Suchergebnisse

Context Wild cats (Felis spp.) are difficult to monitor because of their cryptic lifestyle and usually low numbers. Hair-snaring is a promising non-invasive method being used increasingly to estimate mammal populations. Aims Our aim was to carry out pilot trials of a simple hair-snare designed to capture hair from wild cats in arid environments. Methods Roughened wooden stakes were set at multiple sites on the crests of sand dunes and in swales in western Queensland, Australia, and in mostly sandy habitats of the Namib and Kalahari Deserts, Namibia. In Australia, stakes were sprayed with cat urine, extracts of catnip or valerian herbs as lures, or left untreated; in Namibia, alternate stakes were sprayed with a food lure of tuna emulsion oil. The stakes were checked for hair, usually daily, for 2–14 days, and the surrounding ground was inspected for tracks. Remote cameras also were used at some sites to confirm the identity of visitors to stakes. Key results In Australia, feral cats (Felis catus) were attracted to, and left hairs on, stakes sprayed with cat urine six times more frequently than to unsprayed stakes irrespective of whether snares were on dune crests or in swales, and showed no response to catnip or valerian. Tracks and photos showed that cats, dingoes or wild dogs (Canis lupus ssp.) and foxes (Vulpes vulpes) also approached and sniffed the stakes. In Namibia, F. catus, F. lybica and F. nigripes left hair on stakes, with deposition rates two and a half-fold higher at stakes with the food lure than without it. At least five other species of predators visited the hair-snare sites. Conclusions Simple wooden stakes provide a cheap and simple method of snaring hairs from wild cats, especially if used in conjunction with appropriate lures. Our results broadly support previous work, and extend the utility of the method to different Felis spp. in arid habitats. Implications Further research is needed on snares to investigate the seasonal efficiency of different lures. If DNA also is to be extracted to identify individuals, more work is needed to confirm that snares yield hair of sufficient quality to allow this.

In New South Wales, at least 28 species of native rodents have been recorded
since European settlement. Four of these are extinct nationally, six are
extinct in the State, six are vulnerable and four are endangered; only eight
remain non-threatened. Declines and losses have been greatest in central and
western New South Wales and least in the State's north-east. Neither
body weight nor habit are associated with status, but taxa such as
Rattus species with broad diets and habitat preferences
remain generally less threatened than ecological specialists. Threatening
processes affect all vulnerable and endangered species, with predation from
introduced carnivores, grazing from livestock, clearance of vegetation and
changed fire regimes being among the most severe. No species occur entirely on
reserved land, while two endangered species have no secure land tenure. A
program of survey, research, management and education is proposed to help
achieve recovery.

Context
Feral cats (Felis catus) threaten biodiversity in many parts of the world, including Australia. Low-level culling is often used to reduce their impact, but in open cat populations the effectiveness of culling is uncertain. This is partly because options for assessing this management action have been restricted to estimating cat activity rather than abundance.

Aims
We measured the response, including relative abundance, of feral cats to a 13-month pulse of low-level culling in two open sites in southern Tasmania.

Methods
To do this we used remote cameras and our analysis included identification of individual feral cats. We compared estimates of relative abundance obtained via capture–mark–recapture and minimum numbers known to be alive, and estimates of activity obtained using probability of detection and general index methods, pre- and post-culling. We also compared trends in cat activity and abundance over the same time period at two further sites where culling was not conducted.

Key results
Contrary to expectation, the relative abundance and activity of feral cats increased in the cull-sites, even though the numbers of cats captured per unit effort during the culling period declined. Increases in minimum numbers of cats known to be alive ranged from 75% to 211% during the culling period, compared with pre- and post-cull estimates, and probably occurred due to influxes of new individuals after dominant resident cats were removed.

Conclusions
Our results showed that low-level ad hoc culling of feral cats can have unwanted and unexpected outcomes, and confirmed the importance of monitoring if such management actions are implemented.

Implications
If culling is used to reduce cat impacts in open populations, it should be as part of a multi-faceted approach and may need to be strategic, systematic and ongoing if it is to be effective.

