Methodologies for Surveying Herpetofauna Mortality on Rural Highways

Abstract: Road mortality can contribute to local and regional declines in amphibian and reptile populations. Thus, there is a need to accurately and efficiently identify hotspots of road-mortality for hazard assessment and mitigation. In 2002, we conducted walking and driving surveys throughout an extensive rural highway network in northern New York, USA, to evaluate survey methods and to quantify spatial and temporal patterns of herpetofauna road-mortality. In 2004, we repeated the surveys at a subset of locations to quantify interannual repeatability. Reptile and amphibian species had different peak periods of road-mortality because they differed in the causes of movements that resulted in crossings. Spatial locations of herpetofauna road-mortality were concentrated at a limited number of hotspots. Hotspots overlapped across species and were located at consistent locations across years. Results of walking and driving surveys were highly repeatable among survey teams, but driving surveys underestimated the density of road-mortality because many animals were missed. Detection failure was higher in some taxa (e.g., frogs) than others (e.g., turtles). Our results indicate that it is possible to design a valid, efficient methodology for locating hotspots of reptile and amphibian road-mortality along a road network and, thus, pinpoint priority sites for mitigation.     

Road mortality in freshwater turtles: identifying causes of spatial patterns to optimize road planning and mitigation

Road mortality of freshwater turtles can be high enough to imperil populations near roads, thus there is a need to efficiently and accurately locate regions of excessive road-kill along road networks for mitigation. Weekly over 2?years, we drove a 160?km highway circuit in northeastern New York State, USA and recorded the location of all detected road-kill of three freshwater turtle species (Chelydra serpentina, Chrysemys picta, Emydoidea blandingii). We then analyzed the spatial dispersion of road-kill and the road and landscape features associated with road-kill locations. Road-kill was most prevalent at a limited number of short road segments, termed ‘hotspots’. The locations of hotspots, as indicated by kernel density analysis, and the peak spatial extent of hotspots (250?m), as indicated by Ripley’s?K, corresponded to the locations and average lengths of causeways (road segments with wetlands within 100?m on both sides). Hotspots were located at causeways that were greater than 200?m length and characterized by high traffic volumes, close proximity to water, and high forest coverage. We conclude that freshwater turtle road mortality is spatially aggregated at short, severe hotspots, and hotspot locations can be predicted when the locations of wetlands, traffic volumes, and the land-uses bordering roads are known. Hotspot models using these predictors can locate sites along a road network that are the most promising for mitigation to reduce excessive road mortality and maintain connectivity.     

Predicting Hot Spots of Herpetofauna Road Mortality Along Highway Networks

ABSTRACT Road mortality is often spatially aggregated, and there is a need for models that accurately and efficiently predict hot spots within a road network for mitigation. We surveyed 145 points throughout a 353-km highway network in New York State, USA, for roadkill of reptiles and amphibians. We used land cover, wetland configuration, and traffic volume data to identify features that best predicted hot spots of herpetofauna road mortality. We resampled 40 points an additional 4 times over 4 years to evaluate temporal repeatability. Both amphibian and reptile road mortality were spatially clustered, and road-kill hot spots of the 2 taxa overlapped. One survey provided a valid snapshot of spatial patterns of road mortality, and spatial patterns remained stable across time. Road-kill hot spots were located where wetlands approached within 100 m of the road, and the best predictor was a causeway configuration of wetlands (wetlands on both sides of the road). We validated causeways as predictors of road mortality by surveying 180 causeways and 180 random points across 5 regions (17,823 km²) of northeastern New York. Causeways were 3 times more likely than random locations to have amphibian and 12 times more likely to have reptile mortality present, and causeways had a 4 times higher total number of amphibian roadkill and 9 times higher reptile roadkill than did random points. We conclude it is possible to identify valid predictors of hot spots of amphibian and reptile road mortality for use when planning roads or when conducting surveys on existing roads to locate priority areas for mitigation.     

