Context . Hunting has demographic effects on large and medium carnivores, causing population reductions and even extinctions worldwide. Yet, there is little information on carnivore demographic parameters and spatial and temporal land-use patterns in areas experiencing sport hunting, thus hindering effective conservation plans for such areas.

Aims . We estimated densities and determined activity patterns of pumas (Puma concolor) from camera-trapping surveys in a protected area and in a game reserve with sport hunting, in the Caldén forest of central Argentina.

Methods . We used both non-spatial and spatial mark–resight techniques to estimate and compare puma densities and we used kernel-density estimation (KDE) techniques to analyse and compare puma activity patterns between study sites.

Key results . Puma densities estimated from spatial models were lower than densities estimated from non-spatial mark–resight techniques. However, estimated density of pumas in the protected area was always higher (range = 4.89–9.32 per 100 km²) than in the game reserve (range = 0.52–1.98 per 100 km²), regardless of the estimation technique used. Trapping rates for large mammal prey were similar across sites. Pumas exhibited more nocturnal behaviour and high activity peaks at 0600 hours and 1100 hours in the hunted game reserve, whereas puma activity was spread more evenly around the clock in the protected area.

Conclusions . The higher puma densities in the protected area reflect the potential for such areas to function as refugia in a human-dominated landscape. However, the game reserve had a lower puma density than the protected area despite high trap rates of large prey, indicating that these areas may function as attractive sinks.

Implications . Our results could indicate that puma sport hunting in the Caldén forest should be managed at a metapopulation, regional level, and include both no-hunting areas (protected area, as potential sources) and hunting areas (game reserves, as potential sinks). Considering that our study areas were small and that this was an unreplicated study, we urge more research to be conducted, so as to determine whether sport hunting is compatible with puma conservation in the region.

Context . Following centuries of intense human exploitation, the global stocks of hawksbill turtle have decreased precipitously and the species is currently considered Critically Endangered by the IUCN. Australia supports the largest breeding aggregations worldwide; however, there are no accurate estimates of population abundance and seasonality for hawksbill turtles at important nesting grounds in eastern Arnhem Land.

Aims . This study was designed to fill in this lack of ecological information and assist with the conservation and management of hawksbill turtles. More specifically, our overarching goals were to assess nesting seasonality, habitat preferences and provide the first estimate of annual nesting population size at a Northern Territory rookery.

Methods . In 2009 and 2010 we collected beach monitoring, satellite telemetry and sand temperature data over two nesting seasons at a group of three islands located 30 km off Groote Eylandt in the Gulf of Carpentaria, northern Australia. We subsequently analysed these data to unravel hawksbill nesting behaviour and reproductive outputs, and examined the vulnerability of this rookery to climate change.

Key results . Hawksbill turtle nesting seasonality consistently started in mid-May, peaked in mid-August and ended in late November. Annual nesting abundance showed a near 3-fold increase between 2009 and 2010, with an average of 220 and 580 hawksbill females nesting on this island group respectively. Sand temperature at 50 cm reached more than 30°C at all monitored sites during most of the peak of the incubation period.

Conclusions . This remote and untouched group of islands constitutes a major hawksbill turtle rookery both nationally and globally. While anthropogenic impacts and predation are low year round, climate change threatens to skew hatchling sex ratios, eventually leading to an increase in hatchling mortality.

Implications . Additional ground-based surveys are required to refine the accuracy of population estimates presented in this study. Given the paucity of data in the region, we recommend this island group off Groote Eylandt be used as a population-monitoring index site for the eastern Arnhem Land hawksbill turtle breeding aggregation.

Context . Distance sampling is used to estimate abundance for several taxa, including pronghorn (Antilocapra americana). Comparisons between population estimates derived from quadrat sampling and distance sampling suggest that distance sampling underestimates pronghorn density, likely owing to violations of the critical assumption of distance sampling that all pronghorn within the innermost distance band (A band; nearest to the aircraft) are detected.

Aims . We sought to rigorously test the assumption that all pronghorn clusters are detected within the innermost distance band by applying a double-observer approach to an established pronghorn aerial-survey protocol. Additionally, we evaluated potential effects of cluster size, landscape composition and seat position (front seat versus rear) on the probability of detection.

Methods . We conducted aerial line-transect distance-sampling surveys using independent, paired observers and modelled the probability of detection with mark–recapture distance-sampling (MRDS) analysis techniques that explicitly estimate the probability of detection for pronghorn clusters in the innermost distance band. We compared density estimates produced by the MRDS analysis with those produced by multiple-covariate distance sampling (MCDS), a method that assumes complete detection for clusters on the transect line.

Key results . We identified violations of the assumption that all clusters within the innermost distance band were detected, which would contribute to proportional biases in density estimates for analysis techniques that assume complete detection. The frequency of missed clusters was modest from the front-seat position, with 45 of the 47 (96%) clusters in the A band detected. In contrast, the frequency of missed clusters was more substantial for the rear position, from which 37 of 47 (79%) clusters in the A band were detected. Further, our analysis showed that cluster size and landscape composition were important factors for pronghorn sightability.

Conclusions . When implementing standard survey methodologies, pronghorn aerial-line transect surveys underestimated population densities. A double-observer survey configuration allowed us to quantify and correct for the bias caused by the failure of observers to detect all pronghorn clusters within the innermost distance band.

Implications . Population monitoring programs should incorporate double-observer validation trials to quantify the extent of bias owing to undetected clusters within the innermost distance band realised under typical survey conditions. Wildlife managers can improve the precision of pronghorn aerial line-transect surveys by incorporating cluster size and measures of landscape composition and complexity into detection models without incurring additional survey costs.

