Context. Understanding the effects that learned responses to being captured have on subsequent recapture rates and associated abundance estimates is important for developing accurate descriptions of populations and communities. Although variation in the willingness of individual turtles to be trapped is commonly mentioned in the literature, few studies have experimentally tested learned trap avoidance (or fondness) in turtles.

Aims. To determine whether turtles learn to avoid traps, whether repositioning traps will lead to increased capture rates, whether this effect varies among species, and whether such relocations yield more accurate depictions of community structure.

Methods. We studied a community of turtles in a small lake in south-eastern Kansas that included populations of red-eared slider turtles (Trachemys scripta elegans) and common musk turtles (Sternotherus odoratus). We trapped the lake for 35 consecutive days by using two concurrently deployed groups of traps. One group remained stationary for the duration of the study, whereas traps comprising the other group were moved to new locations on Day 14 and returned to their original locations on Day 28, thus dividing the trapping season into three periods.

Key results. For both species, capture rates declined over time. However, traps in the moved group captured more T. s. elegans than did those in the stationary group during the second period and more S. odoratus during the third period. Traps in the moved group also had higher recapture rates in the second period. Population abundance estimates based on captures from the moved group, the stationary group, and the pool of all captures were similar for T. s. elegans, but for S. odoratus the stationary group of traps produced an abundance estimate much lower than those generated from the moved group and the pool of all captures.

Conclusions. Both species exhibited learned avoidance of trap locations, but relocating traps had distinct effects on different species, and the accuracy of the observed community structure was improved by relocating traps.

Implications. The movement patterns and catchability of individuals of different species within a community must be taken into consideration when developing trapping protocols. Even high-intensity trapping over a long period may not generate an accurate sample of the community if different species use the spatial environment in substantially different ways and learn to avoid trap locations.

Context. Accurate and precise monitoring practises are key for effective wildlife conservation management; providing reliable estimates of spatiotemporal changes in species abundance on which sound decision-making can be based. Advancements in drone and satellite technology are providing new standards for survey accuracy and precision and have great potential for enhancing population monitoring of numerous difficult to survey species. Flying-foxes (Pteropus spp.) are large bats that roost in groups of a few hundred to many thousands in the canopies of trees, where they are difficult to census accurately and precisely by human observers. Globally, 35 of the 64 flying-fox species are listed as threatened under the IUCN Red List of Threatened Species, and reliable monitoring methods are needed for the effective management of this ecologically important group.

Aims. Recently, we showed that drone-acquired thermal imagery can be used to count flying-foxes in their roost with high accuracy and precision. In the present study, we aimed to assess the accuracy and precision of whole colony counts derived from ground-based counting methods against reference counts derived from drone-acquired thermal imagery.

Methods. We evaluated the relationship between ground-based counts by two groups of human observers to highly accurate and precise counts derived from drone-acquired thermal orthomosaics for 25 counts conducted across seven flying-fox roosts throughout the Greater Sydney region, Australia.

Key results. We found that ground-based counts by human observers were positively correlated with those obtained from concurrent drone-acquired thermal imagery. However, drone-acquired estimates of colony size were 2.05 and 1.92 times higher than ground-based counts by the experimenter and Australian government counters respectively. When compared against drone-acquired reference counts, the precision (coefficient of variation) of ground-based counts was 26.3% when conducted by a single counter and 55.1% when conducted by multiple counters.

Conclusions. Our research indicates that ground-based counting methods underestimate true population sizes by substantial margins and have limited precision. Drone-based monitoring provides highly accurate and precise population estimates, and thus is expected to yield more reliable information on flying-fox abundance and allow for trends to be established over shorter timescales.

Implications. Using ground counting methods alone, population trends can only be established with significance after protracted periods of monitoring. Incorporating the use of thermal drones into current monitoring practises would enhance the capacity to detect population trends earlier and more accurately, so that conservation management can more effectively respond.

Context. Methods for estimating density of meso-carnivores in northern ecosystems are labour intensive and expensive to implement if mark–recapture and radio collaring are used. One alternative is to count tracks in the snow along transects as an index of density, but this method has been criticised as imprecise and lacking validation.

Aims. We aimed to examine the utility of track counts along snowmobile trails in the snow for measuring changes in populations of Canada lynx and coyotes in the boreal forest of north-western Canada.