SIMPLE SUMMARY: The domestic cat, Felis catus, is often cross-bred with other species in the cat family to produce hybrid or 'designer' cats that are sought by people as pets. However, hybrid cats are often surrendered to wildlife shelters, or released, which leads to concern that they may establish free-roaming populations and damage native wildlife. In 2008, the Australian government rejected an application, on precautionary grounds, to import savannah cats (hybrids of the domestic cat and serval Leptailurus serval) into the country. We review the limited information informing this decision and then present a framework that identifies the native mammal species likely to have been most at risk of predation from savannah cats if importation and establishment had occurred. Assuming that savannah cats hunt similar prey to those that are hunted by both parent species, we estimate that 91% of Australia's extant terrestrial mammal fauna would likely face some risk of predation from savannah cats, including 93% of non-volant mammal species that have threatened conservation status. The framework results strongly validate the decision to ban savannah cats from Australia. We suggest that our framework approach could be adapted to assess the likely risks that are posed by the arrival of other hybrid cats or hybrids of other animals. ABSTRACT: Hybrid cats—created by crossing different species within the family Felidae—are popular pets, but they could potentially threaten native species if they escape and establish free-roaming populations. To forestall this possibility, the Australian government imposed a specific ban on importation of the savannah cat, a hybrid created by crossing the domestic cat Felis catus and serval Leptailurus serval, in 2008. We develop a decision–framework that identifies those species of non-volant native mammals in Australia that would likely have been susceptible to predation by savannah cats if importation and establishment had occurred. We assumed that savannah cats would hunt ecologically ...

Abstract
Pet cats (Felis catus) often have negative effects on wildlife. This is of growing concern in urban areas as these are increasingly becoming hotspots of native wildlife activity, and as the human population increases, so too does the pet cat population. To maintain biodiversity in urban areas, further knowledge on pet cat behaviour and impacts is required so that management strategies for pet cats are well informed and have public and government support. Here, we offer insights into the wandering activity of pet cats in a patchy urban—heavily vegetated landscape on the east coast of Australia. Our estimated pet cat movement ranges were generally larger than those previously observed in similar landscapes, as well as in more urbanized and rural habitats. Using GPS data loggers, we found that pet cats did not utilize vegetated spaces more than urban areas, nor did they prefer them relative to their availability. Half of our study cats selected urban habitats, whilst the other half displayed no selection or a slight preference for vegetated spaces; these cats had fewer barriers to overcome to reach them. We did not observe any large differences in movements or habitat use between day and night, but displacement distances and preference for vegetated space habitat were marginally lower at night. All pet cats monitored spent most of their time outside their houses. As both urban and vegetated spaces in patchy urban landscapes provide habitat for native wildlife, pet cat activity across both habitat types requires management action.

Context The Eurasian red fox (Vulpes vulpes) is a widespread pest in mixed agricultural and remnant forest habitats in southern Australia, and is controlled most commonly with baits containing poison (1080) to protect both agricultural and ecological assets. An understanding of fox movements in such habitats should assist in the strategic placement of baits and increase bait encounters by foxes across the landscape, thus improving the success of control efforts. Aims We seek to understand the ranges, movements and habitat use of foxes to aid the development of effective management plans. The fate of tracked animals was examined during a control program. Methods We radio-tracked 10 foxes using VHF transmitters and three foxes using GPS receivers during control operations in a remnant forest area near Dubbo, New South Wales. We used VHF location fixes to estimate fox range areas and GPS fixes to describe temporal and spatial aspects of fox movements and range use, focal points of activity and potential bait encounters. Selection of forest versus cleared areas was assessed, as was the impact of control operations on collared foxes. Key results Range areas (mean ± s.e.; 95% minimum convex polygon) for VHF- and GPS-tracked foxes were 420 ha ± 74 and 4462 ha ± 1799 respectively. Only small parts of range areas were visited on a daily basis, with little overlap. Animals were often within 200 m of roads and crossed or travelled on roads more than expected. At least 75% of collared foxes were probably poisoned in the control program. Conclusions Foxes occupy large ranges and move long distances in the study region, with little daily overlap, so successful defence of range areas is unlikely. Control efforts successfully poisoned foxes but also limited data collection because of reduced tracking periods. Implications The large and variable areas occupied by foxes suggested that control efforts need to be on-going, coordinated across the landscape, and use a minimum bait density of 0.5 baits per 100 ha in remnant forest habitat to ensure that gaps are minimised. Control operations should target roads and forest edges for bait placement, and increase the time that baits are available, to increase fox encounters and maximise the success of control efforts.

Context
The European red fox (Vulpes vulpes) is subject to control by poison baiting in many parts of its range in Australia to protect both native and domestic species. Assessments of baiting programs can improve their effectiveness and help ensure that long-term control outcomes are achieved.

Aims
We describe spatial and temporal patterns of bait uptake by the red fox in remnant forest within an agricultural matrix, including multiple bait-takes and hotspots of activity over time, and examine the response of foxes to baiting operations.

Methods
We analysed bait uptake (Foxoff®) from 12 baiting operations over 5 years in the Goonoo forest, a 62 500 ha remnant surrounded by cleared land in central New South Wales, Australia. More than 8000 checks of bait-stations were analysed to provide indices of fox activity per bait-check, patterns of bait removal during bait-checks, and bait uptake at stations within and across operations. Fox activity was also assessed before and after four operations using sand plots.

