Wildlife Mortality Research Articles

Dos registros de atropellamiento de Leopardus wiedii y Herpailurus yagouaroundi (carnivora: felidae) en Yucatán, México

La mortalidad de la fauna silvestre debido a la colisión con vehículos es un problema poco estudiado. En México, se ha incrementado el interés por determinar los efectos negativos y las acciones de mitigación ante el impacto de las redes viales sobre las poblaciones de vertebrados silvestres. En este estudio se documentan dos casos del aparente atropellamiento de un individuo de jaguarundi y uno de tigrillo, en carreteras estatales de la región litoral centro del estado de Yucatán, México. Ambos registros ponen de manifiesto la importancia de estudios que cuantifiquen el atropellamiento de vertebrados en carreteras para planificar su mitigación.

Disease's hidden death toll: Using parasite aggregation patterns to quantify landscape-level host mortality in a wildlife system.

World-wide, infectious diseases represent a major source of mortality in humans and livestock. For wildlife populations, disease-induced mortality is likely even greater, but remains notoriously difficult to estimate-especially for endemic infections. Approaches for quantifying wildlife mortality due to endemic infections have historically been limited by an inability to directly observe wildlife mortality in nature. Here we address a question that can rarely be answered for endemic pathogens of wildlife: what are the population- and landscape-level effects of infection on host mortality? We combined laboratory experiments, extensive field data and novel mathematical models to indirectly estimate the magnitude of mortality induced by an endemic, virulent trematode parasite (Ribeiroia ondatrae) on hundreds of amphibian populations spanning four native species. We developed a flexible statistical model that uses patterns of aggregation in parasite abundance to infer host mortality. Our model improves on previous approaches for inferring host mortality from parasite abundance data by (i) relaxing restrictive assumptions on the timing of host mortality and sampling, (ii) placing all mortality inference within a Bayesian framework to better quantify uncertainty and (iii) accommodating data from laboratory experiments and field sampling to allow for estimates and comparisons of mortality within and among host populations. Applying our approach to 301 amphibian populations, we found that trematode infection was associated with an average of between 13% and 40% population-level mortality. For three of the four amphibian species, our models predicted that some populations experienced >90% mortality due to infection, leading to mortality of thousands of amphibian larvae within a pond. At the landscape scale, the total number of amphibians predicted to succumb to infection was driven by a few high mortality sites, with fewer than 20% of sites contributing to greater than 80% of amphibian mortality on the landscape. The mortality estimates in this study provide a rare glimpse into the magnitude of effects that endemic parasites can have on wildlife populations and our theoretical framework for indirectly inferring parasite-induced mortality can be applied to other host-parasite systems to help reveal the hidden death toll of pathogens on wildlife hosts.

Impacts and Potential Mitigation of Road Mortality for Hedgehogs in Europe.

Simple SummaryThe environmental impacts of transport infrastructure are attracting substantial research focus and road-induced mortality of wildlife is perhaps the most conspicuous impact of roads. Hedgehogs are a common victim of traffic collisions in Europe and several hedgehog species are showing marked population declines across their range. This review aims to consolidate current knowledge on the impacts of road mortality on the viability of populations of the five hedgehog species in Europe and identify research gaps. Previous studies have shown that roads are a major source of mortality for hedgehogs and that individuals with greater net movement, generally males, have the greatest likelihood of mortality. Road mortality also contributes to population isolation. More research is needed into how different individuals perceive, use and cross roads, as well as the efficacy of different mitigation measures (e.g., wildlife crossing structures) designed to reduce road mortality and population isolation. Assessing whether local hedgehog populations are at risk of extirpation or further declines due to road mortality is a prerequisite for effective conservation in environments affected by continuously developing road networks.Transport infrastructure is a pervasive element in modern landscapes and continues to expand to meet the demands of a growing human population and its associated resource consumption. Road-induced mortality is often thought to be a major contributor to the marked declines of European hedgehog populations. This review synthesizes available evidence on the population-level impacts of road mortality and the threat to population viability for the five hedgehog species in Europe. Local and national studies suggest that road mortality can cause significant depletions in population sizes, predominantly removing adult males. Traffic collisions are a probable cause of fragmentation effects, subsequently undermining ecological processes such as dispersal, as well as the genetic variance and fitness of isolated populations. Further studies are necessary to improve population estimates and explicitly examine the consequences of sex- and age-specific mortality rates. Hedgehogs have been reported to use crossing structures, such as road tunnels, yet evaluations of mitigation measures for population survival probability are largely absent. This highlights the need for robust studies that consider population dynamics and genetics in response to mitigation. In light of ongoing declines of hedgehog populations, it is paramount that applied research is prioritised and integrated into a holistic spatial planning process.

