Context. In the vicinity of the western Rajaji Tiger Reserve, a significant rise in conflicts between humans and leopards has occurred. These conflicts have resulted in a substantial number of human deaths, with 60% attacks resulting in deaths over a 4-year period.

Aims. This study aims to examine any potential connection among the non-breeding tigers, leopards, prey, humans and the increased occurrence of conflicts.

Methods. To address this objective, we conducted an analysis to evaluate the density of leopards, as well as their spatial and temporal behaviour with respect to tigers, prey and humans through on-site habitat use, circular statistics, diel-overlap as well spatial niche breadth and spatial-niche overlap.

Key results. Our findings showed one of the highest leopard-density estimates (excluding cubs) (mean ± s.e.) of 23.7 ± 4.8 per 100 km². When examining on-site habitat use by leopards, we found three variables that had a negative influence, namely, human presence, slope, and the presence of tigers. The presence of a large prey (sambar) had a positive influence. Leopards, exhibiting the highest spatial-niche breadth, demonstrated a small overlap with both tigers and humans, while displaying a significant diel overlap with sambar. The niche overlap was notably high with sambar, but very low with humans and tigers.

Conclusions. Although tigers locally created a zone of spatial and temporal avoidance, at the population level the leopards experienced a surge in numbers in response to the reduced tiger numbers, indicated by their high density. This could be a cause of high leopard movement into nearby human settlements. This unique scenario could have contributed to conflict.

Implications. Understanding the coexistence among different species and the impact of transient animals is crucial to develop effective management strategies to mitigate conflict. This approach would facilitate and ensure the long-term survival of diverse large carnivores in the tropical forests of southern Asia through sustained support for conservation from local communities.

Context. Feral cats are responsible for the decline and extinction of species globally. Predation by feral cats is identified in Australian legislation as a key threatening process. However, clear guidance to local land managers on feral cat management techniques and their impacts, limitations and potential costs can be difficult to find.

Aims. In this study, feral cat management experts from around Australia identified available management techniques and their average environmental, social, and economic impact for different ecoregions and land-use types.

Methods. We convened a 1-day structured elicitation workshop with 19 experts and five facilitators. Experts identified the techniques used for feral cat management; the effectiveness, impact, and cost of each method; and the key knowledge gaps associated with feral cat management. Facilitators aided in the design and format of the workshop, led the discussion at each stage and collated the results.

Key results. Experts identified the following 10 techniques currently used in Australia: aerial baiting; ground baiting; leghold trapping; cage trapping; shooting; tracking with detector dogs; tracking by Indigenous Rangers; habitat modification; resource modification; and exclusion fencing. In general, experts highlighted that permits, legislation and scale of application constrained many of these techniques. Aerial baiting was considered the most effective technique for reducing feral cat populations in natural and production systems. Cage trapping, shooting, or tracking with detector dogs were considered more effective in residential areas. For all techniques, efficacy estimates varied according to the following three broad vegetation structural regions: (1) deserts and xeric shrublands; (2) forests and woodlands; and (3) grasslands, savannas and shrublands. Techniques considered to have the lowest social tolerance and highest impact to non-target native species included aerial baiting, ground baiting and leghold trapping. Techniques considered to have high social tolerance and low impact on non-target species included tracking by Rangers, tracking with detector dogs, and habitat and resource modification.

Conclusions. Estimates of management action efficacy differ among land-use types and at least three vegetation structural regions. However, social licence, logistic and legislative constraints are the key drivers of the availability of methods for these areas.

Implications. Feral cat management programs should consider how program strategy can be prioritised on the basis of technique availability, region of use and expected impact.

Context. Overabundant ungulate populations frequently cause ecological and economic damage and are difficult to control. Sustained culling efforts at El Palmar National Park have largely reduced wild boar (Sus scrofa) numbers and damage but have failed to halt the ever-increasing abundance of axis deer (Axis axis) for undefined reasons. Multi-year camera-trap surveys indicated a mismatch between deer core activity and the usual timing of hunting sessions.

Aim. We used the spatial and temporal forms of Taylor’s law (TL, a power relationship between the sample mean and sample variance) to test whether overnight hunting sessions are more effective for culling axis deer and wild boar than are daytime sessions, and assessed whether they modify ungulate harvest composition.

Methods. We implemented a quasi-experimental trial (i.e. ‘experiments in which units are not assigned to conditions randomly’), including nine alternating blocks of four to seven hunting sessions each (overnight or daytime) in which an average of 42 hunter groups performed controlled shooting over bait from fixed elevated blinds, retrieved, sexed, weighed and measured all quarry.

