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Globally, many wild deer populations are actively studied or managed for conservation, hunting, or damage mitigation purposes. These studies require reliable estimates of population state parameters, such as density or abundance, with a level of precision that is fit for purpose. Such estimates can be difficult to attain for many populations that occur in situations that are poorly suited to common survey methods. We evaluated the utility of combining camera trap survey data, in which a small proportion of the sample is individually recognizable using natural markings, with spatial mark–resight (SMR) models to estimate deer density in a variety of situations. We surveyed 13 deer populations comprising four deer species (Cervus unicolor, C. timorensis, C. elaphus, Dama dama) at nine widely separated sites, and used Bayesian SMR models to estimate population densities and abundances. Twelve surveys provided sufficient data for analysis and seven produced density estimates with coefficients of variation (CVs) ≤ 0.25. Estimated densities ranged from 0.3 to 24.6 deer km−2. Camera trap surveys and SMR models provided a powerful and flexible approach for estimating deer densities in populations in which many detections were not individually identifiable, and they should provide useful density estimates under a wide range of conditions that are not amenable to more widely used methods. In the absence of specific local information on deer detectability and movement patterns, we recommend that at least 30 cameras be spaced at 500–1,000 m and set for 90 days. This approach could also be applied to large mammals other than deer.

Lead toxicity threatens scavenging wildlife globally. To allow inexpensive measurement of long-term lead exposure from archived wildlife tissues, portable X-ray fluorescence (XRF)1devices have been validated to measure lead concentrations in bone samples from bird species. In this study, we evaluated the efficacy of portable XRF for hair lead measurement in a specialist mammalian scavenger, the threatened Tasmanian devil (Sarcophilus harrisii). We attempted to first validate the method by analyzing relatively large (∼1.0 g) hair samples from 39 deceased animals initially with XRF, and then with inductively coupled plasma mass spectrometry (ICP-MS) (validation study). We then measured lead concentrations via XRF only in a further 61 hair samples taken from live devils trapped in a plantation forestry landscape, where devils may scavenge on browsing marsupials that are regularly culled using lead ammunition (plantation study). Portable XRF measures of hair lead levels were positively correlated with ICP-MS values (R2= 0.95), although the relationship was weak at low lead concentrations. In the validation study, 95% of sampled Tasmanian devils had relatively low lead levels (≤ 3 mg/kg), but the remaining two animals showed considerably elevated lead levels (> 15 mg/kg), suggesting that harmful long-term lead exposure can occur in this species. In the plantation study, lead levels were comparable to those found in the hair of mammals in other studies, though a higher proportion (11%) of devils showed levels > 3 mg/kg than in the validation study, suggesting devils may have higher exposure to lead in a landscape subjected to regular culling of browsing mammals. Our results suggests that portable XRF is a promising emerging technology, and after some refinement, may allow non-invasive real-time measurement of lead concentrations in the hair of mammals.

Context Helicopter-based shooting has been widely used to kill deer in Australasia, but the animal welfare outcomes of this technique have not been evaluated. Aim To assess the animal welfare outcomes of helicopter-based shooting of deer in Australia by quantifying the fates of deer seen and shot at, the duration of procedures and the number and location of bullet wounds in deer. Methods Three deer control operations were assessed. These operations targeted: (1) chital deer (Axis axis) in Queensland, (2) fallow deer (Dama dama) in Australian Capital Territory and (3) fallow deer in New South Wales. For each operation, an independent veterinarian conducted ante-mortem (i.e. from the helicopter as shooting occurred) and post-mortem (i.e. from the ground after shooting had ceased) observations. The ante-mortem data were used to estimate the proportion of deer seen that were shot, chase time (CT), time to insensibility (TTI) and total time (TT; CT + TTI). The numbers and locations of bullet wounds were recorded post-mortem. Key results Ante-mortem and post-mortem observations were performed for 114–318 and 60–105 deer, respectively, in the three operations. Shots were fired at 69–76% of deer that were observed. Median CT ranged from 73 to 145 s. Median TTI ranged from 17 to 37 s and median TT ranged from 109 to 162 s. The mean number of bullet wounds per deer ranged from 1.43 to 2.57. Animal welfare outcomes were better in the two fallow deer operations than in the chital deer operation. In both fallow deer operations, most deer were shot multiple times and at least once in the head or thorax. In contrast, chital deer were shot fewer times and less often in the head or thorax, and non-fatal wounding was observed. Conclusions The best animal welfare outcomes were achieved when helicopter-based shooting operations followed a fly-back procedure and mandated that multiple shots were fired into each animal. Implications Animal welfare outcomes for helicopter-based deer shooting in Australia could be improved with a national-level standard operating procedure requiring helicopters to fly back over shot animals and repeatedly shoot animals in the head or thorax.

