Context. Feral pigs (Sus scrofa) have a wide global distribution that includes large parts of Australia and New Zealand. There is concern about the impacts of feral pigs on above- and below-ground flora and fauna, but little is known about their habitat use and feeding activity in temperate rainforests.

Aims. We evaluated the importance of abiotic and biotic variables hypothesised to influence seasonal and annual feral pig habitat use and feeding activity in a montane conifer–angiosperm rainforest in Te Urewera, North Island, New Zealand.

Methods. We used a grid of 25 remote-camera locations to collect feral pig images in a 100-ha area during the winters and summers of 2010 and 2011. Plant composition, solar radiation and soil fertility variables were determined for each camera-image area. Multiseason, multistate occupancy models and information-theoretic methods were used to evaluate how these variables related to feral pig occupancy and feeding.

Key results. Feral pigs occupied more camera locations in summer than in winter, and detection probabilities increased if piglets were present and with increasing soil phosphorus (P). Piglets were detected only in summer, and their detection probability increased with increasing soil P. The probability of detecting feral pigs feeding also increased with soil P and was higher in 2010 than 2011.

Conclusions. Feral pigs selected locations with high soil P, probably because those sites had more food than did locations with low soil P. Mast fruiting of tawa (Beilschmiedia tawa) has been hypothesised to increase feral pig recruitment, and the higher detection probability of piglets in summer 2010 followed a heavier tawa fruit fall.

Implications. Our study highlighted the usefulness of camera traps and occupancy models for understanding seasonal and annual dynamics of cryptic ungulate species in remote, rugged forests, and suggests that the impacts of feral pigs will be greatest in areas of high soil P following widespread tawa masting.

Context.Many shorebirds are threatened by human-caused disturbance. For snowy plovers, disturbance within nesting habitats has been implicated as a major contributing factor in their population decline through deleterious effects on breeding success. Very little is known about site specificity of disturbance from human activities for this species.

Aims.We examined the disturbance of incubating snowy plovers to determine if nesting shorebirds within one breeding population exhibited site-specific patterns of disturbance from human activities.

Methods.We recorded flush (i.e. flight or escape from a perceived threat) distances and time spent off the nest following approach by a single person on Sanibel and Cayo Costa Islands, two islands in south-west Florida that differ in daily human visitation, and by a person walking a dog on Sanibel. We used a Bayesian model framework to determine effects of location and approach type on flush distance and time spent off of the nest.

Key results.Birds nesting on Sanibel flushed at shorter distances from a solitary person without a dog than did birds nesting on Cayo Costa, but spent similar amounts of time off of nests following a flush. On Sanibel, nesting birds also flushed at significantly greater distances and spent significantly more time off of nests when flushed by a person walking a dog rather than by a person alone.

Conclusions.Within a population, nesting snowy plovers exhibit site- and stimulus-dependent patterns of disturbance. The intraspecific variation falls within the range of variation recorded among species of birds studied elsewhere. Although we cannot determine causation, we suggest habituation to human activities from a combination of high beach usage, smaller nesting exclusion zones, and narrower beach width on Sanibel compared to Cayo Costa as a likely explanation for this difference.

Implications.Set-back distances for symbolic fencing have been generalised across species and nesting locations. Our results suggest that disturbance of nesting shorebirds can be site-dependent even within one breeding population of a species. Set-back distances around shorebird nests must account for location and types of activities encountered, implying the need for more conservative implementation of set-back distances.

Context. Operations to eradicate non-native invasive predators from islands frequently put native species at risk of consuming harmful substances, such as poison bait. The incorporation of certain colours in poison-bait pellets may reduce the risk of bait consumption and, therefore, non-target mortality. Previous work indicated that birds generally avoid blue or green colours; however, there is substantial inter-specific variation in this preference, and more experimental work on species of conservation concern is needed.

Aims. We tested whether a globally threatened island endemic, the Henderson crake (Zapornia atra), which suffered substantial mortality during a rat-eradication attempt on Henderson Island in 2011, would consume fewer blue than green pellets, which were used during the previous eradication attempt.

Methods. We held 22 Henderson crakes in captivity and provided them with either blue or green non-toxic pellets for 5 days in June and July 2015. We measured consumption and used linear mixed models to evaluate whether bait colour influenced consumption.

Key results. Henderson crakes did not consume any dry pellets, and all trials were conducted with wet bait pellets. We found slightly lower consumption of blue pellets than green pellets, and substantial variation among individuals. Females (n = 17) consumed 24% less blue than green bait, whereas males (n = 5) consumed 77% less blue than green bait.

