Evaluating the metapopulation consequences of ecological traps

Ecological traps occur when environmental changes cause maladaptive habitat selection. Despite their relevance to metapopulations, ecological traps have been studied predominantly at local scales. How these local impacts scale up to affect the dynamics of spatially structured metapopulations in heterogeneous landscapes remains unexplored. We propose that assessing the metapopulation consequences of traps depends on a variety of factors that can be grouped into four categories: the probability of encounter, the likelihood of selection, the fitness costs of selection and species-specific vulnerability to these costs. We evaluate six hypotheses using a network-based metapopulation model to explore the relative importance of factors across these categories within a spatial context. Our model suggests (i) traps are most severe when they represent a large proportion of habitats, severely reduce fitness and are highly attractive, and (ii) species with high intrinsic fitness will be most susceptible. We provide the first evidence that (iii) traps may be beneficial for metapopulations in rare instances, and (iv) preferences for natal-like habitats can magnify the effects of traps. Our study provides important insight into the effects of traps at landscape scales, and highlights the need to explicitly consider spatial context to better understand and manage traps within metapopulations.     

The influence of potential stressors on oviposition site selection and subsequent growth,survival and emergence of the non‐biting midge (Chironomus tepperi)

Theory predicts that animals should prefer habitats where their fitness is maximized but some mistakenly select habitats where their fitness is compromised, that is, ecological traps. Understanding why this happens requires knowledge of the habitat selection cues animals use, the habitats they prefer and why, and the fitness costs of habitat selection decisions. We conducted experiments with a freshwater insect, the non‐biting midge Chironomus tepperi to ask: (a) whether females respond to potential oviposition cues, (b) to explore whether oviposition is adaptive in relation to metal pollution and conductivity, and (c) whether individuals raised in poor quality sites are more likely to breed in similarly poor locations. We found the following: (a) females responded to some cues, especially conductivity and conspecifics, (b) females preferred sites with higher concentrations of bioavailable metals but suffered no consequences to egg/larval survival, (c) females showed some avoidance of high conductivities, but they still laid eggs resulting in reduced egg hatching, larval survival, and adult emergence, and (d) preferences were independent of natal environment. Our results show that C. tepperi is susceptible to ecological traps, depending on life stage and the relative differences in conductivities among potential oviposition sites. Our results highlight that (a) the fitness outcomes of habitat selection need to be assessed across the life cycle and (b) the relative differences in preference/suitability of habitats need to be considered in ecological trap research. This information can help determine why habitat preferences and their fitness consequences differ among species, which is critical for determining which species are susceptible to ecological traps.     

Optimizing spatial positioning of traps in the context of integrated pest management

Agricultural research often relies on methods and approaches to represent and explain complex agro-ecosystems processes. In the context of biological control, auto dissemination strategies have been widely embraced for the management of various pests. One such strategy is using traps that attract arthropods into the hub of fungal based entomopathogens. The trapped pests are infected with the entomopathogen, which can then disseminate it among its conspecifics after being released. Despite the potential of the technique, its adoption especially by smallholder farmers has been limited, most likely due to the lack of an efficient trap positioning strategy. In this study, we propose an approach to improve the field application of fungal-based bio-pesticides (entomopathogenic fungi or EPF) by optimizing the spatial distribution of traps. The optimal field distribution of traps can be determined based on the following steps: (i) a field experiment to assess the dispersal ability of the pest infected by an entomopathogenic fungi (EPF) and (ii) the model-based estimation of the optimum traps density and distribution per unit of space (ha, km²). Based on experimental data we applied nonlinear regression and spatial optimization processes to calculate the radius covered by one trap and to estimate the optimum number and spatial positioning of the traps. We applied the method to a case study using the fungal isolate ICIPE 62 to control the invasive fruit fly Bactrocera dorsalis. The research revealed that nine pheromone traps per ha are required with a spacing distance of 37.45 m between the traps. The proposed approach can also be applied to other pest species, to help farmers reduce the number of traps used on a farm and to assist researchers and policymakers to optimize auto dissemination strategies in the context of integrated pest management (IPM).     