Methods. We compared winter track counts of Canada lynx at three study sites and of coyotes at one site with concurrent estimates of density based on locations of radio-collared animals and estimates of numbers of uncollared animals from three 7–9-year studies in the Yukon and Northwest Territories, during a period of cyclical population fluctuations.

Key results. Snow track counts were positively correlated (r² = 0.83) with density of Canada lynx, estimated by live trapping and radio collaring in the three survey areas. Coyotes also showed a clear relationship (r² = 0.80) between known density and snow track counts, but track counts were strongly affected by season, with much higher counts in the early winter when snow was shallower. This indicates the need to control for season or snow depth when using track counts as indices of coyote abundance. We recommend sample sizes of at least 10 track counts per winter along a 25-km transect to maximise precision.

Conclusions. Snow track counts are a relatively simple, inexpensive method of concurrently tracking abundance of multiple species of meso-carnivores. These data indicate that track counts may be reliably used to monitor trends in numbers, but we suggest site-specific validation of the regressions reported here between tracks and animal abundance are required to translate these indices into estimates of density.

Implications. Track counts have the potential to be an affordable alternative to more intensive methods of monitoring trends in abundance of medium-sized mammals, for purposes such as management of harvest or to measure the success of programs to increase or reduce population abundance.

Context. Biodiversity monitoring programs provide information on the status and trends in wildlife populations. These trends are unknown for most mammals within African montane forests, which harbour many endemic and threatened species. Camera traps are useful for assessing mammal populations, because they allow for the estimation of species richness, occupancy, and activity patterns.

Aims. We sought to explore the richness and distribution of small- to large-sized mammals by using occupancy models while accounting for imperfect detection in Volcanoes and Mgahinga Gorilla National Parks, in Rwanda and Uganda.

Methods. We used camera-trap data collected from 2014 to 2017 by the Tropical Ecology Assessment and Monitoring (TEAM) network and multi-season occupancy models with multispecies data to assess the dynamics of species richness and distribution in the Virunga Massif and the influence of site covariates on species detection probability, occupancy, colonisation and extinction.

Key results. We identified 17 species from 7047 trap-days, with most of them showing an uneven distributional pattern throughout the park. We found that average species richness per site increased from five to seven species in 2017. Average local colonisation was estimated at 0.13 (s.e. 0.014), but the probability of local extinction was 0.17 (s.e. 0.028) and negatively influenced by distance from the park boundary. Detection probability was highest for medium-sized species. For species distribution, we found that black-fronted duiker, Cephalophus nigrifrons, and bushbuck, Tragelaphus scriptus, declined in distribution but remained widespread in our study area, while all other species showed an increase in distribution over the study period.

Conclusions. Our approach allowed us to draw inferences on rare species, such as African golden cat, Caracal aurata, by estimating detection probability on the basis of shared covariate information with more common, widespread species. As such, we were able to estimate all occupancy parameters across the terrestrial mammal community.

Implications. The results of this study on the distribution of terrestrial mammal species can be used by park management to inform optimal ranger patrolling efforts for mitigating threats in areas of high species presence. Additionally, the results can highlight locations of potential human–wildlife conflicts on the basis of species commonly found along the park boundary.

Context. Monitoring low-density, elusive predators such as grey wolves (Canis lupus) has often been undertaken via live-capture and radio-collaring. Recent advances in non-invasive methods suggest live-captures may not be necessary for adequate monitoring. Further, non-invasive methods are considered best practice when possible.

Aims. I evaluated whether a suite of non-invasive methods could replace aerial radiotelemetry to census resident pack wolves.

Methods. I employed aerial snow-tracking, ground snow-tracking, camera-trapping, non-invasive genetic surveys, and community-scientist reports during three winters (2019–2021) in north-eastern Minnesota, USA to census pack wolves in a 2060 km² area. I attempted to enumerate individual pack sizes as has been historically undertaken to compile the census. Traditional aerial radiotelemetry methods were also conducted for comparison.

Key results. Ground snow-tracking and camera-trapping provided the most similar information to radiotelemetry for determining pack counts and territory information, and, in some cases, documented higher pack counts than those obtained by aerial radiotelemetry. Radiotelemetry was the best method for determining pack territories, but was limited to radioed packs. A staggered application of both approaches resulted in increased precision and additional pack-level information without greatly increasing overall field effort. Non-invasive methods allowed trapping for radio-collaring to be reduced to every other year (a 50% reduction), but depending on trapping success, survival of animals, and radio-collar battery life, might even be reduced to every third year.