Key results. The relationship between the mean and variance of ungulate crude catch per hunting-party session and crude catch per unit effort (CPUE, where effort is measured in hunting-party hours) by hunting shift satisfied the spatial and temporal TL. On average, axis deer catch was 2.39–2.61 times greater in overnight than in daytime sessions, whereas CPUE indices were 1.54–1.73 times greater. For wild boar, overnight sessions returned catches similar to (0.94–1.03×), and a significantly lower CPUE (0.63–0.67×) than for daytime sessions. The harvest indices were substantially aggregated in daytime sessions only, and were consistently skewed towards yearlings or subadults and males, especially among adult deer. Overnight sessions culled proportionally more adults and more pregnant hinds and sows than did daytime sessions, and significantly heavier deer and wild boar males.

Conclusions. Overnight sessions were substantially more effective for culling deer than were daytime sessions, and selected for individuals with greater fitness. Stage- and male-skewed harvest most likely explains the steady population growth of axis deer despite increasing hunting pressure over a decade.

Implications. Adjusting the schedule of hunting sessions to time intervals of peak ungulate activity substantially increased the efficiency of management efforts in terms of removal rates and reproductive value of the culled specimens.

Context. Predators typically select prey on the basis of their availability and traits such as body size, speed, camouflage and behaviour that influence ease of capture. Such selectivity, particularly by invasive predators, can disproportionately affect the conservation status of prey. Control of top-order predators can also trigger trophic cascades if subordinate predators have different prey preference.

Aims. We aimed to document prey selectivity of feral cats by comparing their diet with prey availability over a 27-year study in an Australian desert.

Methods. Stomach-content and demographic data were recorded from 2293 feral cats, showing 3939 vertebrate prey. These were compared with vertebrate-prey availability estimated from 224,472 pitfall-trap nights, 9791 Elliott-trap nights and opportunistic sampling that accumulated 9247 small mammal and 32,053 herptile records. Potential bird availability was assessed through 2072 quantitative counts amounting to 29,832 bird records. We compared cat selectivity among species, guilds, and physical and behavioural traits of potential prey.

Key results. Prey guild selectivity from two quantitative subsets of these data indicated that cats preferentially selected medium-sized rodents, snakes and ground-nesting birds over other prey guilds, and also preyed extensively on rabbits, for which selectivity could not be assessed. Species that froze or responded defensively to predators were less favoured than were prey that fled, including fast-evading species. Species inhabiting dunes were hunted more frequently relative to their abundance than were closely related species on stony plains.

Conclusions. The size, habitat preference and response to predators of potential prey species affect their targeting by feral cats.

Implications. Our results assist assessment of risk to wildlife species from cat predation and suggest that cat control will trigger changes in the relative abundance of prey species depending on their size, habitat use and behaviour.

Context. Canid-pest ejectors (CPEs) offer a compromise between broadscale free-baiting programs that can have non-target impacts and more target-specific methods such as trapping and shooting, which are inefficient across larger scales. CPEs target wild canids, such as red foxes (Vulpes vulpes) and wild dogs (Canis spp.). However, there are situations where red fox control is required, but the risk to non-target canids, such as dingoes and other dogs, prevents the use of broadscale baiting.

Aims. We field-trialled and refined a collar for the CPE that was designed to allow red foxes to trigger CPEs, but prevent dingoes and medium–large-sized dogs from doing so.

Methods. We deployed uncollared and collared CPEs paired with camera-traps across two study areas in central Australia, and assessed which taxa triggered CPEs and whether the activity rates, behaviour and CPE triggering rates of five taxa (red foxes, wild dogs, feral cats (Felis catus), corvids (Corvus spp.), and varanids (Varanus spp.)) differed between CPEs with and those without collars.

Key results. With a simple modification to our original collar design, a red fox was able to trigger collared CPEs. Collared CPEs were triggered by wild dogs when they were set with the bait head 1 cm below the rim of the collar, but not when they were set with the bait head at 2 cm below the rim. Uncollared CPEs were triggered by wild dogs (97.03% of triggers), red foxes (1.98%) and corvids (0.99%). Activity rates of the study taxa towards CPEs did not differ between collared and uncollared CPEs. However, behavioural analyses suggested that red foxes and wild dogs showed more caution around collared CPEs.

Conclusions. We present proof-of-concept that deploying CPEs inside a collar increases the target specificity of this device by excluding wild dogs, while allowing red foxes to access the bait head. However, our data suggest that the addition of a collar may reduce interaction rates of red foxes and wild dogs with CPEs.

Implications. The collared CPE provides a control method for red foxes that reduces the risk to dingoes and other medium–large-sized dogs and may allow for greater landholder participation in red fox management.

Context. Freshwater ecosystems rank among the most threatened environments on Earth. Monitoring aquatic and semi-aquatic species is vital to informing conservation of freshwater ecosystems. However, many semi-aquatic mammals can be difficult to detect with conventional survey methods.