Conclusion. Henderson crakes are unlikely to consume dry pellets, and will likely consume fewer blue than green bait pellets.

Implications. We recommend that any future rat eradication on Henderson Island considers using blue rather than green baits and targets dry weather to reduce the risk of Henderson crakes consuming toxic rodenticide bait pellets.

Context. Invasions by non-native plants can alter the abundance and distribution of resources that can affect habitat quality for native animals.

Aims. We sought to understand the demographic consequences of a plant invasion on a functionally and numerically important rodent in a grassland ecosystem. Specifically, we evaluated how abundance, survival, reproductive activity and population structure of Arizona cotton rats (Sigmodon arizonae) varied across a gradient of invasion by Eragrostis lehmanniana (Lehmann lovegrass), a bunchgrass native to Africa that has invaded grasslands in North America.

Methods. Over a four-year period, we used capture–recapture methods to survey small mammals on 54 1-ha plots between 10 and 13 times. We used vegetation data collected each autumn to quantify biomass of non-native grass, total biomass and vegetation heterogeneity to characterise vegetation structure on each plot.

Key results. We captured 1344 individual cotton rats during 106 560 trap-nights across all sampling periods. In areas dominated by non-native grass, abundance of cotton rats increased 7- to 10-fold and survival increased by 117% relative to areas dominated by native grasses. In contrast, reproductive activity of adults decreased by 62% for females and 28% for males, and the proportion of adults in the population decreased by 20% in these same areas.

Conclusions. Demography of Arizona cotton rats differed markedly in areas invaded by a non-native plant relative to native grasslands, supporting the long-held idea that life histories can reflect local environmental conditions. Because distributions of many non-native plants are predicted to increase in response to future changes in natural and anthropogenic drivers, the potential breadth of these complex effects on communities of native animal is immense.

Implications. The complex variation in demographic responses across the invasion gradient suggests that it may be necessary to evaluate a suite of vital rates to fully understand the consequences of plant invasions on animals. This is especially important for species of conservation concern because single demographic parameters, which are used frequently as targets to gauge the success of conservation and management activities, could be misleading.

Context. Predation by feral cats is a key threatening process to many species of native Australian wildlife. Unfortunately, cats are difficult to capture using standard trapping techniques, limiting the potential to conduct research on their ecology and impacts.

Aims. We present an alternative capture method: remote chemical immobilisation after tracking with trained dogs. We also compare capture rates to a concurrent soft-jaw leg-hold trapping program.

Methods. We used dogs to capture cats detected by spotlighting at night, and also recaptured cats fitted with telemetry collars during the day. Cats were either bailed on the ground or treed and then hand-netted, or chemically immobilised using darts shot from a CO₂-powered dart rifle, loaded with tiletamine–zolazepam at ∼6 mg kg^–1. Factors affecting the success rate of capturing cats using dogs were assessed. Efficiency in terms of cats captured per person-hours of fieldwork were compared using trained dogs versus leg-hold trapping.

Key results. We attempted 160 cat captures using the tracking dogs with 114 of those being successful. There were no mortalities or debilitating physical injuries associated with chemical immobilisation; however, sedated cats had prolonged recoveries (>4 h). Capture success with the tracking dogs increased as the dogs gained experience. Capture success rates per person-hour of fieldwork were four times greater using spotlighting with tracking dogs than using leg-hold traps. The success rate of recaptures using dogs was 97%.

Conclusions. The use of trained tracking dogs proved an effective method for capturing feral cats. The method had a much higher success rate than live-trapping with leg-hold traps, took less effort (in terms of person-hours) and caused less physical injuries than did leg-hold traps. However, substantial setup costs and time are required, which are discussed.

Implications. Using these methods could improve efficiency and outcomes when catching feral cats, and enable more data per individual cat to be collected than otherwise.

Context. Wild yak (Bos grunniens), Tibetan wild ass (Equus kiang, also known as kiang) and Tibetan antelope (Pantholops hodgsoni, also known as chiru) have been sympatric on the Tibetan Plateau for numerous generations. There is concern over potential dietary competition among them, particularly in winter when their forage resources are scarcer, but little is known about their dietary interactions.

Aim. We aimed to determine diet composition and dietary overlap of the three ungulate species, and to assess the extent of potential dietary competition among them in order to enhance our understanding of mechanisms underlying their co-existence. We predicted that the three species would widen their choice of forages in winter (December) compared with summer (June–July), and that there would be diet segregation among them, particularly in winter when food resources were scarcer.