Sources and reporting of oil spills and impacts on wildlife 1970-2018.

The extraction, transport, and consumption of hydrocarbons occur daily worldwide and can lead to environmental pollution and significant incidents of wildlife mortality. This review of literature and publicly available databases from 1970 to 2018 summarises records on oil spill incidents, sources of spills, and reported effects on wildlife. During this time period, millions of tonnes of oil were released from over 1700 acute oil spills, with only 312 (18%) reporting wildlife effects. The most numerous reported spill source was shipping. From this review, there are obvious global gaps in reporting of oil spills and recording of effects on wildlife. We recommend there is a global need for increased consistency of reporting and availability of data of oil spills, and wildlife impacts. This information is critical to preparedness and response procedures for industry (shipping and oil) and governments.

Does the shape of the road influences wildlife roadkills? Evidence from a highway in Central Andes of Colombia

Highway infrastructure is a source of multiple environmental problems, where wildlife roadkills is the most noticeable impact. Most of research in roadkills have focused in how different aspects as seasons, traffic density, location of roads, among others, have implications in the wildlife mortality on roads. However, little research have been developed on understanding how geometrical road design affects wildlife mortality. On a highway in the central Andes of Colombia, we tested whether the geometric design, it is horizontal alignment and vertical curves influence the mortality of vertebrate animals on the road. We determined the number of straight lines, circular, transition curves and vertical convex curves along the entire route of the highway (13.9 km), and between April 2018 and December 2019 we made 4 weekly tours in search of wildlife roadkills. With records, we related and compared groups of animal deaths and road shapes. We got 95 roadkills where reptile’s deaths were more than the 47% of total. We found no dependence in the distribution of deaths by Class of animals on the road shapes; the shape in which most deaths occurred was straight line (58 deaths). However, when the mortality rate per meter of route was obtained on the shape units, we found that the circular and transition curves presented two and three times (respectively) higher mortality rates than straight lines. Curved sections are presented as more dangerous geometric designs than straight lines for wildlife, regardless of their length on the road. Our research provides information necessary to take into account the relationship of geometric road design in the development of management and conservation plans of altered ecosystems with road infrastructure.

Temporal patterns of ungulate-vehicle collisions in Lithuania

Wildlife mortality caused by vehicles is a serious conservation and economic problem as collisions with large mammals are global, pervasive and increasing. We analysed 14,989 reports of ungulate-vehicle collisions (UVC) that occurred in Lithuania from 2002 to 2017. We analysed UVC data for four major ungulate species (roe deer, red deer, moose and wild boar) and checked for potential seasonal or daily trends. The temporal distribution of collisions was species-dependent. UVC analysis showed strong monthly and hourly pattern. Most occurrences took place before or during sunrise (dawn) and after or during sunset (dusk) during the year. In spring, the highest UVC peaks occurred early in the morning and late in the evening, while in winter these peaks occurred in late mornings and early evenings. With most UVC occurring on Fridays, daily variations were weak. We conclude that temporal variations of UVC distributions are result of a complex interaction of phenological factors and animal behaviour. The information provided in this study reinforces the knowledge on the dynamics and patterns of UVC and represents an important element for the identification of mitigation measures. Our findings suggest that efforts to reduce UVC should also focus on driver attitudes considering the seasonal and daily variations in UVC.

What attributes are relevant for drainage culverts to serve as efficient road crossing structures for mammals?

