Several important techniques for managing wildlife rely on ballistics (the behaviour of projectiles), including killing techniques (shooting) as well as capture and marking methods (darting). Because all ballistic techniques have the capacity to harm animals, animal welfare is an important consideration. Standardised testing approaches that have allowed refinement for other physical killing and capture methods (e.g. traps for mammals) have not been applied broadly to ballistic methods. At the same time, new technology is becoming available for shooting (e.g. subsonic and lead-free ammunition) and darting (e.g. dye-marker darts). We present several case studies demonstrating (a) how basic ballistic testing can be performed for novel firearms and/or projectiles, (b) the benefits of identifying methods producing undesirable results before operational use, and (c) the welfare risks associated with bypassing testing of a technique before broad-scale application. Following the approach that has been used internationally to test kill-traps, we suggest the following four-step testing process: (1) range and field testing to confirm accuracy and precision, the delivery of appropriate kinetic energy levels and projectile behaviour, (2) post-mortem assessment of ballistic injury in cadavers, (3) small-scale live animal pilot studies with predetermined threshold pass/fail levels, and (4) broad-scale use with reporting of the frequency of adverse animal welfare outcomes. We present this as a practical approach for maintaining and improving animal welfare standards when considering the use of ballistic technology for wildlife management.

Context. Line-transect sampling is considered to be a more efficient survey method than point-transect sampling to estimate population densities and abundance of many animal species.

Aims. In the present study, we tested whether this claim holds true when surveying arboreal fast-moving primate species occurring at low densities, and whether the potential difference in efficiency can be explained by the difference in the size of the survey area between the methods. We further examined the impact of survey effort for point-transect sampling.

Methods. We conducted line- and point-transect sampling for Geoffroy’s spider monkeys (Ateles geoffroyi) in the same locations and compared the numbers of detected individual monkeys and the probability of their occurrence per survey between the two methods. We further compared the data from point-transect sampling gathered within three different waiting periods.

Key results. We found a higher probability to detect monkeys and a higher number of monkeys during line-transect sampling than during point-transect sampling, but more spider monkeys were detected at point transects when controlling for the size of the survey area. More monkey detections were made during the first 10 min than during the second and third 10-min periods of point-transect surveys.

Conclusions. We showed that line-transect sampling is more efficient than point-transect sampling when surveying Geoffroy’s spider monkeys in a flat landscape of tropical forest with homogenous visibility. We discuss factors influencing survey results and recommend 20 min as the maximum waiting time at point transects when surveying arboreal mammals.

Implications. Our study has provided a quantitative approach to compare efficiency across survey methods for fast-moving arboreal animals that occur at low densities, and supports the use of point-transect sampling in sites where line-transect sampling is not feasible, such as in human-modified landscapes.

Context. Hawksbill sea turtles (Eretmochelys imbricata) are conservation-dependent species in many areas of the world. A key component to ensuring successful conservation initiatives for the species is understanding their distribution and habitat use, in particular, knowing the nesting sites, migration routes and foraging areas for each genetic stock, and how these might overlap with threats.

Aims. Investigate the post-nesting movements of hawksbill sea turtles nesting in the Torres Strait, including migration movements and foraging ground size and distribution.

Methods. Nine nesting hawksbill turtles of the north-eastern Australian genetic stock were satellite-tagged between the 2010 and 2019 nesting seasons for 182 ± 143 days (mean ± s.d.).

Key results. Three turtles continued to nest on adjacent islands before commencing their post-nesting migrations. From the nine tracked turtles, the following three migration movement strategies were identified: (1) direct migration between the nesting beach and foraging ground, (2) non-direct movements with a period of meandering, and (3) establishment of two foraging areas separated by direct movement pathways. Foraging grounds were distributed across the Torres Strait and north-eastern Australia and varied in size between 0.54 km² and 3.31 km² (95% UD). None of the turtles migrated outside of Australian waters.

Conclusions. The localisation of these movements and habitats within Australian waters provides a unique conservation opportunity, whereby protection efforts involve multiple life stages and potentially preserve turtles from multiple genetic stocks. The variety of inter-nesting, migration and home range strategies used by the tracked turtles in the present study highlight the broad scope of hawksbill movements.

Implications. Our findings are useful for the implementation of future marine conservation areas and shed light into the nesting, migratory and foraging behaviours of hawkbills from this genetic stock. An understanding of the movement tracks and habitats used by a genetic pool is essential for well grounded implementation of conservation areas and management regulations.

Context. The Gunnison sage-grouse (Centrocercus minimus) has experienced range-wide declines and has been listed as Threatened by the USA Fish and Wildlife Service to receive protections under the USA Endangered Species Act. A draft Recovery Plan was recently completed. No seasonal habitat models have been developed for the small isolated populations.