Increased microclimatic variation in artificial nests does not create ecological traps for a secondary cavity breeder,the European roller

Artificial devices are increasingly used in conservation measures to mitigate the disappearance of natural habitats. However, few studies have demonstrated their benefits for the target species, and they may pose a risk of creating ecological traps. This occurs when lower individual fitness is found in artificial habitats that are more attractive than their natural equivalents. In this study, we tested the ecological trap hypothesis on a dense population of European rollers Coracias garrulus breeding in both natural cavities and nest boxes. Our initial prediction was that the more stressful microclimatic conditions of nest boxes would lead to reduced fitness of European rollers, thus creating an ecological trap. The results showed that nest boxes were preferred over natural cavities. Despite significantly more extreme microclimatic conditions in nest boxes, we found similar breeding parameters between artificial and natural nest types. Our results also suggest that European rollers selected the nest boxes which best buffered the temperature, thus avoiding potential ecological traps. Overall our results led to the conclusion that nest boxes do not create ecological traps for European rollers in this study area. However, other species may be more sensitive to microclimatic variations or less able to avoid the least favorable nest boxes. These findings could help to inform the placement of nest boxes in order to reduce extreme temperatures and variation in humidity rates. Future studies could compare nest types for other fitness parameters, such as juvenile body condition or survival. We also recommend the ecological trap hypothesis as a useful framework to evaluate the outcomes of artificial devices used for conservation.     

Advancing Primate Research and Conservation Through the Use of Camera Traps: Introduction to the Special Issue

Effective conservation and management of primates depend on our ability to accurately assess and monitor populations through research. Camera traps are proving to be useful tools for studying a variety of primate species, in diverse and often difficult habitats. Here, we discuss the use of camera traps in primatology to survey rare species, assess populations, and record behavior. We also discuss methodological considerations for primate studies, including camera trap research design, inherent biases, and some limitations of camera traps. We encourage other primatologists to use transparent and standardized methods, and when appropriate to consider using occupancy framework to account for imperfect detection, and complementary techniques, e.g., transect counts, interviews, behavioral observation, to ensure accuracy of data interpretation. In addition, we address the conservation implications of camera trapping, such as using data to inform industry, garner public support, and contributing photos to large-scale habitat monitoring projects. Camera trap studies such as these are sure to advance research and conservation of primate species. Finally, we provide commentary on the ethical considerations, e.g., photographs of humans and illegal activity, of using camera traps in primate research. We believe ethical considerations will be particularly important in future primate studies, although this topic has not previously been addressed for camera trap use in primatology or any wildlife species.     

Habitat Selection of Rocky Mountain Elk in a Nonforested Environment

Abstract: Recent expansions by Rocky Mountain elk (Cervus elaphus) into nonforested habitats across the Intermountain West have required managers to reconsider the traditional paradigms of forage and cover as they relate to managing elk and their habitats. We examined seasonal habitat selection patterns of a hunted elk population in a nonforested high-desert region of southwestern Wyoming, USA. We used 35,246 global positioning system locations collected from 33 adult female elk to model probability of use as a function of 6 habitat variables: slope, aspect, elevation, habitat diversity, distance to shrub cover, and distance to road. We developed resource selection probability functions for individual elk, and then we averaged the coefficients to estimate population-level models for summer and winter periods. We used the population-level models to generate predictive maps by assigning pixels across the study area to 1 of 4 use categories (i.e., high, medium-high, medium-low, or low), based on quartiles of the predictions. Model coefficients and predictive maps indicated that elk selected for summer habitats characterized by higher elevations in areas of high vegetative diversity, close to shrub cover, northerly aspects, moderate slopes, and away from roads. Winter habitat selection patterns were similar, except elk shifted to areas with lower elevations and southerly aspects. We validated predictive maps by using 528 locations collected from an independent sample of radiomarked elk (n = 55) and calculating the proportion of locations that occurred in each of the 4 use categories. Together, the high- and medium-high use categories of the summer and winter predictive maps contained 92% and 74% of summer and winter elk locations, respectively. Our population-level models and associated predictive maps were successful in predicting winter and summer habitat use by elk in a nonforested environment. In the absence of forest cover, elk seemed to rely on a combination of shrubs, topography, and low human disturbance to meet their thermal and hiding cover requirements.     

