proportion of a blood sample made up of cells) and concentrations of stress hormones, as well as muscle and fat volume. "All three finch species were showing the same sorts of changes in condition measures in different fire patterns," she says. "Once we confirmed that link we worked to see whether changing the fire regimes would cause the condition of individuals also to change with that management." The birds that repopulated mosaic-burned habitats flourished according to each of the study metrics. "What we showed is that the frequency of fire and the extent of long-unburned vegetation are the key things in relation to improved condition in these finches," De Legge says. "So you need to manage fire in these tropical savannah landscapes to reduce the fire frequency and increase the average age of the vegetation. Older vegetation results in higher feed-abundance across the landscape which in turn results in the persistence of finch populations. The study was carried out on Mornington Station, a very remote pastoral lease which Dr Legge says provided an unusual opportunity to integrate ecological research with landscape management. This remoteness made it possible to establish control areas for a key variable, fire. Therefore the researchers could establish continuously mosaic-burned patches throughout the study's life and compare their ecology of these with hot-burned areas, and hot-burned patches that are later mosaic burned.