Aims. To develop a habitat suitability model that was collaboratively developed between modellers and conservation practitioners to predict the probability of use by Gunnison sage-grouse during the breeding and summer seasons in designated occupied critical habitat, and extrapolate to adjacent designated unoccupied critical habitat.

Methods. We captured, marked and tracked Gunnison sage-grouse in nine different studies spanning 25 years. We used a suite of biotic, abiotic and vegetation local-level and population-scale covariates in a use-available resource selection function to develop models that predict the probability of use by Gunnison sage-grouse.

Key results. We used 9140 Gunnison sage-grouse locations from 406 individual birds to develop nine resource selection models for occupied habitat and extrapolated model predictions to adjacent unoccupied critical habitat in five small isolated Gunnison sage-grouse populations. A majority of our models validated well.

Conclusions. We report the first two-season resource use-based habitat suitability models for five of six small isolated Gunnison sage-grouse populations. Because of the unique habitat use by Gunnison sage-grouse in each population, we recommend that resource managers strategically target management actions in individual populations and avoid ‘one-size-fits-all’ habitat management prescriptions.

Implications. Our models will assist managers in the identification of seasonal habitats within populations to target management actions for Gunnison sage-grouse recovery.

Context. The development of reliable and cost-efficient survey techniques is key to the monitoring of all wildlife. One group of species that presents particular challenges for monitoring is the arboreal mammals. Traditional techniques for detecting these species often yield low detection probabilities (detectability) and are time-consuming, suggesting the potential for novel methods to enhance our understanding of their distribution, abundance and population trajectories. One technique that has been shown to increase detectability in a range of terrestrial species is thermal imaging, although it has rarely been applied to arboreal species. The true conservation status of Lumholtz’s tree-kangaroo (Dendrolagus lumholtzi) is uncertain because of low detectability under typical survey techniques, and a more suitable method is required to enable effective monitoring of the species, making it an ideal candidate for the present study.

Aims. We aimed to compare the success and cost-effectiveness of surveys utilising thermal imaging with two traditional methods, namely, spotlighting and daytime surveys, so as to optimise monitoring of D. lumholtzi.

Methods. We conducted surveys at 10 sites in Queensland (Australia) where D. lumholtzi was known to occur, by using each method, and modelled both the detectability of D. lumholtzi and the cost-effectiveness of each technique.

Key results. Detectability of D. lumholtzi was significantly higher with the use of thermal imaging than it was with the other survey methods, and thermal detection is more cost-effective. In average survey conditions with a trained observer, the single-visit estimated detectability of D. lumholtzi was 0.28 [0.04, 0.79] in a transect through rainforest, by using thermal imaging. Using only spotlights, the detection probability was 0.03 [0, 0.28] under the same conditions.

Conclusions. These results show that incorporating thermal technology into monitoring surveys will greatly increase detection probability for D. lumholtzi, a cryptic arboreal mammal.

Implications. Our study highlighted the potential utility of thermal detection in monitoring difficult-to-detect species in complex habitats, including species that exist mainly in dense forest canopy.

Context. Mammal–seed interactions are important for structuring vegetation communities across a diverse range of ecosystems worldwide. In Australia, mammals are typically considered to be seed predators and to play insignificant roles in seed dispersal. However, very few studies have investigated endozoochorous seed dispersal in Australian species. The translocation of Australian mammals for the purposes of ecosystem restoration is increasing. Digging mammals (i.e. species that dig to obtain food or create shelter) are commonly the focus of these translocations because they are considered to be ecosystem engineers, but an understanding of their role in seed dispersal is lacking.

Aims. The aim of the present study was to expand the understanding of endozoochory in Australian digging mammals by determining whether seeds consumed by select species remain viable and able to germinate.

Methods. Scat samples were collected from five digging mammal species, known to consume seeds or fruit, across nine sites in Western and South Australia. The samples were searched for seeds, with the recovered seeds identified and tested for viability and germination capacity.

Key results. The abundance of intact seeds in scats was generally low, but 70% of the retrieved seeds appeared viable. Five species of seed germinated under laboratory conditions. These seeds were retrieved from bilby (Macrotis lagotis), boodie (Bettongia lesueur), golden bandicoot (Isoodon auratus) and quenda (I. fusciventer) scats.

Conclusions. Seeds consumed by Australian digging mammals can remain viable and germinate, indicating that digging mammals play a more important role in seed dispersal than previously considered.

Implications. Digging mammals have the potential to contribute to ecosystem restoration efforts through the dispersal of viable seeds, but there is also a risk that non-native species could be dispersed. These costs and benefits should be considered by practitioners when planning reintroductions of digging mammals.