The evolution of redd site selection in brook charr in different environments: same cue,same benefit for fitness*

1. Despite the great interest in characterising fish reproductive habitat, the relationship between the selection of a given spawning site and individual fitness has not been experimentally tested. 2. In this study, we used an in situ experimental approach to determine (i) the relative contribution of substrate characteristics as well as hydrological and physicochemical variables to small‐scale redd site selection by brook charr, Salvelinus fontinalis (Mitchill) and (ii) if hatching and emergence success, used as a surrogate of fitness, are improved in selected compared to non‐selected sites in both lake and stream habitats. 3. Our results show that upwelling groundwater flow was always significantly higher in selected than in non‐selected sites in both lake and stream habitats. We found no significant difference in the mean geometric substrate diameter and no consistent differences in substrate composition between selected and non‐selected sites. Oxygen concentration was higher (significantly so in three of four comparisons) and conductivity tended to be lower in selected than in non‐selected sites, while temperature showed no significant or consistent variations. We found a significant positive relationship between the selection of a given spawning habitat and hatching and emergence success in these systems. 4. These results show that the main cue that brook charr use to select their spawning sites is upwelling groundwater in lake and stream habitats, and that active selection of these sites increases individual fitness. This suggests that natural selection acted on the same cues in lentic and lotic environments; this could have been highly adaptive in a species that used both habitats as colonisation routes after the last glaciation.     

Changing light conditions in pine rockland habitats affect the intensity and outcome of ant–plant interactions

Extrafloral nectar (EFN) mediates food‐for‐protection mutualisms between plants and ants. Such mutualisms exist within a complex web of biotic interactions, and in a framework provided by the abiotic environment. Both biotic and abiotic factors, therefore, affect the outcome of ant–plant interactions. We conducted an experiment to determine the effects of ant activity, and light intensity, on herbivory rates, growth, and reproductive fitness in Senna mexicana var. chapmanii, a perennial legume native to pine rockland habitats of south Florida. Forty plants were divided among four treatments in a factorial experimental design with two independent variables: ant activity and light intensity. Plants were divided equally between sunny and shady habitats, and ants were excluded from half of the plants in each habitat type. The presence of ants significantly reduced herbivory rates in S. chapmanii. In shaded habitats, the presence of ants had no effect on plant reproductive fitness, however, in sunny habitats plants with ants produced significantly more seeds over the duration of the 1‐yr study. Ants represent an important biotic defense against herbivores in S. chapmanii; however, their effects on plant fitness are dependent on light conditions. Pine rockland habitats in south Florida have been widely destroyed or mismanaged. In fragments that remain, suppression of fire has led to increased canopy closure and shading of the understory. These changes will likely negatively impact plants that rely on ants for defense. We highlight the importance of conservation efforts to preserve the pine rocklands and the fire regimes on which they rely.     

Behavioral plasticity and consistency in the naked-footed mouse (<Emphasis Type="Italic">Peromyscus nudipes</Emphasis>) with habitat disturbance

Very few studies have evaluated whether habitat disturbance affects behavioral consistency and plasticity. We measured shyness–boldness and exploration–avoidance for the first time in naked-footed mice (Peromyscus nudipes) in two adjacent habitats with differing level of disturbance in Costa Rica. Each habitat was measured in different, consecutive years. With these data, we explored the possibility of habitat differences in individual- and population-level behavioral plasticity, magnitude of behavior, and consistency. Mice in both habitats behaved consistently across time with high repeatability (i.e., showed personality). The strength of consistency of shyness–boldness and exploration–avoidance over time was higher in the disturbed habitat, and individuals in the undisturbed habitat were bolder and less exploratory. Behaviors were correlated with each other in both habitats, indicating that behavioral syndromes do not always break down in disturbed areas. Mice changed the magnitude of their response the second time they were tested, indicating population-level plasticity. There was also greater individual plasticity among mice in the undisturbed habitat. Our study suggests the possibility that habitat disturbance can affect behavioral plasticity and personality and that shyer/more exploratory individuals might colonize and/or persist in disturbed habitats. These results are preliminary and exploratory because we did not control for temporal differences between habitats.     

