Context. Vehicle-strike has been identified as a key threatening process for koala (Phascolarctos cinereus) survival and persistence in Australia. Roads and traffic act as barriers to koala movement and can impact dispersal and metapopulation dynamics. Given the high cost of wildlife mitigation structures such as purpose-built fauna-specific underpasses or overpasses (eco-passages), road construction and management agencies are constantly seeking cost-effective strategies that facilitate safe passage for fauna across roads. Here we report on an array of detection methods trialled to verify use of retrofitted road infrastructure (existing water culverts or bridge underpasses) by individual koalas in fragmented urban landscapes in south-east Queensland.

Aims. The study examined whether the retrofitting of existing road structures at six sites facilitated safe passage for koalas across roads. Our primary objective was to record utilisation of retrofitted infrastructure at the level of the individual.

Methods. We used a combination of existing monitoring methods such as GPS/VHF collars, camera traps, sand plots, and RFID tags, along with a newly developed animal-borne wireless identification (WID) tag and datalogging system, specifically designed for this project, to realise the study aims.

Key results. We were able to verify 130 crossings by koalas involving a retrofitted structure or a road surface over a 30-month period by using correlated data from complementary methods. We noted that crossings were generally uncommon and mostly undertaken by only a subset of our tagged individuals at each site (21% overall).

Conclusions. An important element of this study was that crossing events could be accurately determined at the level of the individual. This allowed for detailed assessment of eco-passage usage, rather than the more usual approach of simply recording species’ presence.

Implications. This study underscores the value of identifying the constraints of each individual monitoring method in relation to site conditions. It also highlights the benefits of contingency planning to limit data loss (i.e. using more than one method to collect data). We suggest an approach that uses complementary monitoring methods has significant advantages for researchers, particularly with reference to improving understanding of whether eco-passages are meeting their prescribed conservation goals.

Context . Little is known about the consequences of sexual segregation (differential use of resources by the sexes outside of the mating season) for the conservation of large mammals. Roadways (i.e. the strip of land over which a road or route passes) are ubiquitous around the world, and are a major cause of wildlife mortality, as well as habitat loss and fragmentation. Many populations of bighorn sheep (Ovis canadensis) occur at low densities and in a metapopulation structure. Roadways could affect movements of males and females differentially, an outcome that has not been considered previously.

Aims . We investigated the propensity of the sexes to cross a paved two-lane road and a single-lane, maintained dirt route and predicted that adult males, because of their life-history characteristics, would cross those roadways more often than females.

Methods . We investigated movements of male and female bighorn sheep from 1986 to 1990. We used a fixed-wing aircraft with an H-antenna on each wing strut to locate individuals each week from October 1986 to December 1990. We estimated the degree of overlap among 50% core areas of use by males and females with the utilisation distribution overlap index (UDOI).

Key results . We relocated male and female bighorn sheep on 948 occasions during sexual aggregation and on 1951 occasions during sexual segregation. More males than females were likely to cross both types of roadways during segregation, and the dirt route during aggregation. Propensity of males and females to cross roadways was strongly influenced by time of year (i.e. whether the period of sexual aggregation or sexual segregation). The lowest overlap in 50% core areas was between females and males during periods of segregation (UDOI = 0.1447).

Conclusions . More males than females crossed Kelbaker Road and the unnamed dirt route during segregation, as well as the unnamed route during aggregation. Both of those features could affect males more than females, and could result in reductions in the use of habitat or increased mortality of bighorn sheep from vehicle collisions as a result of spatial segregation of the sexes.

Implications . During environmental review, biologists should consider sexual segregation when assessing potential anthropogenic effects on movements of bighorn sheep. Biologists also should consider sexual segregation and how roadways, even lightly traveled routes, affect movements of male and female ungulates differently before manipulating habitat, translocating animals, or constructing or modifying roadways.

Context. Pocket gophers (Geomyidae) cause extensive damage to many crops throughout western North America. A variety of methods are available to manage these populations, but data are often lacking on their efficacy and especially their cost effectiveness. Additionally, little peer-reviewed data are available that compare multiple methods simultaneously.

Aims. We tested aluminum phosphide and pressurised exhaust using the Pressurised Exhaust Rodent Controller (PERC) as burrow fumigants, and compared them to trapping to determine which approach was most efficacious and cost effective.

Methods. We assessed the efficacy of aluminum phosphide, the PERC machine, and trapping through the use of the open-hole monitoring method after single and multiple treatments over multiple years. We determined material and labour costs for each treatment type and amortised this cost over 1250 days of application to determine which treatment type was most cost effective.