Methods. We collected fresh faecal samples of the three species and reference forage samples from the field during our transect line surveys in the summers of 2012 and 2013, and winter of 2012 in Arjin Shan National Nature Reserve (ANNR) of Xinjiang Province, China. Slides of faecal samples were prepared for microhistological analysis, and plant fragments in faecal samples were identified under microscope. Relative percentage frequency of diet plant species, diet breadth and dietary overlap were calculated.

Key results. The three species consumed similar forage plants, but varied greatly in their percentage use of the available forages. Wild yak mainly fed on sedges in summer and graminoids in winter, supplemented with forbs. Kiang consumed mainly forbs in summer and browse in winter, and chiru mainly fed on graminoids and forbs in summer. Wild yak had the widest choice of forages, and kiang had the narrowest one in summer, but both wild yak and kiang became less selective in their food choice in winter, resulting in higher diet breadth. The dietary overlaps among them, as represented by Pianka’s index, were generally low, ranging from 0.26 between chiru and kiang to 0.51 between wild yak and kiang. The dietary overlap between wild yak and kiang decreased from summer (0.51) to winter (0.35), suggesting an increased dietary divergence.

Key conclusion. Our study reveals that the three species are ‘opportunistic feeders’, able to cope with coarse forage resources. There is dietary segregation among them as indicated by low dietary overlap, suggesting risk of potential competition for diets. We suggest that competition may have shaped their dietary divergence, contributing to their co-existence in ANNR.

Implication. Although there is dietary segregation among the three species in ANNR, it is not possible to make definitive conclusions about interspecific competition from these results. Further studies are needed to investigate if there is spatial and habitat segregation among them, which may facilitate their dietary divergence and thus contribute further to their co-existence in ANNR. Continued efforts are also needed to monitor their population dynamics and status of forage resources in order to prevent overgrazing.

Context. There is growing recognition of the importance of animal personality in wildlife ecology and management. Individuals that differ consistently in their behaviours from others of the same population are considered to exhibit different personalities. Personality can be easily quantified with repeat tests on animals held in captivity. However, captive-based tests may not always be possible for logistical reasons and tests conducted in captivity can alter naturally occurring behaviours. Development of methods to assess personality in the field over short-term capture is an important alternative to long-term captive tests.

Aims. To develop and refine field-based tests that can be used to easily define personality traits of wild common brushtail possum (Trichosurus vulpecula), eliminating the need to bring individuals into captivity for an extended period of time.

Methods. We developed a series of short-term capture protocols to quantify personality traits of the common brushtail possum in the field, using handling-bag tests, modified open-field tests, trap-behaviour tests and release tests.

Key results. Personality traits of brushtail possums could be measured in several different ways, but refining methods was crucial to reveal traits efficiently. Behaviours related to several personality traits (boldness, docility and activity/exploration) could be measured rapidly in the field with our methods, and were repeatable over time.

Conclusions. Rapid, reliable and easy-to-perform quantification of personality of brushtail possums in the field is possible. This may sometimes be the only available option, and has advantages over long captive trials in terms of animal welfare and cost.

Implications. The present study provides a baseline for future research on the personality of common brushtail possums and its application to management and control strategies for the species.

Context. Pathogens with reservoir hosts have been responsible for most disease-induced wildlife extinctions because the decline of susceptible hosts does not cause the decline of the pathogen. The existence of reservoirs for Batrachochytrium dendrobatidis limits population recovery and conservation actions for threatened amphibians. As such, the effect of reservoirs on disease risk within host community assemblages needs to be considered, but rarely is.

Aims. In this study we aimed to determine if amphibian species co-occurring with the green and golden bell frog Litoria aurea, a declining species susceptible to B. dendrobatidis, act as alternate hosts.

Methods. We quantified B. dendrobatidis infection levels, sub-lethal effects on body condition and terminal signs of disease in amphibian communities on Kooragang Island and Sydney Olympic Park in New South Wales, Australia, where two of the largest remaining L. aurea populations persist.

Key results. We found L. aurea carried infections at a similar prevalence (6–38%) to alternate species. Infection loads ranged widely (0.01–11 107.3 zoospore equivalents) and L. aurea differed from only one alternate host species (higher median load in Litoria fallax) at one site. There were no terminal or sub-lethal signs of disease in any species co-occurring with L. aurea.