Identification methods and deterministic factors of owl roadkill hotspot locations in Mediterranean landscapes

Road fatalities are among the major causes of mortality for Strigiformes species and may affect the population’s survival. The use of mitigation strategies must be considered to overcome this problem. However, because mitigation along the total length of all roads is not financially feasible, the locations where Strigiformes roadkills are more frequent (i.e., road fatality hotspots) must be identified. In addition to hotspot identification, factors that influence the occurrence of such fatalities should be recognized to allow mitigation measures to be delineated. We used road fatality data collected from 311 km of southern Portugal roads over a 2-year period to compare the performance of five hotspot identification methods: binary logistic regression (BLR), ecological niche factor analysis (ENFA), Kernel density estimation, nearest neighbor hierarchical clustering (NNHC), and Malo’s method. BLR and ENFA modelling were also used for recognizing roadkill deterministic factors. Our results suggest that Malo’s method should be preferred for hotspot identification. The main factors driving owl roadkillings are those associated with good habitat conditions for species occurrence and specific conditions that promote hunting behavior near roads. Based on these factors, several mitigation measures are recommended.     

Comparing Habitat Suitability and Connectivity Modeling Methods for Conserving Pronghorn Migrations

Terrestrial long-distance migrations are declining globally: in North America, nearly 75% have been lost. Yet there has been limited research comparing habitat suitability and connectivity models to identify migration corridors across increasingly fragmented landscapes. Here we use pronghorn (Antilocapra americana) migrations in prairie habitat to compare two types of models that identify habitat suitability: maximum entropy (Maxent) and expert-based (Analytic Hierarchy Process). We used distance to wells, distance to water, NDVI, land cover, distance to roads, terrain shape and fence presence to parameterize the models. We then used the output of these models as cost surfaces to compare two common connectivity models, least-cost modeling (LCM) and circuit theory. Using pronghorn movement data from spring and fall migrations, we identified potential migration corridors by combining each habitat suitability model with each connectivity model. The best performing model combination was Maxent with LCM corridors across both seasons. Maxent out-performed expert-based habitat suitability models for both spring and fall migrations. However, expert-based corridors can perform relatively well and are a cost-effective alternative if species location data are unavailable. Corridors created using LCM out-performed circuit theory, as measured by the number of pronghorn GPS locations present within the corridors. We suggest the use of a tiered approach using different corridor widths for prioritizing conservation and mitigation actions, such as fence removal or conservation easements.     

Spatial distribution of road-kills and factors influencing road mortality for mammals in Northern New York State

One of the most obvious impacts of roads on wildlife is vehicle-induced mortality. The aims of this study were to examine the spatial pattern of mammal–vehicle collisions (MVCs), identify and examine factors that contribute to MVCs, and determine whether the factors that increase the odds of MVCs are similar between species. On 103 road surveys that covered 7,094 total km I recorded the location of each MVC along the survey route. I measured landscape and roadway features associated with each MVC and used kernel density and network analysis tools to identify road mortality hotspots and measure spatial clustering of MVCs. I used logistic regression to model the likelihood of MVCs for all mammal data and separately for Porcupine (Erethizon dorsatum), Raccoon (Procyon lotor), Skunk (Mephitis mephitis), Muskrat (Ondatra zibethicus) and Cottontail (Sylvilagus floridanus) data sets. I identified 51 MVC hotspots and found spatial clustering of MVCs for Porcupines, Raccoons and Skunks. Two landscape variables, distance to cover and the presence of an ecotone, as well as one road variable, road width, appeared as broadly important predictors of mammalian road mortality, though there was also species-specific variation in factors that increased the risk of MVCs. Field-measured variables were more important than remotely-measured variables in predicting the odds of MVCs. Conservation implications are that mitigation of landscape features associated with higher risk of vehicle-collisions may reduce the number of MVCs in general, but species-specific research is required to more carefully tailor mitigation efforts for particular species.     

Do Roads Reduce Painted Turtle (Chrysemys picta) Populations?

Road mortality is thought to be a leading cause of turtle population decline. However, empirical evidence of the direct negative effects of road mortality on turtle population abundance is lacking. The purpose of this study was to provide a strong test of the prediction that roads reduce turtle population abundance. While controlling for potentially confounding variables, we compared relative abundance of painted turtles (Chrysemys picta) in 20 ponds in Eastern Ontario, 10 as close as possible to high traffic roads (Road sites) and 10 as far as possible from any major roads (No Road sites). There was no significant effect of roads on painted turtle relative abundance. Furthermore, our data do not support other predictions of the road mortality hypothesis; we observed neither a higher relative frequency of males to females at Road sites than at No Road sites, nor a lower average body size of turtles at Road than at No Road sites. We speculate that, although roads can cause substantial adult mortality in turtles, other factors, such as release from predation on adults and/or nests close to roads counter the negative effect of road mortality in some populations. We suggest that road mitigation for painted turtles can be limited to locations where turtles are forced to migrate across high traffic roads due, for example, to destruction of local nesting habitat or seasonal drying of ponds. This conclusion should not be extrapolated to other species of turtles, where road mortality could have a larger population-level effect than on painted turtles.     