Context. In central Queensland, Australia, the development of a coal-seam gas (CSG) industry is creating additional fragmentation of landscapes consisting of woodland and open forest that are already highly fragmented.

Aims. To assess the response to fragmentation of Strophurus taenicauda (golden-tailed gecko). The species is ‘near threatened’ in Queensland.

Methods. Occurrence and abundance were examined across three categories of patch size – small (≤10 ha), medium (10–100 ha) and large (≥100 ha) – across three geographic areas of the species’ range. Minimal impact (i.e. sighting only) active searches for geckos were conducted at night. A minimum of three replicate sites of each patch size category was surveyed in each of the three geographic areas. Eleven additional patches (each <4 ha and located in the southern geographic area) were surveyed to investigate how size and spatial isolation of small patches affected occurrence and abundance of S. taenicauda. At all sites a standardised set of 22 habitat variables was collected, and the presence of other species of arboreal gecko was recorded.

Key results. The species was located across patches of all sizes, including those as small as 1.11 ha. It was also located opportunistically in the matrix among patches and occurred in isolated trees within an urban area. The abundance of another commonly occurring arboreal gecko, Gehyra dubia (dubious dtella), was negatively correlated with S. taenicauda abundance in small patches. The most important habitat variable for S. taenicauda was average basal area of trees. As this increased, especially above 5.7 m² ha⁻¹, it was more likely to be present. When considering only the small patches, the main factors influencing presence and abundance of S. taenicauda were the average basal area of Callitris glaucophylla (white cypress) and grazing (negligible or absent).

Conclusions. Strophurus taenicauda is a species that is tolerant of disturbance and can persist in fragmented habitat, provided the fragments have adequate cover of white cypress.

Implications. The species appears to be resilient to the current level of CSG development within its geographic range.

Context. Invasive predators are a key threat to biodiversity worldwide. In Australia, feral cats are likely to be responsible for many extinctions of native mammal species in the south and centre of the continent.

Aims. Here we examine the effect of feral cats on native rodent populations in the second of two translocation experiments.

Methods. In a wild-to-wild translocation, we introduced pale field rats, Rattus tunneyi, whose populations are declining in the wild, into two pairs of enclosures where accessibility by feral cats was manipulated.

Key results. Individual rats translocated into enclosures accessible to cats were rapidly extirpated after cats were first detected visiting the enclosures. Rats in the enclosure not exposed to cats were 6.2 times more likely to survive than those exposed to cats. Two individual cats were responsible for the deaths of all but 1 of 18 cat-accessible rats. Rats in the site with denser ground cover persisted better than in the site with more open cover.

Conclusions. These results are consistent with our previous study of a different native rat species in the same experimental setup, and provide further evidence that, even at low densities, feral cats can drive local populations of small mammals to extinction.

Implications. Effective feral cat control may be necessary to enable recovery of small mammals.

Context. The koala (Phascolarctos cinereus) sometimes occurs as an overabundant folivore in south-eastern Australia, where high-density populations have caused defoliation of preferred food trees, threatening habitat. Kangaroo Island, South Australia and Budj Bim National Park, Victoria, are two regions where such eruptive population dynamics have arisen. One way of mitigating their damage is through management via fertility control.

Aims. This paper examines the outcomes of fertility control (surgical sterilisation and treatment with levonorgestrel implants) on breeding dynamics at the population level, using data obtained from two separate koala management programs conducted by State Government wildlife agencies, South Australia Department for Environment and Water and Parks Victoria.

Methods. The relationships between female body condition, reproductive status, fertility control, age and population density were examined using linear mixed effects models. Population density (koalas/ha) was estimated using annual census data and modelled in a Bayesian framework.

Key results. Body condition was a key influence on breeding success in female koalas, with sexual maturity being defined by both age and body condition, whereas the effect of reproductive experience was minimal. It is likely that reduced densities have led to decreased intraspecific competition for food resources and territory, leading to increased breeding success at one management site (BBNP) and by allowing females to begin breeding at a lower overall body condition. The reduction in densities to sustainable levels at both management sites, despite differing fertility-control methods, supports the use of the less invasive and more cost-effective levonorgestrel implants as the preferred fertility-control method.

Conclusions. In addition to contraceptive effects, broad-scale fertility control may have resulted in a compensatory higher breeding success in the untreated population, possibly in response to decreasing densities, increased resource availability or behavioural responses to population management.

Implications. Although compensatory breeding mechanisms can reduce the effectiveness of fertility control at the population level, ongoing fertility-control management can still be successful at reducing overabundant koala populations to sustainable levels with significant long-term commitment, provided that annual control targets are continuously met.