Context. Aerial surveys provide valuable information about the population status and distribution of many native and pest vertebrate species. They are vital for evidence-based monitoring, budget planning and setting management targets. Despite aircraft running costs, they remain one of the most cost-effective ways to capture distribution and abundance data over a broad area. In Australia, annual surveys of large macropods are undertaken in several states to inform management, and in some jurisdictions, to help set commercial kangaroo harvest quotas. Improvements in the cost efficiencies of these surveys are continually sought. Aerial thermal imaging techniques are increasingly being tested for wildlife surveys, but to date no studies have directly compared population data derived from thermal imaging with data collected by human observers during the same flight.

Aims. During an aerial survey of western grey kangaroos (Macropus fuliginosus), eastern grey kangaroos (M. giganteus) and red kangaroos (Osphranter rufus) across the state of Victoria, Australia, the objective was to conduct a direct comparison of the effectiveness of thermal camera technology and human observers for estimating kangaroo populations from aerial surveys.

Methods. A thermal camera was mounted alongside an aerial observer on one side of the aircraft for a total of 1360 km of transect lines. All thermal footage was reviewed manually. Population density estimates and distance sampling models were compared with human observer counts.

Key results. Overall, the kangaroo density estimates obtained from the thermal camera data were around 30% higher than estimates derived from aerial observer counts. This difference was greater in wooded habitats. Conversely, human-derived counts were greater in open habitats, possibly due to interference from sunlight and flushing. It was not possible to distinguish between species of macropod in the thermal imagery.

Conclusions. Thermal survey techniques require refining, but the results of the present study suggest that with careful selection of time of day for surveys, more accurate population estimates may be possible than with conventional aerial surveys.

Implications. Conventional aerial surveys may be underestimating animal populations in some habitats. Further studies that directly compare the performance of aerial observers and thermal imaging are required across a range of species and habitats.

Context. Ecotones are recognised globally as areas of high biodiversity, yet relatively little is known about how fauna use different types of ecotone. Tropical rainforest–grassland ecotones are shaped through particular fire regimes, creating both gradual and abrupt ecotones. Insectivorous bats contribute considerably to mammalian diversity, and their capacity for flight allows them to use ecotones in a three-dimensional way, making them an informative faunal group for evaluating ecotone use.

Aims. To critically evaluate how insectivorous bats use gradual and abrupt ecotones between rainforest and grassland habitats.

Methods. Bat detectors were placed every 50 m, along 200-m transects, through five gradual and five abrupt rainforest–grassland ecotones. The activity of all insectivorous bats, as well as open, edge–open and closed foraging guilds (defined by echolocation call type), was compared among grassland and rainforest habitats, gradual and abrupt ecotones and positions across the ecotones.

Key results. Mean total bat activity, mean open and edge–open foraging guild activity were significantly higher in grassland positions, followed by the edge, and were lowest in the rainforest. Closed foraging guild bats showed no preference for either habitats, but had significantly higher activity in gradual compared with abrupt ecotones. Mean activity of edge–open foraging guild bats was affected strongly by the interaction between ecotone type and position along the ecotone. Gradual ecotones had a more even proportion of all three bat foraging guilds along the ecotone compared with abrupt ecotones. Most of these findings were likely driven by the structural complexity of gradual ecotones that fulfilled microhabitat requirements for all three foraging guilds, but may also have been influenced by insect prey abundance.

Conclusions. The present study demonstrated the importance of grassland patches in a tropical, rainforest landscape, and of gradual rainforest–grassland ecotones for insectivorous bats. Gradual ecotones promote complex habitat mosaics to allow closed foraging guild species to take advantage of food resources provided by grasslands, and provide all bats proximity to potential roosting and foraging sites.

Implications. The data clearly suggest that a suitable fire regime should be used to maintain current grassland patches within a rainforest landscape, and to promote gradual ecotones for use by insectivorous bats.

Context.Pseudogymnoascus destructans is the fungus responsible for white-nose syndrome (WNS), which has killed millions of hibernating bats in North America, but also occurs in bats in Europe and China without causing large-scale population effects. This is likely to be due to differences in species susceptibility and behaviour, and environmental factors, such as temperature and humidity. Pseudogymnoascus destructans is currently believed to be absent from Australia.

