Context. Free-roaming domestic cats are a widespread invasive species, occurring throughout the globe in urban and rural environments alike. However, robust estimates of cat occupancy and abundance, especially in rural, agricultural landscapes, are largely unknown.

Aims. To estimate cat occupancy and abundance within forested habitat in a fragmented agricultural region of Indiana, USA.

Methods. Free-roaming cats in 55 forest patches were captured from 2004 to 2010 to assess the effects of landscape attributes on cat occupancy probabilities. During 2009–10 abundance of cats in each habitat patch was estimated based on natural markings of captured individuals.

Key results. Across the entire study (2004–10) cats in 50 of the 55 patches were detected, but detections varied temporally and spatially. Average occupancy probability was estimated at Ψ = 0.773 (s.e. = 0.109), and detection probability was estimated as P = 0.204 (s.e. = 0.012). Distance to human structures and forest patch isolation both were found to negatively influence cat occupancy. In total, 57 individual cats were captured in 2009 and 55 in 2010, when unique individuals were distinguished. Across all forest patches, average cat abundance was n = 1.08 in 2009 and n = 0.91 in 2010, ranging from 0 to 7 among sampled patches.

Conclusions. Overall, the distribution of free-roaming cats across a rural agricultural landscape varied temporally and was associated with proximity to human structures and the proximity of other forest habitat. Similarly, abundance was found to vary spatially and temporally.

Implications. The findings suggest free-roaming cats are widespread throughout agricultural ecosystems, but their distribution is dynamic and non-random. Additionally, the potential for cats to impact native fauna inhabiting remnant forest patches is high in fragmented agricultural ecosystems due to the concentration of native species utilising these patches. Further research is needed to determine the effects free-roaming cats are having on native species in human-dominated, rural ecosystems, and what conservation measures might be implemented to best mitigate any impacts.

Context. Relative abundance indices of wildlife can be scaled to give estimates of absolute abundance. Choice of scaling parameter depends on the data available and assumptions made about the relationship between the index and absolute abundance. Predation-mechanics theory suggests that a parameterisation involving the rate of successful search, s, will be useful where the area searched is unknown. An example arises during fox culling on shooting estates in Britain, where detection and cull data from gamekeepers using a spotlight and rifle are available, and can potentially be used to understand the population dynamics of the local population.

Aims. We aimed to develop an informative prior for s for use within a Bayesian framework to fit a fox population-dynamics model to detection data.

Methods. We developed a mechanistic model with a rate of successful search parameter for the gamekeeper–fox system. We established a mechanistic prior for s, using Monte Carlo simulation to combine relevant information on its component factors (detection probability, observer field of view and speed of travel). We obtained empirical estimates of s from a distance-sampling study of fox populations using similar survey methods, and used these as data in a Bayesian model to develop a mechanistic–empirical prior. We then applied this informative prior within a state–space model to estimate fox density from fox-detection rate on four estates.

Key results. The mechanistic–empirical prior for the rate of successful search was lognormally distributed with a median of 2.01 km² h^–1 (CV = 0.56). Underlying assumptions of the parameterisation were met. Local fox-density estimates obtained using informative priors closely reflected regional density.

Conclusions. A mechanistic understanding of the search process leading to fox detections by gamekeepers, and the use of Bayesian models, allowed the use of diverse sources of information to develop an informative prior for s that was useful in estimating fox density from detection data.

Implications. Careful use of prior knowledge within a Bayesian modelling framework can reduce uncertainty in population estimates derived from index data, and lead to improved management decisions. The mechanistic approach we have used will have parallel applications in many other contexts.

Context. Direct observations of animals are the most reliable way to define their behavioural characteristics; however, to obtain these observations is costly and often logistically challenging. GPS tracking allows finer-scale interpretation of animal responses by measuring movement patterns; however, the true behaviour of the animal during the period of observation is seldom known.

Aims. The aim of our research was to draw behavioural inferences for a lioness with a hidden Markov model and to validate the predicted latent-state sequence with field observations of the lion pride.