Aims. We aimed to identify the most effective survey method for detecting an Australian semi-aquatic mammal, the rakali (Hydromys chrysogaster).

Methods. We compared rakali detection rates among camera-trapping, live-trapping and visual surveys, and tested the influence of camera angle, trap proximity to water and time of survey, across the Yanco Creek system in southern New South Wales.

Key results. Nocturnal spotlight surveys were the most effective method for detecting rakali, with most observations occurring while individuals were foraging or swimming in the water. Camera traps facing a floating platform and cage traps mounted on floating platforms performed better than those deployed on land. Downward-facing camera traps detected rakali three times more often than did forward-facing cameras. Trapping rakali was unreliable, with the species detected at fewer than half of the sites where presence was confirmed via visual observation and camera traps. For species absence to be determined with 95% confidence, 2–4 weeks of nightly trapping is required, compared with six nights of visual surveys or 12 nights for a platform-facing camera. Morning visual surveys were largely ineffective because of predominantly nocturnal rakali activity and difficulty in detecting signs in creek environments.

Conclusions. The likelihood of detecting rakali can be maximised through the use of nightly spotlighting and deployment of baited camera traps focussed on platforms or natural resting areas within a water body.

Implications. Understanding the effectiveness of each method is essential for developing species-appropriate protocols for population monitoring. Our findings present suitable options to be further explored among the 100-plus small (<1 kg) semi-aquatic mammals worldwide that share similar behaviours and characteristics to the rakali, many of which are threatened or data deficient.

Context. Ecological surveillance monitoring typically targets multiple taxonomic groups by using standardised sampling across large spatial scales. Although surveillance monitoring confers advantages over hypothesis-driven monitoring in its broad taxonomic and spatial scope, the approach has been criticised for its disconnect from ecological management and failure to provide insights on the drivers of ecological change

Aims. To assess the adequacy of a plot-based general fauna-monitoring program for sampling reptiles as indicators of ecosystem health in a semi-arid upland region of the Northern Territory, Australia.

Methods. We surveyed reptiles at 90 sites, stratified between major landform and vegetation types, and using standard fauna-sampling methods, across the 2568 km² Tjoritja National Park in the MacDonnell Ranges. We compiled a full inventory of the reptile fauna of the study area and identified species with potential utility as ecological indicators. We then used single-season occupancy models and power analyses to evaluate the adequacy of sampling for detecting potential future changes in occupancy.

Key results. We detected 57 of the 68 reptile species known from the protected area, 17 of which are potentially useful indicators of ecological health, mostly related to fire management. There was insufficient power to detect moderate (50%) future changes in reptile occupancy for all but the single most detected species. For the two ecological indicator species with sufficient detections for occupancy modelling, a positive association with a keystone structure (dense spinifex grass) was confirmed. However, increasing detection probability or the number of surveys would result in only minor improvements in power to detect occupancy change in these species.

Conclusions. Although reptiles are potentially useful indicators of ecological health, particularly in relation to fire regimes, the number of sites required to detect future changes in reptile occupancy by using standardised plot-based monitoring in this protected area is prohibitively high.

Implications. Our results suggest that once ecological associations are understood, monitoring ecological health remotely by using techniques such as fire-scar mapping to track proportions of long-unburnt vegetation should be considered over labour-intensive surveillance monitoring for reptiles. Targeted monitoring of threatened and other reptile species of conservation or cultural concern may also be warranted.

Context. Animal-borne devices can affect animal survival, reproduction, and behaviour through both the addition of weight and bulk and the direct effects of initial and subsequent capture. Researchers commonly employ a general rule of thumb that weight of the device must be less than 5% of bodyweight for terrestrial animals; however, this threshold has little empirical basis.

Aims. We evaluated the effects of environmental variables, repeated capture, and weight of animal-borne devices on bodyweight in free-ranging feral cats.

Methods. We recaptured feral cats at varying frequencies, wearing GPS and/or VHF collars that ranged from 0.29% to 4.88% of bodyweight, and recorded change in cat weight over time.

Key results. Collar weight as a percentage of bodyweight was not a significant predictor of feral cat weight change. Rather, change in bodyweight was best described by a negative relationship with an increasing temperature and number of captures, and a positive relationship with time since collar attachment.

Conclusions. Capture had a significant influence on feral cat weight but collar weights up to 5% of bodyweight did not significantly contribute to weight loss. However, the absence of control cats without collars hindered definitive conclusions on the effect of collar weight on cat weight change.

Implications. Researchers should space capture and handling events more than 30 days apart to reduce effects of weight loss from capture and handling. Researchers should also consider increasing collar weight and reducing frequency of capture (where collars are less than 5% of bodyweight), particularly if cat bodyweight is a parameter of interest.