Aims. To ascertain the level of risk that white-nose syndrome poses for Australian bats.

Methods. This risk analysis examines the likelihood that P. destructans enters Australia, the likelihood of the fungus coming in contact with native bats on successful entry, and the potential consequences should this occur.

Key results. This risk assessment concluded that it is very likely to almost certain that P. destructans will enter Australia, and it is likely that bats will be exposed to the fungus over the next 10 years. Eight cave-dwelling bat species from southern Australia are the ones most likely to be affected.

Conclusions. The risk was assessed as medium for the critically endangered southern bent-winged bat (Miniopterus orianae bassanii), because any increase in mortality could affect its long-term survival. The risk to other species was deemed to range from low to very low, owing to their wider distribution, which extends beyond the P. destructans risk zone.

Implications. Although Australia’s milder climate may preclude the large mortality events seen in North America, the fungus could still significantly affect Australian bat populations, particularly bent-winged bats. Active surveillance is required to confirm Australia’s continuing WNS-free status, and to detect the presence of P. destructans should it enter the country. Although White-nose Syndrome Response Guidelines have been developed by Wildlife Health Australia to assist response agencies in the event of an incursion of WNS into bats in Australia, these guidelines would be strengthened by further research to characterise Australian cave temperatures and hibernating bat biology, such as length of torpor bouts and movement over winter. Risk-mitigation strategies should focus on education programs that target cavers, show-cave managers and tourists, particularly those who have visited regions where WNS is known to occur.

Context. Urban protected areas (PAs) are the habitat of several Neotropical medium-sized wild mammal (MSWM) species. However, this richness is seriously threatened by the growing populations of free-ranging dogs and cats in these areas.

Aims. The aim of the present study was to evaluate the effect of free-ranging dogs and cats on the assemblage structure of MSWM in PAs of Xalapa city, Veracruz, Mexico.

Methods. Camera traps were used to assess the effect of abundance and activity of dogs and cats on richness, abundance, dominance and activity of MSWM across two urban and three peri-urban PAs. The effect of plant diversity, vegetation structure and PA on mammal richness, activity and abundance were also evaluated.

Key results. The dominance of MSWM was higher in peri-urban areas than urban areas, and the activity of dogs and cats from peri-urban and urban PAs was similar with wildest MSWM. Only inside urban areas did the size of the area and the dogs’ activity have a negative effect on the richness, activity and abundance of MSWM. Moreover, the activity and abundance of cats also had a negative effect on the activity of MSWM in urban PAs. The presence of dogs affected the latency of appearance of MSWM.

Conclusions. The presence of free-ranging dogs and cats in urban PAs affects MSWM assemblages and their appearance latency.

Implications. The potential harm of free-ranging dogs and cats on the community of MSWM in urban areas is clear, as is the need for increased scientific research to aid in the control of these exotic species in urban landscapes.

Context. Physiological stress has the potential to influence animal population persistence. The endangered Asian elephant (Elephas maximus) is involved in intense conflict with humans in many parts of its range, which likely leads to stress for individuals and groups, with consequences for population survival. Thus, it is important to understand how the elephants’ stress levels are influenced by socio-ecological factors when not directly exposed to human-induced threats, and to use this understanding to improve conservation and management strategies.

Aims. The present study was designed to provide baseline information on the link between socio-ecological factors and stress levels of undisturbed populations of elephants. The main aim was to determine the influence of a number of factors – herd size, season, number of calves and adult females present in a herd and their lactational status and body condition – on the adrenocortical activity of free-ranging adult female Asian elephants living in protected forests (without any direct exposure to human-induced threats), by measuring their faecal glucocorticoid metabolite (fGCM) levels.

Methods. A total of 145 fresh faecal samples were collected from 123 identified adult female elephants inhabiting Bandipur and Nagarahole National Parks of southern India, between the years 2013 and 2015. fGCM levels were measured by employing a group-specific standardised 11-oxoetiocholanolone enzyme immunoassay (EIA). A generalised linear mixed-effects model (GLMM) was used to assess the influence of socio-ecological factors on fGCM levels of adult female elephants.