Context Safe and effective capture methods are crucial for improving our understanding and management of many wildlife species. The adaptation of established capture methods to novel situations requires critical evaluation because differences in environmental conditions and species’ susceptibility to trauma and capture myopathy can produce unexpected outcomes. Helicopter net-gunning has been a valuable tool for capturing wild deer in New Zealand and the Americas, but there are no practical records of its use in Australia and only one report of it being used to capture three fallow deer (Dama dama) elsewhere. Aims The present study aimed to evaluate the feasibility of a helicopter-based net-gun capture technique for wild fallow deer by quantifying the efficacy of the technique and the frequency of injuries and deaths. Methods We captured fallow deer over two 3-day operations at a 135 km2 site in eastern Australia. We collected data on operational efficiency and variables expected to affect animal health and welfare, such as injuries and the duration of stressful procedures. We used GPS tracking collars with an accelerometer and a mortality-sensing function to monitor post-release survival and activity of fallow deer. Key results In total, 127 deer were targeted for capture, with nets fired at 64 deer (50%) and 27 deer captured (21%). Mortality within 30 days of capture was zero. Mean chase time was 2 min 46 s and mean total time from start of chase until release was 11 min 19 s. No animals were severely injured or euthanased, but hyperthermia was observed in 33% of captured animals. Conclusions Helicopter net-gunning was an effective and safe method for capturing wild fallow deer when compared with alternative methods. Implications We recommend that researchers consider using helicopter net-gunning to capture fallow deer in Australia and elsewhere, and other deer species in Australia.

Deer (Cervidae) are key components of many ecosystems and estimating deer abundance or density is important to understanding these roles. Many field methods have been used to estimate deer abundance and density, but the factors determining where, when, and why a method was used, and its usefulness, have not been investigated. We systematically reviewed journal articles published during 2004–2018 to evaluate spatio-temporal trends in study objectives, methodologies, and deer abundance and density estimates, and determine how they varied with biophysical and anthropogenic attributes. We also reviewed the precision and bias of deer abundance estimation methods. We found 3,870 deer abundance and density estimates. Most estimates (58%) were for white-tailed deer (Odocoileus virginianus), red deer (Cervus elaphus), and roe deer (Capreolus capreolus). The 6 key methods used to estimate abundance and density were pedestrian sign (track or fecal) counts, pedestrian direct counts, vehicular direct counts, aerial direct counts, motion-sensitive cameras, and harvest data. There were regional differences in the use of these methods, but a general pattern was a temporal shift from using harvest data, pedestrian direct counts, and aerial direct counts to using pedestrian sign counts and motion-sensitive cameras. Only 32% of estimates were accompanied by a measure of precision. The most precise estimates were from vehicular spotlight counts and from capture–recapture analysis of images from motion-sensitive cameras. For aerial direct counts, capture–recapture methods provided the most precise estimates. Bias was robustly assessed in only 16 studies. Most abundance estimates were negatively biased, but capture–recapture methods were the least biased. The usefulness of deer abundance and density estimates would be substantially improved by 1) reporting key methodological details, 2) robustly assessing bias, 3) reporting the precision of estimates, 4) using methods that increase and estimate detection probability, and 5) staying up to date on new methods. The automation of image analysis using machine learning should increase the accuracy and precision of abundance estimates from direct aerial counts (visible and thermal infrared, including from unmanned aerial vehicles [drones]) and motion-sensitive cameras, and substantially reduce the time and cost burdens of manual image analysis.

In response to the health threats posed by toxic lead to humans, scavenging wildlife and the environment, there is currently a focus on transitioning from lead-based to lead-free bullets for shooting of wild animals. We compared efficiency metrics and terminal ballistic performance for lead-based and lead-free (non-lead) bullets for aerial shooting of wild pigs (Sus scrofa) in eastern Australia. Ballistic testing revealed that lead-based and lead-free bullets achieved similar performance in precision and muzzle kinetic energy (E0) levels (3337.2 J and 3345.7 J, respectively). An aerial shooting trial was conducted with wild pigs shot with one type of lead-based and one type of lead-free bullets under identical conditions. Observations were made from 859 shooting events (n = 430 and 429 respectively), with a sub-set of pigs examined via gross post-mortem (n = 100 and 108 respectively), and a further sub-set examined via radiography (n = 94 and 101 respectively). The mean number of bullets fired per pig killed did not differ greatly between lead-based and lead-free bullets respectively (4.09 vs 3.91), nor did the mean number of bullet wound tracts in each animal via post-mortem inspection (3.29 vs 2.98). However, radiography revealed a higher average number of fragments per animal (median >300 vs median = 55) and a broader distribution of fragments with lead-based bullets. Our results suggest that lead-based and lead-free bullets are similarly effective for aerial shooting of wild pigs, but that the bullet types behave differently, with lead-based bullets displaying a higher degree of fragmentation. These results suggest that aerial shooting may be a particularly important contributor to scavenging wildlife being exposed to lead and that investigation of lead-free bullets for this use should continue.