Methods. We used hidden Markov models to model the movement of a lioness in the Kruger National Park, South Africa. A three-state log-normal model was selected as the most suitable model. The model outputs are related to collected data by using an observational model, such as, for example, a distribution for the average movement rate and/or direction of movement that depends on the underlying model states that are taken to represent behavioural states of the animal. These inferred behavioural states are validated against direct observation of the pride’s behaviour.

Key results. Average movement rate provided a useful alternative for the application of hidden Markov models to irregularly spaced GPS locations. The movement model predicted resting as the dominant activity throughout the day, with a peak in the afternoon. The local-movement state occurred consistently throughout the day, with a decreased proportion during the afternoon, when more resting takes place, and an increase towards the early evening. The relocating state had three peaks, namely, during mid-morning, early evening and about midnight. Because of the differences in timing of the direct observations and the GPS locations, we had to compare point observations of the true behaviour with an interval prediction of the modelled behavioural state. In 75% of the cases, the model-predicted behaviour and the field-observed behaviour overlapped.

Conclusions. Our data suggest that the hidden Markov modelling approach is successful at predicting a realistic behaviour of lions on the basis of the GPS location coordinates and the average movement rate between locations. The present study provided a unique opportunity to uncover the hidden states and compare the true behaviour with the inferred behaviour from the predicted state sequence.

Implications. Our results illustrated the potential of using hidden Markov models with movement rate as an input to understand carnivore behavioural patterns that could inform conservation management practices.

Context. The Australian cotton industry has committed to (1) understanding the biodiversity value of remnant native vegetation on cotton farms, (2) funding independent, evidence-based assessments of the industry’s sustainability and environmental performance, and (3) investing in research that reports against recognised sustainability indicators.

Aims. The present study reports the results of an industry-wide survey to benchmark bird diversity in native vegetation on cotton farms spanning a 1260-km north–south subcontinental gradient from Central Queensland (Qld) to Southern New South Wales (NSW).

Methods. Between September and November 2014, birds were sampled twice on separate days in 2-ha quadrats (20 min per census) in eight remnant vegetation types as well as in native revegetation at 197 sites on 60 cotton farms spread across the principal cotton-growing zones (Central Qld, Border Rivers, Macquarie and Southern NSW) in inland eastern Australia.

Key results. We recorded 185 bird species in remnant and planted native vegetation on cotton farms. Species richness of bird communities declined from north to south. Bird community composition was similar in the three southern zones, differing somewhat in the north. The most frequent species were large (>60 g), readily detected landbirds common in agricultural districts, but 26 of the 53 extant species of conservation concern in the study region were also recorded, including 16 species of declining woodland birds. Bird composition, abundance, richness and diversity differed among the nine native vegetation types, with maximal and minimal bird abundance and diversity metrics recorded in river red gum-dominated riparian vegetation and grassland respectively.

Conclusions. Each remnant vegetation community had a generally distinct bird assemblage, indicating that all vegetation types contribute to regional biodiversity in cotton-growing zones in inland eastern Australia. Appropriate on-farm management of all remnant and planted native vegetation will assist regional biodiversity conservation.

Implications. For the Australian cotton industry to meet its stated environmental responsibilities, growers should be encouraged to prioritise the conservation management of remnant, riparian and planted native vegetation on cotton farms and the monitoring of bird species as an indicator of regional biodiversity response.

Context. With limited resources for wildlife management and conservation, it is vital that the effectiveness of management programs is maximised and costs reduced. Koala populations need to be reduced in locations where they are locally overabundant and over-browsing their food trees. Subcutaneous contraceptive implants containing levonorgestrel are currently used to control koala fertility to assist in reducing population densities. Dependent young are caught with their mothers, so are also available for contraception.

Aims. The overall aim was to investigate whether the effectiveness of koala contraception programs can be improved by administering levonorgestrel implants to female young along with their mothers. This was achieved by: (1) determining if implanting females before sexual maturation affects their fertility, growth and pouch development; and (2) developing a stage-structured population growth model to compare two management scenarios.