Application of KDE+ software to identify collective risk hotspots of ungulate-vehicle collisions in South Tyrol,Northern Italy

This paper is the first dealing with animal-vehicle collisions (AVC) with red and roe deer in South Tyrol, Northern Italy. The Autonomous Province of Bolzano (South Tyrol) has been collecting AVC data since 2012 on the entire provincial road network. Each year, AVC data accounted for more than 700 cases per year, with several socioeconomic and ecological implications. The aim of this research is to identify the locations where AVC occur more frequently than expected (hotspots) and better outline subsequent implementation of mitigation measures. For an effective identification of AVC hotspots, we applied a combined methodology of temporal and spatial analysis on AVC data collected on the South Tyrol road network in the years 2012–2014. AVC data enabled the identification of the temporal patterns, which showed different behaviors of the two target species in close proximity of the road network and throughout the 12 months. The KDE+ software applied to the 2012–2014 AVC database allowed for spatial analysis and the identification of hotspots, i.e., the road sections having the highest risk for drivers. The integration of the results, coming from the abovementioned methodologies, contributes to a detailed assessment of roads that would allow the identification of the local contributing factors and a base-line of potential problematic areas that will highlight the need for further investigation to assess whether the risk-rank is accurate and allocate effectively limited resources to a feasible number of identified hotspots and reduce the current degree of AVC in the South Tyrolean road network.     

Moose Movement Rates Along Highways and Crossing Probability Models

ABSTRACT We developed and validated a density-adjusted spatial model to predict moose (Alces alces) highway-crossing probability to see if the model could be used as an index of moose-vehicle collision risk. We installed Global Positioning System telemetry collars on 47 moose in the north of the Laurentides Wildlife Reserve, Québec, for 2–36 months. We recorded only 84 highway crossings in spring (0.29% of 28,967 2-hr steps) and 122 crossings in summer (0.18% of 68,337 2-hr steps), despite a high sampling effort and having captured moose close to highways. Moose movement rates during movement steps crossing a highway were on average 3 times higher than during the steps preceding or following highway crossing. Paths used by moose when crossing a highway were characterized by a high proportion of food stands, low proportion of lakes and rivers, and topography typical of a valley. Highway-crossing sites were located in valleys with brackish pools and forest stands providing coniferous cover but a low proportion of lakes and rivers. We adjusted moose crossing probability for local variation in moose density using aerial survey data and assessed crossing probability along the highways in the entire Laurentides Wildlife Reserve. We tested the model using moose-vehicle accident data from 1990 to 2002. The relationship between the density-adjusted crossing probability and number of accidents was relatively loose at the 1-km scale but improved markedly when using longer highway sections (5–15 km; r > 0.80). Our results demonstrate that roads and their surroundings are perceived as low-quality habitat by moose. We also conclude that road segments installed along secondary valleys could be a highly strategic site to deploy mitigation measures such as fences and that it could be desirable to increase the width of road shoulders to reduce forest cover and to eliminate brackish pools to reduce cervid-vehicle collisions. We suggest using empirical data such as location of vehicle-wildlife collisions to plan mitigation measures at a fine scale.     

Vehicle–wild vertebrate collision mortality on the highways of Tigray,Ethiopia, implications for conservation

In view of the upcoming road network improvement and expansion in Ethiopia, specifically in Tigray, it is also necessary to understand the potential impacts of road accidents with wildlife vertebrate animals. Road mortality detection surveys were conducted from March 2013 to June 2014. We surveyed around 530 km using vehicle with special emphasis given to roads surrounded by wetlands, forests, rocky areas and rivers each month. Additional information was also collected using a standardized questionnaire. A total of twenty species, 143 individuals of amphibians, reptiles, birds and mammals were recorded as road vehicular accidents in the surveyed area. Of all, mammals showed the highest species richness (80 individuals belonging to ten species) followed by birds (49 individuals belonging to eight species). The survey revealed most accidents happened during the early morning and late evening. This might be due to relatively high traffic and continued activity of wild animals at that time, besides the driver's inability to avoid accidents when it is dark. Wildlife underpasses during road construction, location of crossing structures, rules of wildlife conservation, improving driver's awareness are relevant in this context and may be the most important mitigation measures to reduce mortality of wildlife on the roads.     