Management of the domestic cat (Felis catus) relies on community members adopting appropriate management practices toward both companion and unowned (stray, free-living) animals. Getting people to ...

Owners of free-ranging domestic cats (Felis catus) are under increasing pressure to keep their pet contained within their house or yard, in an effort to reduce adverse impacts on cat welfare, ecosystem biodiversity and neighbourhoods. We conducted a randomised online experiment to assess the effectiveness of two persuasive messages to encourage cat owners to contain their pets. A total of 512 Australian cat owners, who currently do not contain their cats, were randomly assigned to view one of three short video messages: one framed to highlight the negative impact of cats' on wildlife and biodiversity ('wildlife protection' frame), one framed to highlight the health and safety benefits of keeping cats contained ('cat benefit' frame), and a control message focused on general information about cats ('neutral' frame). We assessed the impact of these video messages on two post-treatment outcome variables: (1) the intention of owners to contain their cat; and (2) the adoption of containment practices, based on a 4-week follow-up survey. Mediation analysis revealed both the 'wildlife protection' and 'cat benefit' messages increased owners' motivation to contain their cat and their beliefs that they could effectively contain their cat to achieve the desired outcomes (response efficacy). In turn, higher levels of motivation and response efficacy predicted increased cat containment intentions and increased adoption of cat containment. In addition, the response efficacy effects of the 'cat benefit' message were strengthened by the cat owner's bond to their pet, suggesting audience segmentation may improve the effectiveness of interventions. Implications for future intervention development are discussed.

Natural resource management agencies in many countries take advantage of recreational hunting to manage the impacts or abundance of mammal populations that damage biodiversity or environmental, economic, or social values. In Australia, public lands are increasingly being made available for recreational hunters to pursue introduced mammals that can cause substantial damage to important resources. There is fervent debate over the role that recreational hunting might play in controlling introduced mammals in Australia, and scant evidence to build management strategies upon. In this review, we combine information from Australia and elsewhere in a systematic examination of the potential for recreational hunting to contribute to the control of introduced mammals on public lands in Australia. We examine the traits of introduced mammal species and populations, geographical settings, hunters, and management agencies to propose situations where hunting might be most useful, and suggest how current practice could be improved. We find there is insufficient evidence to support or disprove arguments that contemporary recreational hunting programs are effective at controlling introduced mammal populations on public lands. Moreover, current hunting management programs offer little potential for clarifying the situation or optimizing the value of recreational hunting as a pest animal control tool. To resolve this problem, we outline a framework of competing models and diagnostic criteria for assessing the effects of recreational hunting on introduced mammal populations. We contend that hunting will continue to be an under-utilized and over-politicized resource until management strategy is informed by transparent monitoring based on rational strategic objectives that provide mutual benefits to hunters and public resource managers.

Context Ground-based shooting is widely used in management programs aiming to alleviate the impacts of invasive or overabundant wildlife populations. However, evaluations of individual shooting operations have shown variable results, and the effectiveness of ground-shooting as a population-management intervention has not been systematically examined. Aims Our review aimed to (1) assess the efficacy of shooting as a population management tool, and (2) identify commonalities among studies that will help managers identify situations where ground-shooting is most likely to be effective. Methods We systematically reviewed the literature to identify studies involving ground-shooting. From each study, we collated information about operational objectives, target taxa, geographic context, type of shooter used, effort, effectiveness, and use of additional control tools. Key results Most studies had no a priori quantifiable objectives. However, 60% of the 64 case studies produced a detectable reduction in population density and/or damage. The most common type of operation used unpaid or commercial harvest-oriented shooters to reduce herbivore density or damage. Only 30% of the operations that used volunteer shooters or recreational hunters achieved their objectives. Target taxa, geographic area or integration of shooting with other population-control methods had no detectable effect on the effectiveness of shooting operations. Common factors that hindered the effectiveness of shooting operations included immigration of target species from adjacent areas (n=13), decreasing effort from shooters as the target population declined (n=7) and selective harvesting (n=7). Conclusions Ground-based shooting can be an effective management tool for overabundant wildlife populations, but many shooting operations did not achieve a notable decrease in animal abundance or damage. The source of failure could often be attributed to an inability to remove a sufficient proportion of the population to cause a population decline. Implications Managers contemplating using ground-based shooting to reduce the impacts or density of wildlife populations should (1) carefully consider whether this is a suitable management tool to achieve the desired outcomes, (2) establish clear objectives that aim to meet defined outcomes and allow for continuous improvement, and (3) ensure that operations are sufficiently resourced to achieve and maintain those objectives.