Key results
There was no consistent decline in relative fox activity in relation to changes in bait-take; increases in the activity index occurred in successive checks within most operations. Spatial analyses of checks within control operations showed that consecutive baits were removed at more than 70% of bait stations that were visited by foxes. Temporal analyses showed further that within an operation, multiple bait-takes occurred at ~20% of stations and, across all operations, hot spots of activity could be identified.

Conclusions
A short (2-week) baiting window in standard baiting operations may not be effective in reducing the activity of foxes across the landscape. It is likely that many baits are being cached during each operation, and that foxes move into the baited area from unbaited surrounding areas.

Implications
More frequent and timely baiting operations are needed to achieve maximum disruption to the fox population in the remnant forest environment, at least as indicated by patterns of bait-take. Increasing the distance between baits, to ~1.5 km, while reducing baiting-gaps at the landscape scale, will also be important to reduce caching and still ensure that baits are encountered.

Context The red fox (Vulpes vulpes) is a widespread pest in southern Australia and is subject to control over large areas using poison baits to protect both agricultural and ecological assets. Foxes and their prey are often cryptic or in low densities, making it difficult to quantify the efficacy of control programs. Aims We explore the use of remote cameras to estimate the activity and spatial occupancy of foxes and potential mammalian and avian prey species before and after poison baiting in the Goonoo region, central New South Wales. Methods In the first of two studies, we set camera traps at 48 sites in forest and cleared areas, on and off tracks, during autumn 2009. In the second study, we placed camera traps in forest and cleared areas, on tracks only, at 100 sites covering an area of ~441 500 ha during winter 2009. We examined camera-trap rates of all species detected and the activity and site occupancy of a selected subset of species before and after poison baiting. Key results Camera traps indicated greater levels of fox activity on vehicular tracks than off them, with this difference being more marked in forest than in cleared agricultural land. Fox activity and occupancy were greater in agricultural land than in forest, with no effect of baiting detected at the landscape scale. Thirty-five other mammal and bird species were identified from photos, with activity for most being greater on than off tracks. Conclusions No clear effects of fox-baiting were detected on foxes or potential prey species in either study by either activity or occupancy. The lack of a baiting effect may reflect rapid recolonisation by foxes from unbaited areas, as bait placement is generally clustered in agricultural land, or the ready availability of alternative food (lambs or lamb carcasses) in some cleared areas. Implications Our results demonstrate that remote cameras provide a simple means of monitoring changes in fox activity and occupancy at the landscape level, and that these measures have great potential to quantify the success or otherwise of fox-control campaigns on both pest and prey species.

Context Many rare and endangered species are threatened by the effects of hybridisation with their domesticated and often numerically dominant relatives. However, factors that influence interactions between hybridising species are poorly understood, thus limiting our ability to develop ameliorative strategies. Aims Here, we identify family groups and investigate patterns of gene flow between dingoes (Canis lupus dingo) and domestic dogs (C. l. familiaris) in the Tanami Desert of central Australia. We aimed to determine whether human-provided resources facilitate hybridisation or alter typical patterns of dingo breeding and social behaviour. We also ask whether remote townships are arenas for dingo–dog hybridisation. Methods Tissue samples and morphological details were collected from dingo-like animals around two mine sites where humans provide abundant supplementary food and water. Using molecular DNA analyses, we assigned animals to population clusters, determined kinship and the numbers of family groups. Rates of hybridisation were assessed around the mines and in two nearby townships. Key results Of 142 samples from mine sites, 'pure' dingoes were identified genetically in 89% of cases. This predominance of dingoes was supported by our observations on coat colour and body morphology. Only 2 of 86 domestic dogs sampled at the two townships showed evidence of dingo ancestry. Around the mine sites, there were two distinct population clusters, including a large family group of 55 individuals around a refuse facility. Conclusions Where superabundant and consistent food, and reliable water, was available, dingo packs were much larger and co-existed with others, contrary to expectations derived from previous research. Dingo sociality and pack structures can therefore be altered where human-provided food and water are constantly available, and this could facilitate accelerated rates of hybridisation. Implications The development of appropriate domestic-waste management strategies should be a high priority in remote areas to ensure only normal rates of population increase by dingoes, and other canids more broadly. It will also potentially impede hybridisation rates if typical canid social and behavioural traits remain intact. Additionally, areas surrounding remote human settlements are likely arenas for accentuated dingo–domestic dog interactions and should be a target for future studies.