Incorporating habitat use in models of fauna fatalities on roads

Aim  To highlight the benefit of using habitat use to improve the accuracy of predictive road fatality models.
Location  The Snowy Mountains Highway in southern New South Wales, Australia.
Methods  A binary logistic regression model was constructed using wombat fatality presences and randomly generated absences. Species-specific habitat variables were included as predictors in the model selection process as well as two spatially explicit measures of wombat habitat use. Generalized additive models (GAMs) were constructed for each possible combination of predictors in R. The final model was selected by comparing all models subsets for the eight predictors and employing the one standard error rule to select the best model set.
Results  The final predictive model had high discriminatory power and incorporated both measures of species habitat use, greatly exceeding the variation explained by a previously published model for the same species and road.
Main Conclusions  Our findings highlight the importance of incorporating variables that describe habitat use by fauna for predictive modelling of animal-vehicle crashes. Reliance upon models that ignore landscape patterns are limited in their capacity to identify hotspots and inform managers of locations to engage in mitigation.     

Restoring Connectivity in Landscapes Fragmented by Major Roads: A Case Study Using Wooden Poles as “Stepping Stones” for Gliding Mammals

Tree‐dwelling mammals may be vulnerable to road mortality if forced to cross canopy gaps on the ground. This group of mammals has received scant attention worldwide despite major road projects potentially causing severe fragmentation to their habitat. Gliding mammals may be enabled to cross road gaps that exceed their gliding capability by the installation of tall wooden poles to act as “stepping stones.” We investigated whether such glide poles installed across two land‐bridges in eastern Australia could restore landscape connectivity for small gliding petaurid marsupials. Hair‐traps revealed repeated use of all poles at both locations over periods of 1–3 years. Camera traps at one site suggest a crossing frequency on the poles by the squirrel glider (Petaurus norfolcensis) of once every 3.8 nights. Radio‐tracked animals did not glide directly over the road but instead used the poles to cross on the bridge. Hair‐traps and camera traps installed within the middle of two reference land‐bridges that lacked glide poles failed to detect crossings by gliding mammals despite their presence in adjacent forest. These observations suggest that glide poles can facilitate road crossing and thereby restore habitat connectivity for gliding mammals. This lends support to the notion that glide poles have the potential to mitigate road‐induced habitat fragmentation for gliding mammals worldwide.     

Rapid assessment of linear transport infrastructure in relation to the impact on landscape continuity for large ranging mammals

Many Eastern European countries still host landscapes with high value due to their habitat quality and size. Some of these countries are new member states of the European Union, and EU-accession is accompanied by huge investments in the development of traffic infrastructure. Environmental assessments mandatory for road constructions in the EU do not necessarily require explicit measures for the mitigation of fragmentation, and technical constructions associated with road building are frequently assumed to provide sufficient possibilities for wildlife crossings. We evaluated those technical structures at two motorway sections separating relevant subpopulations of the brown bear (Ursus arctos) in Bulgaria. Our assessment revealed that the permeability of the two motorways has been considerably overestimated. A total of just 13 out of the 77 potential crossing possibilities of the two roads together meet the requirements we defined for suitable wildlife crossings. We found that the potential for improvement of the crossing functionality of already existing technical facilities along the motorways is very limited. Given the dependence on a small number of habitat paths connecting suitable crossings with habitat on both sides of the road, connectivity between subpopulations is vulnerable to fragmentation impacts.     