Methods. Juvenile female koalas (11–17 months old) were treated with either a control (n = 5) or 70 mg levonorgestrel implant (n = 5). Koalas were caught every 4 to 6 weeks for 15 months, then every 3 to 12 months for 5 years. Koalas were weighed and head length measured. Pouches were checked for young. Pouch development was assessed as a proxy for sexual maturation. A stage-based population model simulating koala population growth was developed to compare different management scenarios: no treatment; treatment of adults only; and treatment of adults plus their dependent young.

Key results. Levonorgestrel implants prevented births with no effect on growth, survival or timing of sexual maturation. Population growth simulations indicate that treating dependent young with their mothers results in earlier population reduction.

Conclusions. The treatment of prepubertal female koalas with levonorgestrel implants is a safe and effective method that increases the effectiveness of koala contraception programs.

Implications. Development of novel strategies may provide opportunities to increase the efficiency and cost-effectiveness of management programs with constrained resources.

Context. Researchers and managers often use DNA analysis and remote photography to identify cryptic animals and estimate abundance. Remote video cameras are used less often but offer an increased ability to distinguish similar-looking individuals as well as to observe behavioural patterns that cannot be adequately captured with still photography. However, the use of this approach in species with minimally distinguishing marks has not been tested.

Aims. To determine the utility and accuracy of distinguishing characteristics of American black bears, Ursus americanus, observed on remote video for identifying individuals in an open population.

Methods. We compared individuals identified on video with individuals and their sex identified by DNA analysis of hairs collected from hair traps visited by the bears.

Key results. We found that remote video could be used to determine the number of male and female black bears sampled by the video cameras. Specifically, we matched 13 individual bear genotypes with 13 video identifications, one genotype for each individual. We correctly matched ∼82% of video identifications with all 38 genotypes collected from hair traps.

Conclusions. We demonstrated that distinguishing characteristics of a cryptic animal in remote video can be used to accurately identify individuals. Remote video complements genetic analysis by providing information about habitat use and behaviour.

Implications. When remote video cameras can be used to identify individuals, a wealth of other information will subsequently be obtained. Multi-year video-based studies can show sex ratios, and relative physical condition; shed light on fine-scale habitat use, such as when and where animals feed and what they eat; and display social interactions and rare behaviours.

Context. Measuring a mammal’s body mass has importance in understanding nutritional condition, reproductive biology and ecology. It can be impractical for a researcher to measure the body mass when equipment needed to weigh individuals is inadequate or unavailable.

Aims. The purpose of this study was to develop a model to accurately estimate the body mass of hunter-harvested Florida white-tailed deer (Odocoileus virginianus osceola, Odocoileus virginianus seminolus) based on the relationship between scale mass, sex and standard age and morphometric measurement predictor variables easily obtainable in the field.

Methods. An information-theoretic approach was used to evaluate simple and multiple linear regression models with 67% of the data, and the best model in the set was validated using the remaining 33%.

Key results. Chest girth was the best single predictor of body mass. A global model including sex, age, age² and body length variables was better supported than chest girth alone, and subspecies information did not contribute significantly to the body-mass–predictor-variable relationship. The best model explained 98.5% of the variation in body mass as follows: body mass (kg) = –18.41 + 6.53 × sex (0 = female, 1 = male) + 5.04 × age (year) – 0.49 × age² (year²) + 4.76 × 10⁻³ × chest girth² (cm²) + 0.12 × body length (cm). The 95% confidence interval on the bias of the estimated body mass of the best model was –0.50 to 0.59 kg. The difference between estimated and scale body mass was –0.04 kg ± 0.28 (s.e.).

Conclusions. Individuals maintained a similar proportion of body mass to predictor variables, and differences between the observed and estimated body mass of model applied to the validation dataset were not significant.