Spatio-temporal shifts in gradients of habitat quality for an opportunistic avian predator

We used the conceptual framework of the theory of natural selection to study breeding habitat preferences by an opportunistic avian predator, the black kite Milvus migrans. In Europe, black kite populations are mostly found near large networks of aquatic habitats, usually considered optimal for foraging and breeding. We hypothesized that proximity to wetlands could vary among individuals and affect their fitness, and thus be subject to natural selection. We tested the hypothesis first on a population on Lake Lugano (Italian pre‐Alps) which has been monitored for nine years, and then on seven other populations, each studied for four–five years, located along a continuum of habitat from large water bodies to scarce aquatic habitat of any kind. In the Lake Lugano population, black kite abundance was negatively related to distance to the lake in all the nine years of study, consistent with long‐term natural selection. There was evidence of ongoing directional selection on strategic nest location in three of the years, and evidence of stabilizing selection in two years. In eight of the nine years the trend was for a linear increase in fitness with increasing proximity to the lake. At the population level, results were consistent with adaptive habitat choice in relation to the previous year's spatial variation in fitness: higher associations between fitness and distance to the lake (i.e. higher selection gradients) resulted in higher density variations in the following year, in turn related to the availability of fish, the main local prey. The progressive decline of inland pairs and increase in the density of lakeshore pairs caused a directional long‐term trend of declining mean distance to the lake. Breeding near aquatic habitats was associated with higher foraging success, and higher frequency and biomass of prey deliveries to offspring. There was weak evidence of selection in other populations. The inland‐wetland gradient of habitat quality may have been affected by predation risk, as estimated by density of a major predator of adults and nestlings, the eagle owl Bubo bubo. Behavioral decisions at the level of the individual probably translated into population effects on density and distribution at various spatial scales. Populations in optimal habitats showed higher density and produced six times as many young per unit space as those in sub‐optimal habitats.     

Changing use of camera traps in mammalian field research: habitats,taxa and study types

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Consequences of habitat fragmentation for plant species: Do we know enough?

Habitat fragmentation is one of the most important causes for the decline of plant species. However, plants differing in phylogeny, habitat requirements and biology are likely to respond differently to habitat fragmentation. We ask whether case studies on the effects of habitat fragmentation conducted so far allow generalizations about its effects on the fitness and genetic diversity of populations of endangered plant species. We compared the characteristics of plant species endangered in Germany whose sensitivity to habitat fragmentation had been studied with those of the endangered species that had not been studied. We found strong discrepancies between the two groups with regard to their taxonomy and traits relevant to their sensitivity to habitat fragmentation. Monocots, graminoids, clonal, abiotically pollinated and self compatible species were underrepresented among the studied species, and most study species were from a few habitat types, in particular grasslands. We conclude that our current knowledge of the effects of habitat fragmentation on plant populations is not sufficient to provide widely applicable guidelines for species management. The selection of species studied so far has been biased toward species from certain habitats and species exhibiting traits that probably make them vulnerable to habitat fragmentation. Future studies should include community-wide approaches in different habitats, e.g. re-visitation studies in which the species pool is assessed at different time intervals, and population-biological studies of species from a wide range of habitats, and of different life forms and growth strategies. A more representative picture of the effects of habitat fragmentation would allow a better assessment of threats and more specific recommendations for optimally managing populations of endangered plants.     

Pre- and post-copulatory sexual selection increase offspring quality but impose survival costs to female field crickets

Whether sexual selection increases or decreases fitness is under ongoing debate. Sexual selection operates before and after mating. Yet, the effects of each episode of selection on individual reproductive success remain largely unexplored. We ask how disentangled pre- and post-copulatory sexual selection contribute to fitness of field crickets Gryllus bimaculatus. Treatments allowed exclusively for (i) pre-copulatory selection, with males fighting and courting one female, and the resulting pair breeding monogamously, (ii) post-copulatory selection, with females mating consecutively to multiple males and (iii) relaxed selection, with enforced pair monogamy. While standardizing the number of matings, we estimated a number of fitness traits across treatments and show that females experiencing sexual selection were more likely to reproduce, their offspring hatched sooner, developed faster and had higher body mass at adulthood, but females suffered survival costs. Interestingly, we found no differences in fitness of females or their offspring from pre- and post-copulatory sexual selection treatments. Our findings highlight the potential for sexual selection in enhancing indirect female fitness while concurrently imposing direct survival costs. By potentially outweighing these costs, increased offspring quality could lead to beneficial population-level consequences of sexual selection.     