An understanding of the factors that drive inter-population variability in home-range size is essential for managing the impacts of invasive species with broad global distributions, such as the feral domestic cat (Felis catus). The assumption that home-range sizes scale negatively with landscape productivity is fundamental to many spatial behaviour models, and inter-site variation in landscape productivity has often been invoked to explain the vast differences in feral cat home-range sizes among different regions. However, the validity of this explanation has not been tested or described. We used regression models to examine the ability of remotely sensed landscape productivity data, average body weight and population density to explain differences in the size of feral cat home ranges estimated across a diverse collection of sites across the globe. As expected for a solitary polygynous carnivore, female cats occupied smaller home ranges in highly productive sites, and range sizes of male cats scaled positively with those of females. However, the relationship between range size and productivity broke down at highly seasonal sites. Home-range size also scaled negatively with population density, but there was no clear relationship with average body weight. The relationships we describe should be useful for predicting home-range sizes and for designing effective feral cat control and monitoring programmes in many situations. More generally, these results confirm the importance of landscape productivity in shaping the spatial distribution of solitary carnivores, but the nature of the relationship is more complicated than is often appreciated.

The roles of the 37 species in the family Canidae (the dog family), are of great current interest. The Gray Wolf is the largest canid and their roles in food webs are much researched, as are those of Domestic Dogs, Coyotes and Red Foxes. Much less is known about the other canid species and their ecological roles. Here we describe general food web theory and the potential application of network theory to it; summarise the possible roles of predators in food webs; document the occurrence, diet and presumed functions that canids play in food webs throughout the world; give case studies of four threatened canid species of top, middle and basal trophic positions and six anthropogenically affected species; and identify knowledge limitations and propose research frameworks necessary to establish the roles of canids in food webs. Canids can be top-down drivers of systems or responsive to the availability of resources including suitable prey. They can be affected anthropogenically by habitat change, lethal control and changes to basic resource availability. They can be sustainable yield harvesters of their indigenous prey or passengers in complex ecosystems, and some are prey of larger canids and of other predators. Nevertheless, the roles of most canids are generally poorly studied and described, and some, e.g. Gray Wolves, Coyotes and Australian dingoes, are controversial. We advocate mensurative and experimental research into communities and ecosystems containing canids for a quantitative understanding of their roles in food webs and consequent development of better management strategies for ecosystems.

Predator-odor-based repellents have benefits as humane, non-lethal management tools that may reduce the need for lethal control in some areas. Macropods (such as kangaroos and wallabies) are iconic Australian native marsupials; however, some are considered important rangeland pests, and their presence in the urban and peri-urban environment often results in conflict. The management of these macropods is a contentious and volatile issue. We evaluated lion (Panthera leo), Sumatran tiger (P. tigris sumatrae), and dingo (Canis lupus dingo) fecal odors as short-term odor-based repellents for wild eastern grey kangaroos (Macropus giganteus) and red-necked wallabies (M. rufogriseus). These odors were used to ‘protect' highly palatable food sources; with any food not consumed (residue) collected and weighed each day. Trials were conducted at Long Grass Nature Reserve in Queensland, Australia from 9–29 January 2009. Both eastern grey kangaroos and red-necked wallabies relocated a minimum of 100 m away from the food station treated with lion odors on the first day of the trial. As a result of this spatial shift, more food was consumed at the control food stations than at any food station treated with predator odors (regardless of predator). In particular, eastern grey kangaroos never fed from a single predator-odor food station. An increase in vigilance behaviors was observed for both macropod species, and red-necked wallabies were more likely to exhibit vigilance behaviors than feeding behaviors at predator odor food stations. There was no difference in food residue between any predator odors and these food stations were only visited on the first day of the study. Use of predator fecal odors may repel macropods from highly palatable food sources, and predator fecal odors also may be useful for macropod relocation. © 2014 The Wildlife Society.

Summary Many camera trap surveys aiming to detect the effects of management actions on pest animal populations are not as useful as they could be, because they do not produce informative results. We used mixed effects models, signed ranks tests and occupancy models to examine changes in the activity and occurrence of European red fox (Vulpes vulpes L.) in areas subjected to repeated fox management operations. In agricultural land, mixed effects models identified a decline in fox activity after baiting in 1 year, but not the next. Occupancy models revealed a decrease in fox occurrence in a National Park following control operations. These methods, combined with appropriate survey designs, could greatly enhance the value of many pest animal surveys conducted by management agencies.