Implications. The validated body-mass-estimation model presented will enable accurate estimates of the body mass of white-tailed deer in cases where standard age and morphometric measurements are available, but the individuals were not weighed. These results provide a basis to formulate and parameterise body-mass-estimation models for other white-tailed deer subspecies and populations. Without the need for specialised equipment, the body-mass-estimation model can be used by personnel involved in white-tailed deer research, management and sport hunting to assess trends in individual and population health in support of this species’ conservation.

Context. European rabbits have a great impact on native vegetation and small vertebrates in Australia. Rabbits consume vegetation and promote invasive plants and invasive predators, and compete directly and indirectly with native animals suppressing those populations.

Aims. We explored the changes in small native vertebrates and invertebrates following the removal of rabbits.

Methods. Warren ripping was undertaken on a property in south-western Queensland at four sites and the results of pitfall trapping were compared with four nearby paired control sites. Invertebrates and small mammals were counted in pitfall traps, and bird surveys were conducted in all treatment and control sites.

Key results. Following a rabbit-control program, we observed a four-fold increase in the number of dunnarts trapped in treatment plots, whereas no change was observed in control plots. The spring following the rabbit-control program also saw an increase in some lizards in treatment plots.

Conclusions. The presence of rabbits in arid-zone Australia can suppress native animal populations.

Implications. Many species of small native mammals and lizards rely on food sources that fluctuate greatly with environmental conditions. The presence of rabbits altering the landscape, supporting introduced predators, reducing vegetation and, therefore, insects, adds increased pressure for insectivorous species. Rabbit control through warren ripping in arid-zone Australia is an effective method to reduce rabbit numbers, and allowed for an increase in small vertebrates in treated areas.

Context. Biological resource use represents the most common direct threat to biodiversity. Despite this, there is a paucity of comprehensive and overarching data relating to the biological resource use. The global aquarium trade encompasses millions of individual live fishes representing thousands of marine and freshwater species traded on an annual basis. The lack of specific data systems for recording information where fish are exported or imported has resulted in limited accessible trade data. An evaluation of the data-reporting frameworks presently employed by countries engaged in the aquarium trade is warranted to better understand the means by which comprehensive data on the aquarium trade can be made more accessible.

Aims. This study examines the data-reporting framework of The Australian Government Department of Agriculture and Water Resources (DAWR) used to collate aquarium fish import data, and its capacity to inform on the aquarium trade biodiversity imported to Australia.

Methods. Aquarium import records from 2010–16 were provided by DAWR and used to determine the quantity of individual fishes and consignments imported to Australia. The potential biodiversity of imports was determined from the Australian Government’s List of Permitted Live Freshwater/Marine Fish Suitable for Import 2018 (Number 69, F2017C00079), the legislative document identifying species permitted import to Australia for the aquarium trade. Species permitted import were cross-referenced with the International Union for Conservation of Nature (IUCN) Red List to address whether the Australian aquarium trade is importing threatened species.

Key results. A total of 10 320 consignments encompassing more than 78.6 million aquarium fishes were imported to Australia between 2010 and 2016. A total of 4628 species of fishes were permitted import to Australia for the aquarium trade with 73 of the marine species (2.0%) and 81 of the freshwater species (7.5%) found to be threatened with some degree of extinction risk. The data-reporting framework for aquarium fish imports offered limited capacity to taxonomically differentiate imports and only 12.5% of all aquarium fishes imported could be identified to species.

Conclusions. The aquarium fish import records provided by DAWR had limited taxonomic resolution and, consequently, limited capacity to contribute to an improved understanding of the biodiversity imported to Australia for the aquarium fish trade. While more detailed information is available than is presently collated by DAWR, the availability of this information is constrained by the laws around protected information and the resources available to DAWR.

Implications. Accessible, detailed information on aquarium fish imports is necessary to support comprehensive research capable of addressing threats to biodiversity loss from the aquarium trade. To this end, the means by which Australian aquarium import data can be reported at greater taxonomic resolution under the existing legislative and resource restraints should be explored further.