温度升高对昆虫发生发展的影响

全世界地表平均温度在上个世纪增加了0.74℃,并且在未来还会持续增加。在过去的20年,气候变暖对生物系统的影响吸引了大量的研究。本文综述了由温度升高为主要驱动因子的气候变化对昆虫适合度的影响,主要从昆虫越冬存活率、化性(世代数)、扩散迁移、发生分布、物候关系5个方面阐述气候变暖对昆虫发生发展的作用,认为未来应长期进行昆虫种群动态监测预警,更关注气候变暖下植物-害虫-天敌互作关系的研究。     

Translocation as a novel approach to study effects of a new breeding habitat on reproductive output in wild birds

Environmental conditions under which species reproduce have major consequences on breeding success and subsequent fitness. Therefore breeding habitat choice is ultimately important. Studies rarely address the potential fitness pay-offs of alternative natural breeding habitats by experimental translocation. Here we present a new tool to study fitness consequences of free living birds in different habitats. We translocated a migratory passerine, the pied flycatcher (Ficedula hypoleuca), to a novel site, where pairs were subjected to a short stay (2-4 days) in a nest box-equipped aviary before being released. We show that it is technically possible to retain birds in the new area for breeding, allowing the study of reproductive consequences of dispersal under natural conditions. The translocation resulted in an extension of the interval between arrival and egg laying of four days, highlighting the importance of having an adequate control group. Clutch size and nestling parameters did not differ significantly between translocated and unmanipulated females, which suggests that the procedure did not affect birds in their reproductive performance later on. This method could be applied broadly in evolutionary and ecological research, e.g., to study the potential fitness benefits and costs for dispersing to more northern latitudes as a way of adapting to climate change.     

Impacts of human‐induced environmental change in wetlands on aquatic animals

Many wetlands harbour highly diverse biological communities and provide extensive ecosystem services; however, these important ecological features are being altered, degraded and destroyed around the world. Despite a wealth of research on how animals respond to anthropogenic changes to natural wetlands and how they use created wetlands, we lack a broad synthesis of these data. While some altered wetlands may provide vital habitat, others could pose a considerable risk to wildlife. This risk will be heightened if such wetlands are ecological traps – preferred habitats that confer lower fitness than another available habitat. Wetlands functioning as ecological traps could decrease both local and regional population persistence, and ultimately lead to extinctions. Most studies have examined how animals respond to changes in environmental conditions by measuring responses at the community and population levels, but studying ecological traps requires information on fitness and habitat preferences. Our current lack of knowledge of individual‐level responses may therefore limit our capacity to manage wetland ecosystems effectively since ecological traps require different management practices to mitigate potential consequences. We conducted a global meta‐analysis to characterise how animals respond to four key drivers of wetland alteration: agriculture, mining, restoration and urbanisation. Our overarching goal was to evaluate the ecological impacts of human alterations to wetland ecosystems, as well as identify current knowledge gaps that limit both the current understanding of these responses and effective wetland management. We extracted 1799 taxon‐specific response ratios from 271 studies across 29 countries. Community‐ (e.g. richness) and population‐level (e.g. density) measures within altered wetlands were largely comparable to those within reference wetlands. By contrast, individual fitness measures (e.g. survival) were often lower, highlighting the potential limitations of using only community‐ and population‐level measures to assess habitat quality. Only four studies provided habitat‐preference data, preventing investigation of the potential for altered wetlands to function as ecological traps. This is concerning because attempts to identify ecological traps may detect previously unidentified conservation risks. Although there was considerable variability amongst taxa, amphibians were typically the most sensitive taxon, and thus, may be a valuable bio‐indicator of wetland quality. Despite suffering reduced survival and reproduction, measures such as time to and mass at metamorphosis were similar between altered and reference wetlands, suggesting that quantifying metamorphosis‐related measures in isolation may not provide accurate information on habitat quality. Our review provides the most detailed evaluation to date of the ecological impacts of human alterations to wetland ecosystems. We emphasise that the role of wetlands in human‐altered ecosystems can be complex, as they may represent important habitat but also pose potential risks to animals. Reduced availability of natural wetlands is increasing the importance of altered wetlands for aquatic animals. Consequently, we need to define what represents habitat quality from the perspective of animals, and gain a greater understanding of the underlying mechanisms of habitat selection and how these factors could be manipulated. Furthermore, strategies to enhance the quality of these wetlands should be implemented to maximise their conservation potential.     