This study investigated the population dynamics of three species of dasyurid
marsupials in sand ridge habitat of the Simpson Desert, western Queensland,
over a 10-year period between March 1990 and December 1999. The lesser
hairy-footed dunnart (Sminthopsis youngsoni), was
captured most consistently over the period of study, followed by the wongai
ningaui (Ningaui ridei), and the mulgara
(Dasycercus cristicauda). Rates of recapture were low
(4.5–22.2%), probably because individuals of each species are
very mobile. All species bred in late winter or early spring when animals were
aged at least 8–10 months, and independent juveniles first appeared
usually in summer. S. youngsoni reared a second litter
in late spring or early summer in 3 of the 10 years studied, when the
availability of food was likely to have been high; neither
N. ridei nor D. cristicauda were
known to attempt a second litter within a season.
To explore factors that might influence population dynamics, we compared
capture rates of each species with measures of rainfall, temperature,
vegetation cover, abundance of predators [feral cats
(Felis catus), red foxes
(Vulpes vulpes), and goannas
(Varanus spp.)], dragons, other dasyurids and
indices of food abundance. The abundance of S. youngsoni appeared to depend
primarily on the cover of spinifex 7–9 months earlier, that of
D. cristicauda was related most strongly to rainfall
7–9 months earlier, while that of N. ridei was
related to minimum temperature lagged by 1–3 months.
While the dynamics of other arid-zone mammals are driven demonstrably by
interactions between rainfall, resource availability and predation, our
findings suggest that dasyurids have limited flexibility in their life
histories and are influenced more subtly and by factors such as facilitation
that are just beginning to become apparent.

International differences in practices and attitudes regarding pet cats' interactions with wildlife were assessed by surveying citizens from at least two cities in Australia, New Zealand, the UK, the USA, China and Japan. Predictions tested were: (i) cat owners would agree less than non-cat owners that cats might threaten wildlife, (ii) cat owners value wildlife less than non-cat owners, (iii) cat owners are less accepting of cat legislation/restrictions than non-owners, and (iv) respondents from regions with high endemic biodiversity (Australia, New Zealand, China and the USA state of Hawaii) would be most concerned about pet cats threatening wildlife. Everywhere non-owners were more likely than owners to agree that pet cats killing wildlife were a problem in cities, towns and rural areas. Agreement amongst nonowners was highest in Australia (95%) and New Zealand (78%) and lowest in the UK (38%). Irrespective of ownership, over 85% of respondents from all countries except China (65%) valued wildlife in cities, towns and rural areas. Non-owners advocated cat legislation more strongly than owners except in Japan. Australian non-owners were the most supportive (88%), followed by Chinese non-owners (80%) and Japanese owners (79.5%). The UK was least supportive (non-owners 43%, owners 25%). Many Australian (62%), New Zealand (51%) and Chinese owners (42%) agreed that pet cats killing wildlife in cities, towns and rural areas was a problem, while Hawaiian owners were similar to the mainland USA (20%). Thus high endemic biodiversity might contribute to attitudes in some, but not all, countries. Husbandry practices varied internationally, with predation highest where fewer cats were confined. Although the risk of wildlife population declines caused by pet cats justifies precautionary action, campaigns based on wildlife protection are unlikely to succeed outside Australia or New Zealand. Restrictions on roaming protect wildlife and benefit cat welfare, so welfare is a better rationale.

Aim: After environmental disasters, species with large population losses may need urgent protection to prevent extinction and support recovery. Following the 2019-2020 Australian megafires, we estimated population losses and recovery in fire-affected fauna, to inform conservation status assessments and management. Location: Temperate and subtropical Australia. Time period 2019-2030 and beyond. Major taxa: Australian terrestrial and freshwater vertebrates; one invertebrate group. Methods: From > 1,050 fire-affected taxa, we selected 173 whose distributions substantially overlapped the fire extent. We estimated the proportion of each taxon's distribution affected by fires, using fire severity and aquatic impact mapping, and new distribution mapping. Using expert elicitation informed by evidence of responses to previous wildfires, we estimated local population responses to fires of varying severity. We combined the spatial and elicitation data to estimate overall population loss and recovery trajectories, and thus indicate potential eligibility for listing as threatened, or uplisting, under Australian legislation. Results: We estimate that the 2019-2020 Australian megafires caused, or contributed to, population declines that make 70-82 taxa eligible for listing as threatened; and another 21-27 taxa eligible for uplisting. If so-listed, this represents a 22-26% increase in Australian statutory lists of threatened terrestrial and freshwater vertebrates and spiny crayfish, and uplisting for 8-10% of threatened taxa. Such changes would cause an abrupt worsening of underlying trajectories in vertebrates, as measured by Red List Indices. We predict that 54-88% of 173 assessed taxa will not recover to pre-fire population size within 10 years/three generations. Main conclusions We suggest the 2019-2020 Australian megafires have worsened the conservation prospects for many species. Of the 91 taxa recommended for listing/uplisting consideration, 84 are now under formal review through national processes. Improving ...