Key results. When fGCM levels were analysed with a GLMM, the following patterns were observed: fGCM levels were negatively correlated with the number of adult females (herd size) and positively correlated with the number of calves in a herd and active lactational status of an adult female. fGCM levels of adult female elephants were higher during the dry season (February to May) than wet season (August to December) and negatively correlated with body condition scores.

Conclusions. Adrenocortical activity of female elephants is significantly influenced by the number of calves and adult females present in the herd, seasonality and lactational status.

Implications. It is important to consider the influence of multiple ecological and social correlates when assessing and interpreting the adrenocortical activity of Asian elephants. Our findings highlight the importance of maintaining the social structure of elephants in the wild to avoid detrimental effects on their physiological health. Insights from such assessments could be used to evaluate the stress in elephants that are involved in direct conflicts with humans to take appropriate management decisions for mitigating conflicts.

Context. Trapping design influences information collected about wildlife populations and biodiversity. Trapping is also resource-intensive and has animal welfare implications.

Aims. The scientific, financial and ethical performances of three trap designs were compared for estimating diversity and sampling small vertebrates.

Methods. Small vertebrates were trapped over 16 trapping sessions, from April 2009 to May 2011, with aluminium box-style (Elliott) traps and two pitfall trap designs (shallow–wide and deep–narrow), in an arid environment.

Key results. Shallow pitfalls recorded highest overall species richness (S = 22) and diversity (^qD = 10.622), reptile diversity (^qD = 8.112) and reptile capture rates (13.600 individuals per 100 trap nights). Shallow and deep pitfalls sampled ∼79.0% and 85.0% (respectively) more small mammals than did Elliott traps. Deep pitfalls sampled the greatest diversity (^qD = 6.017) and number (29.700 individuals per 100 trap nights) of small mammals, and captured the greatest number of small mammal species (0.003) and individuals (0.106) per dollar. Shallow pitfalls were the most cost-efficient trap type for sampling reptile species (0.003) and individuals (0.044) per dollar. Between-session recapture rates were greatest in Elliott traps, indicating an increased likelihood of biased capture rates for certain small mammal species over time. Elliott traps were the least efficient traps on most scientific and cost measures, and recorded the greatest overall recapture rates, particularly for Sminthopsis crassicaudata and S. macroura. Body size of one species only, the nationally threatened Pseudomys australis, influenced its capture rate, with larger individuals more likely to be caught in deep pitfalls. Mortality was highest in pitfalls and mostly related to interactions between animals caught in the same trap.

Key conclusions. Shallow pitfalls are suitable for studies focused on estimating species richness, and reptile diversity and abundance. Deep pitfalls are cost-effective for sampling small mammals. Ethical issues associated with pitfalls could be managed by checking traps more often at night, and/or including materials that provide increased protection from predators caught in the same trap, particularly during periods of high abundance.

Implications. Trap design profoundly influences cost-effectiveness and welfare outcomes of wildlife research. We provide a tool to assist cost-benefit related decisions.

Context. A series of unprovoked shark attacks on New South Wales (Australia) beaches between 2013 and 2015 triggered an investigation of new and emerging technologies for protecting bathers. Traditionally, bather protection has included several methods for shark capture, detection and/or deterrence but has often relied on environmentally damaging techniques. Heightened environmental awareness, including the important role of sharks in the marine ecosystem, demands new techniques for protection from shark attack. Recent advances in drone-related technologies have enabled the possibility of real-time shark detection and alerting.

Aim. To determine the reliability of drones to detect shark analogues in the water across a range of environmental conditions experienced on New South Wales beaches.

Methods. A standard multirotor drone (DJI Inspire 1) was used to detect shark analogues as a proxy during flights at 0900, 1200 and 1500 hours over a 3-week period. The 27 flights encompassed a range of environmental conditions, including wind speed (2–30.0 km h⁻¹), turbidity (0.4–6.4 m), cloud cover (0–100%), glare (0–100%), seas (0.4–1.4 m), swells (1.4–2.5 m) and sea state (Beaufort Scale 1–5 Bf).