Abstract ContextWe examined the effectiveness of camera traps to monitor the success of a feral-cat (Felis catus) and fox (Vulpes vulpes) reduction program near Ravensthorpe, Western Australia. AimsTo determine whether camera traps are an effective tool to measure a reduction in the abundance of F. catus and V. vulpes at a local scale. MethodsIn all, 201 Foxoff® baits (i.e. 1080) were laid along the edge of unsealed tracks for each of three periods (i.e. opened 13–15 May 2017, Period 1 closed 29–31 May 2017, Period 2 closed 12–13 June 2017, Period 3 closed 25–26 June 2017), and 98 bait sites were monitored by camera traps during each period. In addition, 150 baited cage traps were deployed to catch F. catus for the same three periods. Vulpes vulpes and F. catus were also shot in the adjacent paddocks before traps were opened and during the laying of traps and bait replacement. We used the first 13 days of camera-trapping data for each period to examine whether there was a significant reduction in V. vulpes and F. catus. Key resultsCamera traps recorded a significant reduction in V. vulpes images, but knock-down with Foxoff® baits was not as effective as in other programs, and there was no change in the measured abundance of F. catus. Numerous baits were taken and not recorded by camera traps. Multiple V. vulpes moved past or investigated, but did not take baits and a V. vulpes was recorded regurgitating a bait. ConclusionsCamera traps were not effective for recording bait-take events. Vulpes vulpes knock-down was low and slow compared with other studies, did not reflect the number of baits taken and Foxoff® baits appeared unpalatable or unattractive to many V. vulpes. ImplicationsCamera traps did not record a high proportion of bait-take, appeared to be insensitive to small changes in fox and cat abundance and Foxoff® baits were less effective in reducing the abundance of V. vulpes than in other studies.

Context Feral cats (Felis catus) impact the health and welfare of wildlife, livestock and humans worldwide. They are particularly damaging where they have been introduced into island countries such as Australia and New Zealand, where native prey species evolved without feline predators. Kangaroo Island, in South Australia, is Australia’s third largest island and supports several threatened and endemic species. Cat densities on Kangaroo Island are thought to be greater than those on the adjacent South Australian mainland, based on one cat density estimate on the island that is higher than most estimates from the mainland. The prevalence of cat-borne disease in cats and sheep is also higher on Kangaroo Island than the mainland, suggesting higher cat densities. A recent continental-scale spatial model of cat density predicted that cat density on Kangaroo Island should be about double that of the adjacent mainland. However, although cats are believed to have severe impacts on some native species on the island, other species that are generally considered vulnerable to cat predation have relatively secure populations on the island compared with the mainland. Aims The present study aimed to compare feral cat abundance between Kangaroo Island and the adjacent South Australian mainland using simultaneous standardised methods. Based on previous findings, we predicted that the relative abundance of feral cats on Kangaroo Island would be approximately double that on the South Australian mainland. Methods Standardised camera trap surveys were used to simultaneously estimate the relative abundance of feral cats on Kangaroo Island and the adjacent South Australian mainland. Survey data were analysed using the Royle–Nichols abundance-induced heterogeneity model to estimate feral cat relative abundance at each site. Key results Cat abundance on the island was estimated to be over 10 times greater than that on the adjacent mainland. Conclusions Consistent with predictions, cat abundance on the island was greater than on the adjacent mainland. However, the magnitude of this difference was much greater than expected. Implications The findings show that the actual densities of cats at local sites can vary substantially from predictions generated by continental-scale models. The study also demonstrates the value of estimating abundance or density simultaneously across sites using standardised methods.

Globally, wild or feral pigs Sus scrofa are a widespread and important pest. Mitigation of their impacts requires a sound understanding of those impacts and the benefits and limitations of different management approaches. Here, we review published and unpublished studies to provide a synopsis of contemporary understanding of wild pig impacts and management in Australia, and to identify important shortcomings. Wild pigs can have important impacts on biodiversity values, ecosystem functioning and agricultural production. However, many of these impacts remain poorly described, and therefore, difficult to manage effectively. Many impacts are highly variable, and innovative experimental and analytical approaches may be necessary to elucidate them. Most contemporary management programmes use lethal techniques to attempt to reduce pig densities, but it is often unclear how effective they are at reducing damage. We conclude that greater integration of experimental approaches into wild pig management programmes is necessary to improve our understanding of wild pig impacts, and our ability to manage those impacts effectively and efficiently.