Habitat complexity drives experimental evolution of a conditionally expressed secondary sexual trait

The conditional expression of alternative phenotypes underlies the production of almost all life history decisions and many dichotomous traits, including male alternative reproductive morphs and behavioral tactics. Changes in tactic fitness should lead to evolutionary shifts in developmental switch points that underlie tactic expression. We used experimental evolution to directly test this hypothesis by rearing ten generations of the male-dimorphic mite Rhizoglyphus echinopus in either simple or three-dimensionally complex habitats that differed in their effects on morph fitness. In R. echinopus, fighter males develop weapons used for killing rivals, whereas scrambler males do not. Populations evolving in complex 3D habitats, where fighters had reduced fitness, produced fewer fighters because the switch point for fighter development evolved to a larger critical body size. Both the reduced mobility of fighter males and the altered spatial distribution of potential mates and rivals in the complex habitat were implicated in the evolutionary divergence of switch point between the habitats. Our results demonstrate how abiotic factors like habitat complexity can have a profound effect on evolution through sexual selection.     

Dynamic effects of ground-layer plant communities on beetles in a fragmented farming landscape

Vegetation effects on arthropods are well recognized, but it is unclear how different vegetation attributes might influence arthropod assemblages across mixed-agricultural landscapes. Understanding how plant communities influence arthropods under different habitat and seasonal contexts can identify vegetation management options for arthropod biodiversity. We examined relationships between vegetation structure, plant species richness and plant species composition, and the diversity and composition of beetles in different habitats and time periods. We asked: (1) What is the relative importance of plant species richness, vegetation structure and plant composition in explaining beetle species richness, activity-density and composition? (2) How do plant-beetle relationships vary between different habitats over time? We sampled beetles using pitfall traps and surveyed vegetation in three habitats (woodland, farmland, their edges) during peak crop growth in spring and post-harvest in summer. Plant composition better predicted beetle composition than vegetation structure. Both plant richness and vegetation structure significantly and positively affected beetle activity-density. The influence of all vegetation attributes often varied in strength and direction between habitats and seasons for all trophic groups. The variable nature of plant-beetle relationships suggests that vegetation management could be targeted at specific habitats and time periods to maximize positive outcomes for beetle diversity. In particular, management that promotes plant richness at edges, and promotes herbaceous cover during summer, can support beetle diversity. Conserving ground cover in all habitats may improve activity-density of all beetle trophic groups. The impacts of existing weed control strategies in Australian crop margins on arthropod biodiversity require further study.     

Optimal size and number of propagules: allowance for discrete stages and effects of maternal size on reproductive output and offspring fitness

Existing optimality models of propagule size and number are not appropriate for many organisms. First, existing models assume a monotonically increasing offspring fitness/propagule size relationship. However, offspring survival during certain stages may decrease with increasing propagule size, generating a peaked offspring fitness/propagule size function (e.g., egg size in oxygen-limited aquatic environments). Second, existing models typically do not consider maternal effects on total reproductive output and the expression of offspring survival/propagule size relationships. However, larger females often have greater total egg production and may provide better habitats for their offspring. We develop a specific optimality model that incorporates these effects and test its predictions using data from salmonid fishes. We then outline a general model without assuming specific functional forms and test its predictions using data from freshwater fishes. Our theoretical and empirical results illustrate that, when offspring survival is negatively correlated with propagule size, optimal propagule size is larger in better habitats. When larger females provide better habitats, their optimal propagule size is larger. Nevertheless, propagule number should increase more rapidly than propagule size for a given increase in maternal size. In the absence of density dependence, females with greater relative reproductive output (i.e., for a given body size) should produce more but not larger propagules.     

Evaluation of Live-Capture Techniques for Free-Ranging Wolverines

Abstract: Wolverines (Gulo gulo) are a rare carnivore and live-capture efforts often comprise a significant component of field research projects. Wolverine studies have used aerial, snowmobile, hand-capture, and live-trap capture techniques. We reviewed existing wolverine live-capture data to evaluate sex-related biases associated with capture technique. We modified round log live traps, developed a new portable wooden live trap, and evaluated effects of live trap type, trap-site selection, and seasonal timing of trapping on wolverine capture success. Aerial capture techniques had a positive bias for capture of male wolverines. Live-capture rates were highest for portable wooden traps and lowest for barrel traps. Trapping success was highest during March when snow conditions were amenable to wolverine travel and temperatures improved bait effectiveness. Traps in corridor habitats were more successful than traps in noncorridor habitats. This difference was more pronounced in environments with rugged topography. We provide guidance for live-trap operation, describe animal handling procedures, and provide detailed instructions for construction of modified round log and portable wooden wolverine live traps. These will benefit future wolverine studies by increasing trap effectiveness and reducing risk of injury and mortality to captured wolverines.