Key results. Aluminum phosphide had the shortest time for application, but we were able to make far more applications per day using the PERC machine, given our ability to treat multiple burrow systems at once with this machine. Trapping and aluminum phosphide were more efficacious than was the PERC machine. When costs were amortised over time, trapping was the most cost-effective approach even with longer application times, given high efficacy. Multiple treatment applications were needed to maximise the efficacy of management programs.

Conclusions. For small-scale management efforts, aluminum phosphide was a cost-effective and efficacious option. For a greater number of treatments, trapping was the most successful and cost effective. However, a modest increase in efficacy could make the PERC machine a preferred tool as well. We also stress that regardless of the management approach, multiple treatment applications will generally be needed to manage pocket gopher populations.

Implications. The present study provides growers with information needed to determine efficient and cost-effective methods for managing pocket gophers. This information can be used to craft an integrated pest-management approach to manage damaging pocket gopher populations.

Context . Source populations of many large carnivores such as tigers (Panthera tigris) are confined within small wildlife refuges in human-dominated landscapes. Appropriate management of these populations may warrant understanding fine-scale use of habitat.

Aims . The aim of the present study is to understand the fine spatial-scale habitat associations of tigers in Chitwan National Park, Nepal.

Methods . We conducted camera-trap surveys across the park and applied an occupancy modelling approach to assess the probability of tiger detection and occurrence as a function of fine-scale habitat covariates.

Results . Tiger detection probability as a function of fine-scale habitat covariates was ≤0.20 compared with that of a constant detection model. Detectability patterns were best explained by models incorporating the effect of prey, slope and landcover type. Similarly, the best occupancy model incorporating the detection probability included prey, landcover type, water and slope. Tiger occurrence patterns were positively associated with prey availability and certain landcover types such as grasslands. Contrary to expectation, occurrence probability decreased further from human settlements. However, as expected, the occurrence of tigers was higher in proximity to water sources.

Conclusions . Both tiger detection and occurrence are influenced by fine-scale habitat factors, including prey availability. In small protected areas, individuals may persist at high population densities by intensively focusing their activity on small portions of their home ranges.

Implications . Our study provided insight into the fine spatial-scale occurrence probability of tigers, and thereby aids in developing appropriate habitat management strategies at the protected-area level. Our approach is broadly applicable to the robust assessment of fine-scale wildlife–habitat associations of many wide-ranging species that are ecologically ‘confined’ in smaller protected areas.

Context. Demographic parameters in wildlife populations are typically estimated by monitoring a limited number of individuals in observable sites and assuming that these are representative of the whole population. If individuals permanently disperse to unobservable breeding sites, recruitment and immature survival are expected to be negatively biased and breeding-site fidelity cannot be investigated.

Aims. To develop a method to obtain unbiased estimated of survival, recruitment and breeding dispersal when individuals can move to, or recruit in, unobservable sites.

Methods. We used the flexibility of multi-event capture–recapture models to estimate dispersal and recruitment to unobservable sites, merging observations made at two sites within the same breeding locations. We illustrated the model with data on little penguin (Eudyptula minor) breeding in artificial as well as in natural nests. Natural nests are unknown or inaccessible and birds in these sites remain unobservable. Encounters at beaches surrounding the colony suggested that marked animals can permanently move to unobservable nests. We built the multi-event model considering two possible states of the individuals (alive breeding in a nest box and alive in a natural nest) and three types of observations (encountered at a nest only, encountered at the beach only and encountered at both places). This model ensured that the breeding dispersal to unobservable places became estimable.

Key results. Results indicate that the estimated survival was 8% higher than when recaptures at artificial nests were analysed alone. Also, fidelity to artificial nests was 12% lower than to natural nests. This might reflect the greater availability of natural sites or, alternatively, a heterogeneity between these two types of nest.

Conclusions. We obtained an estimate of local survival of little penguins breeding at Penguin Island that incorporates the permanent migration to unobservable sites and found an asymmetric dispersion towards natural nests.

Implication. Our conclusions suggest a need for more careful treatment of data derived from artificial sites alone, as demographic parameters might be underestimated if animals prefer natural breeding sites or if they are in greater proportion compared with artificial ones. The analytical approach presented can be applied to many biological systems, when animals might move into inaccessible or unobservable breeding sites.

Context . Human activities can affect habitat selection by ungulates during parturition. Minimising human–wildlife conflicts during the birthing period can be critical in national and state parks that receive high numbers of human visitors. American bison (Bison bison) are an iconic species in North America, and many conservation herds of bison occupy national and state parks and wildlife refuges.