The lack of variance estimates constrain the utility of abundance indices calculated from camera-trap data. We adapted a General Index model, which allows variance estimation, to analyze camera- trap observations of feral pigs (Sus scrofa) for population monitoring in a tropical rainforest. We tested whether the index would respond to population manipulation, and found that it decreased by 57% following removal of 24 pigs and remained low in the following period. Our method is useful for monitoring other large animals in difficult landscapes, and the model can be used to enhance the value of existing data sets. 2011 The Wildlife Society.

Small mammals often moderate their foraging behaviour in response to cues indicating a high local predation risk. We assessed the ability of cues associated with a high predation risk to reduce the consumption of bait by non-target small mammal species in a tropical rainforest, without inhibiting bait-take by feral pigs (Sus scrofa). The illumination of feeding stations with a low power light source caused small mammals to reduce their foraging intensity on sunflower seeds mixed through sand by 25% (P 0.05 for all treatments). We conclude that site illumination was an effective method of selectively deterring small mammals from consuming feral pig baits in our study region, but had no effect on consumption of those baits by pigs.

The efficacy of vertebrate pest control in complex faunal communities can be compromised by adverse impacts on non-target species. We present a five-step framework to guide the design of pest control programmes to overcome this constraint. The model consists of: (i) selection of the most appropriate basis for control; (ii) identification of opportunities to prevent non-target species from interacting with control activities; (iii) classification of non-target species by dissimilarity to the target pest; (iv) use of a recognition systems approach to identify further differences between pests and non-target species; and (v) experimental evaluation of prototype control methodologies. Application of the framework to the problem of feral Pig (Sus scrofa) control in the tropical forests of the Daintree region in north Queensland identified six design features which, if successfully evaluated and implemented, could allow the implementation of strategic, sustained Pig control using poison baits where it has previously been unacceptable.

Free-roaming domestic cats, Felis catus, are a major public nuisance in neighbourhoods across the world, and have been linked to biodiversity loss and a host of community health problems. Owners who let their cats roam, also place their cats at risk of serious injury. One management strategy that is gaining considerable support involves encouraging cat owners to contain their pets within their property. Contemporary behaviour change models highlight the importance of identifying drivers and barriers that encourage and discourage target behaviours such as cat containment. Results from a random dial phone survey of 356 cat owners in northern Tasmania identified four distinct cat containment profiles: owners who contained their cat all the time, owners who only contained their cat at night, owners who sporadically contained their cat with no set routine, and owners who made no attempt to contain their pet. Our results indicated that cat-owners' decisions to contain or not contain their cats were guided by a range of factors including owners' beliefs about their ability to implement an effective containment strategy and their views about the physical and psychological needs of their cats. The results are discussed in terms of improving the behavioural effectiveness of cat containment interventions by selecting appropriate behavioural change tools for the identified drivers and barriers, and developing targeted engagement strategies and messaging.

Introduction. By virtue of their structural and floristic diversity, the riparian corridors of Australia’s savanna woodlands provide unique resources and conditions for the savanna fauna and are characterized by greater vertebrate diversities than the surrounding woodlands (Williams 1994). Riparian vegetation is particularly susceptible to disturbances associated with livestock grazing and invasive species. For example, the highly invasive Rubber Vine (Cryptostegia grandiflora Roxb. Ex R.Br.) is common in tropical Queensland riparian systems where it frequently forms extensive, dense thickets. Degradation of riparian vegetation by heavy livestock grazing and associated infestation by Rubber Vine and other weeds has been implicated in the decline of individual bird species and the impoverishment of vertebrate assemblages generally (Rowley 1993; Kutt & Skull 1995). The fencing of riparian zones is commonly considered to be a cost-effective method of controlling stock access and associated disturbance to ecologically important riparian areas. Riparian fencing may also help to improve long-term pasture productivity by allowing managers to selectively rest these areas during critical periods of pasture development (Burrows & Butler 2001). A riparian fencing project initiated by Landcare groups in Queensland’s northern Burdekin Rangelands provided the opportunity to examine the effects of fencing, patch widths and associated environmental conditions on riparian avifauna.

Author(s): Bengsen, Andrew J.; Gentle, Matthew N.; Mitchell, James L.; Pearson, Hayley E.; Saunders, Glen R. | Abstract: Feral or free-ranging pigs have been a problem in Australia since the first years of European settlement, and they now occur in a wide range of habitat types throughout much of the continent. Feral pigs impact environmental, agricultural, and cultural resources, but they can also have commercial value from harvesting and recreational or subsistence hunting. It has been difficult to quantify many of the adverse impacts of feral pigs. Consequently, most management programs aim to mitigate actual, potential, or perceived impacts that have been inferred from observational studies and anecdotes, untested retroductive hypotheses, or observations generated from outside of Australia. Lethal control to reduce population density is the most common form of management, and it is often applied as a form of insurance, rather than to mitigate specific, measurable impacts. We suggest that future management programs should aim to quantify the effects of management actions on pig populations and the vulnerable resources that are the basis of real management objectives. There are important ethical and practical reasons for this approach, which should in turn enhance the efficiency and efficacy of management programs and help to ensure continued public and government support for ongoing mitigation of the feral pig problem.