Road avoidance and its energetic consequences for reptiles

Roads are one of the most widespread human‐caused habitat modifications that can increase wildlife mortality rates and alter behavior. Roads can act as barriers with variable permeability to movement and can increase distances wildlife travel to access habitats. Movement is energetically costly, and avoidance of roads could therefore impact an animal's energy budget. We tested whether reptiles avoid roads or road crossings and explored whether the energetic consequences of road avoidance decreased individual fitness. Using telemetry data from Blanding's turtles (Emydoidea blandingii; 11,658 locations of 286 turtles from 15 sites) and eastern massasaugas (Sistrurus catenatus; 1,868 locations of 49 snakes from 3 sites), we compared frequency of observed road crossings and use of road‐adjacent habitat by reptiles to expected frequencies based on simulated correlated random walks. Turtles and snakes did not avoid habitats near roads, but both species avoided road crossings. Compared with simulations, turtles made fewer crossings of paved roads with low speed limits and more crossings of paved roads with high speed limits. Snakes made fewer crossings of all road types than expected based on simulated paths. Turtles traveled longer daily distances when their home range contained roads, but the predicted energetic cost was negligible: substantially less than the cost of producing one egg. Snakes with roads in their home range did not travel further per day than snakes without roads in their home range. We found that turtles and snakes avoided crossing roads, but road avoidance is unlikely to impact fitness through energetic expenditures. Therefore, mortality from vehicle strikes remains the most significant impact of roads on reptile populations.     

The use of habitat components by small mammals in eastern Australia

The effect of habitat components (vegetation density at two levels, litter, logs and roads) on the distribution of small mammals was assessed in adjacent areas of native forest and Pinus taeda plantation in north-eastern New South Wales. Rattus fuscipes was associated with structural complexity in native forest but not in pine plantation where it was found on downslope areas. R. rattus was associated with windrows in the pine plantation, R. lutreolus with areas devoid of a shrub layer in the pine plantation, Antechinus stuartii with logs and Melomys cervinipes with habitat components associated with rainforest areas. Road crossing by small mammals was inversely related to road width; roads severely restricted or stopped the movement of small mammals even when the road consisted of a long-unused and partly overgrown track.     

Evaluating the effectiveness of road mitigation measures

The last 20 years have seen a dramatic increase in efforts to mitigate the negative effects of roads and traffic on wildlife, including fencing to prevent wildlife-vehicle collisions and wildlife crossing structures to facilitate landscape connectivity. While not necessarily explicitly articulated, the fundamental drivers behind road mitigation are human safety, animal welfare, and/or wildlife conservation. Concomitant with the increased effort to mitigate has been a focus on evaluating road mitigation. So far, research has mainly focussed on assessing the use of wildlife crossing structures, demonstrating that a broad range of species use them. However, this research has done little to address the question of the effectiveness of crossing structures, because use of a wildlife crossing structure does not necessarily equate to its effectiveness. The paucity of studies directly examining the effectiveness of crossing structures is exacerbated by the fact that such studies are often poorly designed, which limits the level of inference that can be made. Without well performed evaluations of the effectiveness of road mitigation measures, we may endanger the viability of wildlife populations and inefficiently use financial resources by installing structures that are not as effective as we think they are. In this paper we outline the essential elements of a good experimental design for such assessments and prioritize the parameters to be measured. The framework we propose will facilitate collaboration between road agencies and scientists to undertake research programs that fully evaluate effectiveness of road mitigation measures. We discuss the added value of road mitigation evaluations for policy makers and transportation agencies and provide recommendations on how to incorporate such evaluations in road planning practices.     

Effects of Barriers and Thermal Refugia on Local Movement of the Threatened Leopard Darter, Percina pantherina

Local, short-term dispersal by the U.S. federally-threatened leopard darter, Percina pantherina, was examined in the field and in the laboratory to assess the possible effects of natural versus man-made barriers on movement. Mark-resight studies were conducted in two summers at sites in the Glover River (southeastern Oklahoma, U.S.A.). At one site, patches of 'preferred' habitat were separated by a natural riffle; at the other site, by a low-water road crossing with culverts. At the Natural Riffle site, darters moved downstream across the riffle, but also moved upstream into deeper water when water temperatures exceeded 29°C in the `preferred' habitat. Use of deeper, cooler waters by this species in late summer suggests that thermal refugia may be important habitats for the long-term management of leopard darters. At the Road Crossing site, all documented movement was in a downstream direction, and at least two darters traversed culverts in the low-water bridge. Laboratory studies of movement across several types of culverts suggested that culverts significantly decrease the probability of movement among habitat patches.     