Key results. Detection rates of the shark analogues over the 27 flights were significantly higher for the independent observer conducting post-flight video analysis (50%) than for the drone pilot (38%) (Wald P = 0.04). Water depth and turbidity significantly impaired detection of analogues (Wald P = 0.04). Specifically, at a set depth of 2 m below the water surface, very few analogues were seen by the observer or pilot when water turbidity reduced visibility to less than 1.5 m. Similarly, when water visibility was greater than 1.5 m, the detection rate was negatively related to water depth.

Conclusions. The present study demonstrates that drones can fly under most environmental conditions and would be a cost-effective bather protection tool for a range of user groups.

Implications. The most effective use of drones would occur during light winds and in shallow clear water. Although poor water visibility may restrict detection, sharks spend large amounts of time near the surface, therefore providing a practical tool for detection in most conditions.

Context. Federally protected wild horses on public lands are undergoing population growth that overwhelms the historical management strategy of removal and adoption. Porcine zona pellucida (PZP) has been used as an injectable immunocontraceptive vaccine to induce reversible infertility in free-roaming horses. PZP vaccination during February and March, which is the optimal time for administering current vaccines, is not possible for the herd on Jarita Mesa Wild Horse Territory (JM WHT), New Mexico, due to severe weather, terrain and subject wariness.

Aims. The first goal was to assess bait trapping and remote darting as a minimally disruptive alternative to helicopter gathers for treatment. The second goal was to quantify the efficacy over 2 years following spring treatment with a single injection of PZP-22 (a combination of PZP-adjuvant emulsion and controlled-release pellets) by remote dart delivery.

Methods. Bait trapping and dart delivery of PZP-22 was carried out on JM WHT from 4 April to 16 June 2012. The herd was observed in the summers of 2011, 2013 and 2014 to determine the foaling status of the study mares. Outcome (foal or no foal) as a function of treatment was analysed using Fisher’s exact test.

Key results. There were 157 individuals, including 66 females >1 year old, documented in 2011. In 2012, 26 females (including three yearlings) identified by colour and markings were bait trapped and darted with PZP-22. The proportion of treated females foaling was lower than that of untreated females in 2013 and 2014, but the difference was only significant in 2013. Of the treated mares observed in 2013, the two that foaled were the last two treated in 2012. Untreated mares >4 years old were significantly more likely to foal than younger mares.

Conclusions. Bait trapping at JM WHT permitted successful delivery of PZP-22 in a previously inaccessible herd. Dart administration of PZP-22 in April–June induced at least 1 year of measurable infertility.

Implications. This is the first demonstration of the efficacy of an initial treatment of PZP-22 delivered by dart instead of hand injection. Considerations for PZP-22 treatment include seasonal timing of treatments and age of treated mares. Treatments need to take place early enough to allow antibody titers to build to contraceptive levels before the breeding season.

Context. Human disturbance threatens many bird species worldwide. Flight-initiation distances (FIDs) offer a scientific basis for separation distances between fauna and agents of disturbance, such as people. However, most available FIDs are from single-species groups. Multi-species flocks have received scant attention with regard to their FIDs; yet, they are extremely common in nature.

Aim. To examine suitable separation distances for mixed-species shorebird flocks by comparing single-species FIDs with those of the same species in mixed-species flocks.

Method. We examined FIDs in mixed- and single-species flocks of four shorebirds (double-banded plover, Charadrius bicinctus, red-capped plover, Charadrius ruficapillus, red-necked stint, Calidris ruficollis, and curlew sandpiper, Calidris ferruginea). FIDs were collected in comparable habitat and sites with similar (i.e. highly restricted) regimes of human occurrence.

Results. FIDs of single-species flocks of these species differed in their FID to an approaching walker. Different species permutations in mixed-species flocks resulted in different FIDs. FIDs of mixed-species flocks were lower than or the same as the FIDs of single-species groups of constituent species.

Conclusions and implications. In our study system, separation distances (e.g. buffers; zones that exclude humans to reduce shorebird disturbance) based on FIDs of single species also would be efficacious for mixed-species flocks containing those species.