The risk of non-target species being harmed by pest management activities can be a major impediment to animal control being implemented. This problem is particularly acute in complex faunal communities, where the pest occurs with functionally-similar species. Here, we present a framework for developing target-specific pest management tools for complex communities that helps managers reduce the risk of non-target species impacts. We applied the framework to the problem of poison baiting for feral pig control in the tropical rainforests of north-eastern Australia, and identified several potential methods to reduce adverse baiting impacts on non-target species. We evaluated the target-specificity of different baits and bait presentation methods using camera traps and sandplots to monitor animal-bait interactions in the field. As predicted using the framework, making baits available only at night prevented bait take by diurnal species, and bait burial substantially reduced bait consumption by nonfossorial species. The illumination of bait sites also reduced the foraging intensity of small non-target mammals, without inhibiting bait take by feral pigs. Two putative auditory repellents for small mammals were ineffective. Temporal variation in bait take by pigs and other species was unpredictable, and we were unable to exploit seasonally-variable factors to further enhance targetspecificity. The use of a starch-rich vegetable bait, rather than an omnivore bait, prevented bait take by dingoes and improved bait take by feral pigs. The use of a light plastic container to cover this bait prevented bait take by small omnivores when an uncovered free-feed was also provided. This latter baiting method renders nocturnal distribution, bait burial, and site illumination unnecessary, and provides a simple, target-specific baiting protocol that will allow effective feral pig control in the region for the first time. Our field results demonstrate the usefulness of the framework in our study site. The framework is similarly suitable for developing target-specific methods for delivering other chemical or biological agents to wildlife or pest populations, or for developing other pest control tools such as traps. The framework awaits further evaluation in other complex faunal communities.

Context Automatically activated cameras (camera traps) and automated poison-delivery devices are increasingly being used to monitor and manage predators such as felids and canids. Maximising visitation rates to sentry positions enhances the efficacy of feral-predator management, especially for feral cats, which are typically less attracted to food-based lures than canids. Aims The influence of camera-trap placement and lures were investigated to determine optimal monitoring and control strategies for feral cats and other predators in two regions of semi-arid South Australia. Methods We compared autumn and winter capture rates, activity patterns and behaviours of cats, foxes and dingoes at different landscape elements and with different lures in three independent 6 km × 3 km grids of 18 camera-trap sites. Key results Neither visual, olfactory or audio lures increased recorded visitation rates by any predators, although an audio and a scent-based lure both elicited behavioural responses in predators. Cameras set on roads yielded an eight times greater capture rate for dingoes than did off-road cameras. Roads and resource points also yielded highest captures of cats and foxes. All predators were less nocturnal in winter than in autumn and fox detections at the Immarna site peaked in months when dingo and cat activity were lowest. Conclusions Monitoring and management programs for cats and other predators in arid Australia should focus on roads and resource points where predator activity is highest. Olfactory and auditory lures can elicit behavioural responses that render cats more susceptible to passive monitoring and control techniques. Dingo activity appeared to be inversely related to fox but not cat activity during our monitoring period. Implications Optimised management of feral cats in the Australian arid zone would benefit from site- and season-specific lure trials.

Context Poison-baiting programs coordinated among neighbouring landholders should provide the most effective and efficient tool for controlling fox (Vulpes vulpes) populations and impacts in mixed agricultural landscapes, but the effects of such programs on fox mortality and abundance have not been well described. Aims This study aimed to describe the effects of coordinated fox-control programs conducted by landholders on fox mortality and abundance, and to evaluate the likely impacts of reduced landholder participation rates on the proportion of the fox population exposed to baits. Methods The effects of two baiting programs on fox abundance were evaluated using camera-trap surveys and abundance-induced heterogeneity models. The proportion of foxes surviving baiting was estimated by tracking the fate of 19 GPS-collared individuals. The benefits of coordinated baiting were examined using simulated scenarios based on local fox movements and bait distribution patterns. Key results Examination of actual and simulated fox home ranges demonstrated that coordinated baiting increases exposure of the target population to baits. However, 69% of foxes captured on properties that later baited were estimated to have survived the baiting period. Camera-trap surveys across baited and unbaited properties showed no detectable decline in average fox abundance after baiting. Conclusions Coordinated baiting increases the proportion of the fox population encountering baited properties. However, high fox survival and the absence of detectable declines in abundance after baiting showed that even well coordinated baiting programs can produce suboptimal results if many of the foxes using baited properties fail to locate and ingest lethal baits. Implications Baiting programs aiming to reduce the density and impacts of foxes in agricultural landscapes should strive to maximise participation among neighbours. Programs may also benefit from taking steps to improve bait-encounter and consumption rates within properties, for example, by deploying baits at sufficient intensity to provide all foxes with access to at least one bait within their short-term home range. Future research should aim to identify optimal baiting intensities within properties and conditions to maximise bait uptake.