Context . The role of disturbance and its exclusion is fundamental to the conservation of threatened species.

Aims . We used the habitat accommodation model as a framework to investigate the importance of forest disturbance for the endangered Hastings River mouse, Pseudomys oralis, focusing on timber harvesting.

Methods . Our study comprised two separate surveys. We resurveyed old survey sites (n = 24) where the species was originally recorded as either present (logging excluded) or absent (subsequently logged). A second survey targeted trapping in high-quality habitat stratified by different times since logging. Finally, we analysed a 15-year trapping dataset targeting P. oralis to assess associations with co-occurring species.

Key results . The resurvey of old sites resulted in 12 P. oralis individuals being trapped, compared with 46 individuals in original surveys. Substantial declines were observed over time in transects where logging was excluded (60–82% decline), whereas there was little change at transects where P. oralis was not previously trapped and that were subsequently logged. The second survey yielded 27 P. oralis captures at post-logging sites assessed as high quality. Occupancy was very high (ψ = 0.93 ± 0.21) in transects logged 7–15 years ago and was 60% less in transects where logging was excluded for 35–45 years (ψ = 0.37 ± 0.22), whereas occupancy in transects logged 2–6 years ago was intermediate. This pattern of higher occupancy in logged areas was mirrored for the mean number of P. oralis trapped per transect. Ordination of habitat data showed an association of P. oralis with heath, mat-rushes and logs, whereas rats (Rattus and Melomys) were associated with ferns and shrubs. Camera traps revealed low background levels of predator presence. A negative exponential relationship was found between probability of occupancy of P. oralis and rat abundance from a 15-year trapping dataset (44 275 trap-nights), suggesting that rats may compete with P. oralis.

Conclusions . Our results supported the habitat accommodation model and suggested that disturbance is likely to influence the persistence of P. oralis. However, an interaction between predation and loss of cover from high-frequency disturbance (fire or intense grazing) cannot be excluded as a key threat.

Implications . Disturbance should be incorporated into the management of some species. Adaptive monitoring is recommended to assess alternative management regimes.

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 . Introduced mammalian predators have been responsible for population declines in native prey species around the world. Many conservation programs rely on control or eradication of introduced mammalian predators, but the impact of environmental variation on the efficacy of this approach is rarely documented.

Aims . The present paper describes (1) the impact of introduced European foxes (Vulpes vulpes) on breeding Australian pelicans (Pelecanus conspicillatus) in South Australia and (2) the responses of both species to a fox-eradication program using a before-after-impact framework.

Methods . The impact of foxes on breeding Australian pelicans was studied on a near-shore island. An index of fox abundance and direct measurements of breeding pelicans and mortality of pelican eggs and young were compared before foxes were established on the island, while foxes were resident and during a fox-eradication program. A path analysis was used to explore the causal relationships between fox abundance and other potential covariates (e.g. rainfall) on breeding pelicans.

Key results . Before foxes were established on the island, the number of breeding pelicans grew and egg mortality was low. While foxes were resident, the number of breeding pelicans fell and egg mortality rose. This was followed by an increase in the number of breeding pelicans and a decrease in egg mortality during a fox-eradication program. While foxes had a clear impact on egg mortality, a period of low rainfall also occurred while foxes were resident. The path analysis showed an interaction among rainfall, size of the pelican breeding population and the impact of foxes. In drought years, fewer pelicans bred and foxes were a major cause of nest abandonment when they entered pelican breeding colonies to prey on eggs.

Conclusions . These results confirmed that foxes can be an important predator of ground-nesting, colonial waterbirds, and showed that the impact of foxes may be higher in drought years when prey populations are low.

Implications . The present study suggests that an increase in the incidence of droughts as a result of climate change may increase the impact of introduced predators on drought-sensitive waterbirds and raises the possibility of focussing predator-control efforts during droughts, as periods of particular risk to colony-breeding waterbirds.

Deer are among the world’s most successful invasive mammals and can have substantial deleterious impacts on natural and agricultural ecosystems. Six species have established wild populations in Australia, and the distributions and abundances of some species are increasing. Approaches to managing wild deer in Australia are diverse and complex, with some populations managed as ‘game’ and others as ‘pests’. Implementation of cost-effective management strategies that account for this complexity is hindered by a lack of knowledge of the nature, extent and severity of deer impacts. To clarify the knowledge base and identify research needs, we conducted a systematic review of the impacts and management of wild deer in Australia. Most wild deer are in south-eastern Australia, but bioclimatic analysis suggested that four species are well suited to the tropical and subtropical climates of northern Australia. Deer could potentially occupy most of the continent, including parts of the arid interior. The most significant impacts are likely to occur through direct effects of herbivory, with potentially cascading indirect effects on fauna and ecosystem processes. However, evidence of impacts in Australia is largely observational, and few studies have experimentally partitioned the impacts of deer from those of sympatric native and other introduced herbivores. Furthermore, there has been little rigorous testing of the efficacy of deer management in Australia, and our understanding of the deer ecology required to guide deer management is limited. We identified the following six priority research areas: (i) identifying long-term changes in plant communities caused by deer; (ii) understanding interactions with other fauna; (iii) measuring impacts on water quality; (iv) assessing economic impacts on agriculture (including as disease vectors); (v) evaluating efficacy of management for mitigating deer impacts; and (vi) quantifying changes in distribution and abundance. Addressing these knowledge gaps will assist the development and prioritisation of cost-effective management strategies and help increase stakeholder support for managing the impacts of deer on Australian ecosystems.