Conclusion. Our results suggest that co-occurring species are acting as alternate hosts to L. aurea and whether their presence dilutes or amplifies B. dendrobatidis in the community is a priority for future research.

Implications. For L. aurea and many other susceptible species, confirming the existence of reservoir hosts and understanding their role in community disease dynamics will be important for optimising the outcomes of threat mitigation and habitat creation initiatives for their long-term conservation.

Context. The number of teats that a female agile antechinus (Antechinus agilis) possesses effectively determines her initial litter size. In the Otway Ranges, south-eastern Australia, numerous separate populations in which all females have either six or 10 teats occur fairly close together in similar, contiguous forest at comparable altitudes and latitudes. Six-teat and 10-teat females have a similar mean mass, but the latter have a 1.7 × greater reproductive potential and so should have a greater nutritional requirement while raising young than do six-teat females. Theoretically, they could meet this requirement by occupying larger and/or more exclusive home ranges during breeding than do six-teat females do (provided that their food-resource abundance is comparable), albeit at a greater energetic cost.

Aims. The aim of the study was to determine whether 10-teat A. agilis females occupied larger and less overlapping home ranges than did six-teat females. To interpret the findings more meaningfully, it was necessary to compare food abundance and habitat characteristics in areas occupied by the two phenotypes.

Methods. The investigation was conducted in six-teat and 10-teat A. agilis areas in cool temperate forest over 22 months. Population density was determined by mark–recapture methods and arthropod prey biomass and abundance by pitfall trapping. Vegetation structure and plant-taxa abundance and diversity were determined by standard plant-survey methods. Female home-range estimates determined by radio-tracking were based on 95% minimal convex polygons (MCP) and kernel analysis. Home-range overlap was based on 80% MCP range determinations and core areas were calculated from utilisation plots.

Key results. Female population density was 2.5 × lower in exclusively 10-teat than in exclusively six-teat populations. Radio-tracked 10-teat females’ home ranges less commonly overlapped those of identified female neighbours and, on average, were 1.5 × larger than ranges of six-teat females. Food abundance and composition was similar in six-teat and 10-teat areas, but ground cover was denser and more complex in the latter areas.

Conclusions. Food-resource availability was similar in the six-teat and 10-teat phenotype areas, so the larger, and probably more exclusive, home ranges of 10-teat females could reflect greater nutritional requirements resulting from having larger litters, and account for their lower population density.

Implications. The A. agilis teat-number variation pattern in the Otways may be a rare, visible example of ongoing incipient speciation. This makes it of great scientific and conservation value and it is important to document how the phenomenon operates.

Context. Understanding population dynamics of invasive species is crucial for the development of management strategies. Feral horses (Equus caballus) are a growing problem in the Tuan–Toolara State Forest (TTSF), a coniferous plantation in south-eastern Queensland, Australia.

Aim. The population dynamics of the TTSF feral horses was not known. Therefore, the study was designed to characterise the major vital parameters of this population and, using these data, develop a long-term management plan.

Methods. The study was conducted over 3 years (2011–14) involving 522 individually identified horses. Foaling rates were used to calculate fecundity. Body fat distribution was estimated using body condition score (BCS), which reflects the nutritional, metabolic and general health of individual animals. Multi state mark–capture population models were used to estimate age-specific survival, and the Leslie age-structured projection matrix model was used to determine the annual rate at which the population increased.

Key results. The mean annual fecundity was low (0.23 ± 0.07 s.d.). The mean BCS of the population was mid-range (2.55 ± 0.51 s.d.) with adult females having lower scores than other age and gender groups. Survival estimates were consistently high (0.92–0.95) across all age groups. The average annual finite rate of population increase (λ) for the 3 years of the study was 1.09. Sensitivity analysis demonstrated that the population growth rate was almost seven times more sensitive to changes in adult survival compared with juvenile survival, and almost twice as sensitive to changes in fecundity.

Key conclusions. Population dynamics of the TTSF feral horses were comparable to other feral horse populations similarly challenged by environmental nutritional limitations.

Implications. Defining population dynamics of the TTSF feral horses permits the formulation of management goals that can be audited and adapted as required. The most effective strategy for controlling population growth in the TTSF would involve the continuing removal of substantial numbers of adult females or manipulation of survival and/or fecundity. As selective removal will likely alter the adult sex ratio and age structure of the population, ongoing assessment is necessary to minimise adverse welfare outcomes.