Context Effective feral-cat (Felis silvestris catus) management requires a sound understanding of the ways cats use their environment. Key characteristics of landscape use by cats vary widely among different regions and different conditions. Aims The present study aimed to describe the most important characteristics of landscape use by feral cats on a large, human-populated island, and to use this information to guide the development of feral-cat management programs. Methods We used GPS tracking collars to record the movements of 13 feral cats at two sites on Kangaroo Island, South Australia, for between 20 and 106 days. We described home-range extents by using local convex hulls, and derived management suggestions from examination of home-range and movement data. Key results Median feral-cat home range was 5.11 km2, and this did not differ between sexes or sites. Cats at a fragmented pastoral site tended to favour woody vegetation over open paddocks, but habitat preferences were less clear at a bushland site. Cats that preferentially used treelines at the pastoral site were almost twice as likely to be recorded close to a tree-line junction as expected. Conclusions Control programs for feral cats on Kangaroo Island should deploy control devices at a density no less than 1.7 devices km–2. Spatial coverage should be as large as practicable or repeated frequently. Infrequent programs covering small areas can be expected only to provide short-term reductions in cat abundance. Implications The information gained from the present study will contribute to the development of strategic sustained management plans for feral cats on Kangaroo Island. The principles from which we inferred management guidelines are applicable to other regions and species.

Context The mitigation of feral pig (Sus scrofa) impacts in north Queensland’s World Heritage tropical rainforests is constrained by the lack of an effective and target-specific poison baiting method. Aims This study aimed to determine whether easily implemented bait presentation methods or seasonal variation in bait acceptability could be used to selectively reduce the consumption of feral pig baits by non-target species. Methods We exposed manufactured feral pig baits to pigs and non-target species in the field, and compared bait encounter, sampling and consumption rates for different functional groups of species among three different types of bait presentation and composition. We then exposed baits under different seasonal conditions and related bait encounter and consumption by different functional groups to seasonally variable phenomena. Key results Shallow burial greatly reduced bait consumption by most non-target species, but not dingoes (Canis lupus dingo). Nocturnal bait distribution and seasonal baiting were less useful. Pigs showed substantial seasonal variation in physiological condition, suggesting that pigs should be more susceptible to consuming novel foods, such as baits, after periods of low rainfall. However, few pigs consumed the manufactured baits used in this study. Conclusions Manufactured baits are not currently suitable for widespread use in the region. However, shallow burial should provide an effective method of reducing non-target bait-take if baits can be made more attractive and acceptable to pigs and less acceptable to dingoes. Implications Future efforts to enable effective feral pig control in the region should focus on developing baiting materials that are more attractive to pigs and unappealing to dingoes.

Context The ability to monitor changes in population abundance is critical to the success of pest animal management and research programs. Feral cats (Felis catus) are an important pest animal, but current monitoring techniques have limited sensitivity or are limited in use to particular circumstances or habitats. Recent advances in camera-trapping methods provide the potential to identify individual feral cats, and to use this information to estimate population abundances using capture–mark–recapture (CMR) methods. Aims Here, we use a manipulative study to test whether camera-trapping and CMR methods can be used to estimate feral cat abundances. Methods We established a grid of infrared cameras and lure stations over three pastoral properties on Kangaroo Island, Australia, for 15 days. We then reduced the population abundance with an intensive trapping program and repeated the camera survey. We estimated population abundances using robust design CMR models, and converted abundance estimates to densities using home-range data from GPS tracking. We also calculated relative abundance indices from the same data. Key results The CMR methods produced credible estimates of the change in population abundance, with useful confidence intervals, showing a statistically identifiable population decline from at least 0.7 cats km–2 before trapping down to 0.4 cats km–2 after trapping. The indexing method also showed a statistically identifiable decrease in abundance. Conclusions Camera-trapping and CMR methods can provide a useful method for monitoring changes in the absolute abundance of feral cat populations. Camera-trap data may also be used to produce indices of relative abundance when the assumptions of CMR models cannot be met. Implications These methods are widely applicable. The ability to reliably estimate feral cat abundances allows for more effective management than is generally available.