Conclusions. In this 3-year trial, non-invasive methods were not sufficient to completely replace radio-collaring. Nevertheless, non-invasive methods allowed for a 50% reduction in trapping, increased the annual wolf-count precision, and increased community involvement. Anticipated technological improvements in non-invasive methods should reduce some issues encountered – but others will likely persist, in part, because of the fundamental nature of non-invasive methods.

Implications. Less reliance on captures, enhanced pack information, and increased public involvement are all successful outcomes of this 3-year trial of non-invasive methods for monitoring wolf populations. Non-invasive methods continue to broaden and improve technologically, and information from trials such as this will help guide others as they increasingly implement non-invasive methods as partial or complete replacements for traditional capture-based methods.

Context. Exmouth Gulf is adjacent to the Ningaloo Marine Park, a UNESCO-listed area in Western Australia. The gulf remains largely unprotected, and is under increasing anthropogenic pressure from proposed industrial activities that pose threats to marine megafauna inhabiting the gulf. Threatened and near threatened species, such as the Australian humpback dolphin (Sousa sahulensis) and Indo-Pacific bottlenose dolphin (Tursiops aduncus), reside in the gulf; however, detailed information on their ecology and behaviour is lacking.

Aims. The aim was to (1) provide baseline data on the distribution, encounter rate, group size and behaviour of coastal dolphins over an area where current industrial developments are proposed, and (2) report on the occurrence of other marine megafauna within this area.

Methods. Boat-based photo-identification surveys were conducted on the western coastline of Exmouth Gulf along pre-determined line transects (150 km²) over austral autumn/winter 2021.

Key results. Across 809.35 km of surveyed waters (181 h), a total of 93 bottlenose dolphin, 15 humpback dolphin, and six interspecific dolphin groups were sighted. Bottlenose dolphin groups were encountered at a rate of 0.077/km, humpback dolphin groups at 0.015/km and interspecific dolphin groups at 0.005/km. Dolphins were predominantly recorded in shallow (mean 10 m) and warm (mean 21°C) waters, and were commonly travelling and foraging. In total, 199 individual bottlenose dolphins and 48 humpback dolphins were photo-identified (excluding calves). There were 30 bottlenose dolphin calves (including three newborns) and four humpback dolphin calves (including two newborns) identified. Other marine megafauna group sightings included humpback whales (Megaptera novaeangliae; n = 32), southern right whales (Eubalaena australis, n = 1), dugongs (Dugong dugon, n = 25), turtles (n = 54), sea snakes (n = 27), manta rays (Mobula alfredi, n = 13) and sharks (n = 2).

Conclusions. The presence of threatened marine species feeding, socialising, and resting highlights the importance of these waters for the identified species.

Implications. The information provided is applicable for the spatial management and conservation efforts of these species, and aids in informing environmental impact assessments of individual and cumulative pressures.

Context. Camera traps are available with infrared or white flash, with the former being more commonly used. However, white flash produces colour night-time photographs that can be critically useful for both species and individual identification. White flash was thought to cause more disturbance to wildlife than was infrared and this may lead to camera avoidance. Evaluating the extent of this response, and differences between the flash types, is useful to develop improved survey designs.

Aims. This research aimed to quantify the behavioural responses of Eld’s deer to white and infrared flash, to determine whether white-flash cameras were suitable for use in population surveys of this species.

Methods. A behavioural ethogram was used to quantify the responses of the deer to the two flash types, as well as the responses of different sex-age classes and group sizes when encountering a camera trap. Additionally, the detection rate for white flash and infrared flash cameras was compared through time, to determine any pattern of avoidance.

Key results. While deer were more likely to observe and be startled by white flash than infrared, this did not adversely affect the detection of the deer, with no significant change in the detection rate between the two different flash types over time. Group size was found not to influence behavioural response when encountering camera traps, whereas different age–sex classes of deer showed very few differences in response to camera traps.

Conclusions. White flash cameras were found to be suitable for Eld’s deer population surveys and were beneficial in providing colour night-time photos that allow for spotted female deer to be individually identified.

Implications. Practitioners should not be concerned about the influence of white flash when using camera traps to monitor populations of Eld’s deer, and using white flash is recommended when individual identification is required.