Aims . We investigated timing of births and birth-site selection of bison on Antelope Island State Park, Utah, at multiple spatial scales to determine the relative influence of surrounding vegetation, topography and distance to anthropogenic features (i.e. trails, roads or structures) on selection of birthing habitat.

Methods . We used vaginal implant transmitters to determine timing of births and to identify birth sites of bison. We used logistic regression within a model-selection framework to differentiate between birth sites and random locations, based on potential explanatory variables. We then used model-averaged coefficients to produce and project a GIS model of birthing habitat onto Antelope Island.

Key results . During 2010 and 2011, we quantified variables surrounding 35 birth sites and 101 random sites. Variables in top models of birth-site selection for bison included landscape curvature and elevation, averaged at a 500-m radius around birth sites, as well as distance to nearest trails, roads or structures. Five-fold cross validation (rho = 0.89; P < 0.05) indicated that these variables successfully predicted birth sites of bison in our study area; 80% of 41 births occurred in April (range = March 22 to May 20).

Conclusions . Bison selected areas for birthing with concave topography and increased elevation that were away from trails, roads or structures.

Implications . Our GIS model of birthing habitat, and data concerning timing of births, provide a map of high-probability birthing areas and a time of year at which human access could be limited to reduce disturbance from recreational activity. This approach could aid managers in minimising conflict between recreationists and parturient bison in other national and state parks and wildlife refuges.

Context. Helicopter darting (chemical immobilisation) is a very useful technique for large wild herbivores, such as feral horses (Equus caballus). There is currently no reliable framework to report on the animal welfare impacts of helicopter darting methods.

Aim. The aim of this study was to develop an animal welfare assessment framework for helicopter darting methods, using quantifiable parameters, and to test it with a case study using a newly developed feral horse capture technique.

Methods. Quantifiable animal welfare parameters were recorded for 11 feral horses captured using a traditional helicopter darting method in north-western Australia in October 2014. Welfare parameters chosen focused on quantifying the duration of procedures and the frequency of adverse events. They included chase time (CT; min) before darting, induction time (IT; min) between darting and recumbency, recumbency time (RT; min), total time (TT; CT IT RT; min), repeat-darting rate (animals requiring >1 dart; %), target zone accuracy rate (darts striking the intended anatomical area; %) and mortality rate (at time of capture and 14 days post-capture; %).

Results. Median CT was 2 min, median IT was 19 min, median RT was 16 min and median TT was 38 min. Repeat-darting rate was 45%, target zone accuracy rate was 53% and mortality rates (time of capture and 14 days post-capture) were zero.

Conclusions. Animal welfare parameters can be quantified for helicopter darting through estimation of the duration of procedures and the frequency of adverse events. Use of this framework will allow the identification of parameters requiring refinement for newly developed helicopter darting techniques.

Implications. Animal welfare parameters are particularly important for helicopter-based darting methods. Pilot studies, using quantified parameters, should be performed for newly developed capture techniques before they are approved for large-scale programs.

Context . Restoration of disturbed vegetation communities commonly involves altering vegetation composition and structure, attributes that can influence the suitability of habitat for fauna. Feedbacks may occur whereby changes to the vegetation affect mammalian herbivores, and unintended changes may prevent managers from achieving conservation goals.

Aims . To understand how vegetation management affects habitat use by five mammalian herbivores, namely eastern grey kangaroo (Macropus giganteus), swamp wallaby (Wallabia bicolor), common wombat (Vombatus ursinus), European rabbit (Oryctolagus cuniculus) and hog deer (Axis porcinus).

Methods . A management experiment (mechanical slashing of the encroaching shrub Leptospermum laevigatum) at Wilsons Promontory National Park, Australia, created slashed swales in addition to untreated dune and scrub woodland. In each vegetation stratum, we estimated the cover of L. laevigatum and quantified herbivore abundance by counting the standing crop of faecal pellets.

Key results . Relative to untreated vegetation, mechanical slashing of L. laevigatum substantially reduced cover of this species above 200 cm, but increased its cover below 30 cm. On the basis of faecal-pellet counts, multispecies use of managed and unmanaged parts of the landscape differed substantially, with the differences principally driven by higher abundance of European rabbits and eastern grey kangaroos at slashed sites.

Conclusions . The responses of three grazing species (kangaroo, rabbits and wombats) to vegetation management were predicted well by prior knowledge of diet and habitat preferences. This was not the case for the browser (swamp wallaby), nor for the grazer that consumes substantial amounts of browse in the study area (hog deer), and additional knowledge of the processes underlying their responses to vegetation change is required.

Implications . Our findings highlighted that vegetation management can influence herbivore abundances in the managed system. An improved understanding of these associations will allow vegetation management plans to incorporate herbivore responses.