Biogeography of the Shimba Hills ecosystem herpetofauna in Kenya

The Shimba Hills ecosystem along the south coast of Kenya is a key East African biodiversity hotspot.Historically, it is biogeographically assignable to the East African coastal biome. We examined the current Shimba Hills herpetofauna and their zoogeographical affinities to the coastal forests and nearby Eastern Arc Mountains biodiversity hotspots.The key studied sites included the Shimba Hills National Reserve, forest reserves, Kaya forests, and adjacent private land. Data on herpetofaunal richness were obtained from recent field surveys,literature, and specimens held at the National Museums of Kenya, Herpetology Section Collection,Nairobi. The Makadara, Mwele, and LongoMwagandi forests within the Shimba Hills National Reserve hosted the highest number of unique and rare species. Generally, the forest reserves and Kaya forests were important refuges for forestassociated species. On private land, Mukurumudzi Dam riparian areas were the best amphibian habitat and were host to three IUCN(Red List) EndangeredEN amphibian species, namely, Boulengerula changamwensis, Hyperolius rubrovermiculatus, and Afrixalus sylvaticus, as well as one snake species Elapsoidea nigra. Using herpetofauna as zoogeographic indicators, the Shimba Hills were determined to be at a crossroads between the coastal forests(13 endemic species) and the Eastern Arc Mountains(seven endemic species).Most of the Eastern Arc Mountains endemic species were from recent records, and thus more are likely to be found in the future. This 'hybrid' species richness pattern is attributable to the hilly topography of the Shimba Hills and their proximity to the Indian Ocean.This has contributed to the Shimba Hills being the richest herpetofauna area in Kenya, with a total of 89 and 38 reptile and amphibian species, respectively.Because of its unique zoogeography, the Shimba Hills ecosystem is undoubtedly a key biodiversity area for conservation investment.     

Disentangle the Causes of the Road Barrier Effect in Small Mammals through Genetic Patterns

Road barrier effect is among the foremost negative impacts of roads on wildlife. Knowledge of the factors responsible for the road barrier effect is crucial to understand and predict species’ responses to roads, and to improve mitigation measures in the context of management and conservation. We built a set of hypothesis aiming to infer the most probable cause of road barrier effect (traffic effect or road surface avoidance), while controlling for the potentially confounding effects road width, traffic volume and road age. The wood mouse Apodemus sylvaticus was used as a model species of small and forest-dwelling mammals, which are more likely to be affected by gaps in cover such as those resulting from road construction. We confront genetic patterns from opposite and same roadsides from samples of three highways and used computer simulations to infer migration rates between opposite roadsides. Genetic patterns from 302 samples (ca. 100 per highway) suggest that the highway barrier effect for wood mouse is due to road surface avoidance. However, from the simulations we estimated a migration rate of about 5% between opposite roadsides, indicating that some limited gene flow across highways does occur. To reduce highway impact on population genetic diversity and structure, possible mitigation measures could include retrofitting of culverts and underpasses to increase their attractiveness and facilitate their use by wood mice and other species, and setting aside roadside strips without vegetation removal to facilitate establishment and dispersal of small mammals.     

Comparative use of active searches and artificial refuges to detect amphibians in terrestrial environments

Artificial refuges (cover boards) are commonly used to survey and monitor herpetofauna in many parts of the world. Despite the extensive use of artificial refuges in mesic environments, their effectiveness for detecting amphibians in temperate zones has rarely been examined. We compared amphibian detection probabilities between two survey methods; active searches of natural habitat and artificial refuges of three different types (corrugated steel, roofing tiles and timber railway sleepers). Our study area included five bioregions encompassing a 1180‐km latitudinal gradient across a modified, temperate eucalypt woodland vegetation community in south‐eastern Australia. We deployed 14 778 artificial refuges in terrestrial environments, within patches of remnant vegetation, and collected presence and abundance data on herpetofauna between 1999 and 2017. We used Bayesian logistic regression to identify the most effective survey method for detecting frog species across all bioregions. We modelled frog detections by fitting survey method, time since refuge deployment and rainfall prior to each survey. We detected 3970 individuals from 18 frog species. Overall, we found active searches and timber substrates most effective for detecting a broad range of species, although detection rates were driven by the numerically abundant spotted marsh frog Limnodynastes tasmaniensis. Timber refuges were effective for detecting several burrowing species, whereas active searches were effective at detecting habitat generalists. Quadratic effects of rainfall prior to survey as opposed to linear effects of time since artificial refuge placement was important in explaining frog detection rates in some bioregions. Active searches, timber railway sleepers and sheets of corrugated steel provide complimentary survey methods for detecting amphibians, although detection rates are influenced by rainfall patterns. Artificial refuges provide a time‐effective and standardized method for studying amphibians in their non‐breeding terrestrial environment and should be incorporated into future surveys and biodiversity monitoring programmes.