Roads increase wildlife mortality and present a movement barrier for many species. While wildlife passages have been advocated as a solution to many of the problems associated with roads, they are expensive and many roads still have none. However, roads usually have a series of drainage culverts designed to allow water to cross underneath the road, which might also be used by some mammals. This study aims to (1) determine what variables influence the number of successful passages of drainage culverts by mammals, and to (2) parse the effects that these variables have on the entry into and subsequent full passage of drainage culverts by individual mammals, using cameras and animal track stations along a 20 km stretch of autoroute 10 in Southern Quebec (Canada). Overall, 20 species were observed outside of the drainage culverts, but only about half of them were detected making full crossings. While various species were often seen outside, only animals highly tolerant to water, including raccoons (Procyon lotor) and American mink (Neovison vison), were observed fully crossing the structures with regularity, whereas the number of full crossings was small (<8) for all other species. High-water levels and use of polyethylene as a construction material were the strongest deterrents for both the number of successful passages and the probability of entry into the culverts. While several variables (e.g., water level, structure material, moon luminosity, distance to forest) influenced culvert entry, none had an influence on a mammal's probability of complete passage once it had entered. The results imply that ordinary drainage culverts are unsuitable as substitutes for designated wildlife passages for mammals. We recommend the installation of designated wildlife passages and fences, and that in places where wildlife passages are not feasible, dry ledges be installed in existing drainage culverts to better allow small and medium-sized mammals to safely cross under roads while avoiding the water inside of the culverts. To our knowledge, this study is the first to successfully combine trail cameras inside of drainage culverts with track-box data in the adjacent habitat.

Serological evidence for human exposure to Bacillus cereus biovar anthracis in the villages around Taï National Park, Côte d'Ivoire.

Bacillus cereus biovar anthracis (Bcbva) is an untypical anthrax-causing pathogen responsible for high wildlife mortality in Taï National Park (TNP), Côte d’Ivoire. However, nothing is known about its effect on the rural population living in the region bordering TNP. Contact to bushmeat is a known risk factor for exposure to a variety of zoonotic pathogens, but no human infections with Bcbva were noted so far. Therefore, we performed a retrospective seroprevalence analysis with sera from 1,386 study volunteers. We used assays which detect antibodies against the protective antigen PA, which is synthesized by both Bcbva and classic B. anthracis, and against the recently described antigen pXO2-60, a 35-kDa protein only produced by Bcbva. We found a high seroprevalence (22.37%) of antibodies against PA, and approximately half of those sera (10.46%) were also positive for the Bcbva-specific antigen pXO2-60. All sera negative for PA were also negative for antibodies against pXO2-60, confirming specificity and suitability of the PA/pXO2-60 combined serological assay. The fact that a large fraction of sera was positive for PA but negative for pXO2-60 can most likely be explained by lower immunogenicity of pXO2-60, but exposure to classic B. anthracis cannot be excluded. As only Bcbva has been detected in the TNP area so far, exposure to Bcbva can be suspected from the presence of antibodies against PA alone. In a questionnaire, most study participants reported contact to bushmeat and livestock carcasses. Unfortunately, risk factor analysis indicated that neither animal contacts, sex, age, nor country of origin were significant predictors of Bcbva seroprevalence. Nevertheless, our study added to an assessment of the distribution of Bcbva and its impact on the human population, and our data can serve to raise awareness of anthrax in the affected regions.

Limitations, lack of standardization, and recommended best practices in studies of renewable energy effects on birds and bats.

Increasing global energy demand is fostering the development of renewable energy as an alternative to fossil fuels. However, renewable energy facilities may adversely affect wildlife. Facility siting guidelines recommend or require project developers complete pre- and postconstruction wildlife surveys to predict risk and estimate effects of proposed projects. Despite this, there are no published studies that have quantified the types of surveys used or how survey types are standardized within and across facilities. We evaluated 628 peer-reviewed publications, unpublished reports, and citations, and we analyzed data from 525 of these sources (203 facilities: 193 wind and 10 solar) in the United States and Canada to determine the frequency of pre- and postconstruction surveys and whether that frequency changed over time; frequency of studies explicitly designed to allow before-after or impact-control analyses; and what types of survey data were collected during pre- and postconstruction periods and how those data types were standardized across periods and among facilities. Within our data set, postconstruction monitoring for wildlife fatalities and habitat use was a standard practice (n = 446 reports), but preconstruction estimation of baseline wildlife habitat use and mortality was less frequently reported (n = 84). Only 22% (n = 45) of the 203 facilities provided data from both pre- and postconstruction, and 29% (n = 59) had experimental study designs. Of 108 facilities at which habitat-use surveys were conducted, only 3% estimated of detection probability. Thus, the available data generally preclude comparison of biological data across construction periods and among facilities. Use of experimental study designs and following similar field protocols would improve the knowledge of how renewable energy affects wildlife. Article Impact Statement Many surveys at wind and solar facilities provide limited information on wildlife use and fatality rates.

Unsustainable anthropogenic mortality disrupts natal dispersal and promotes inbreeding in leopards.

Anthropogenic mortality of wildlife is typically inferred from measures of the absolute decline in population numbers. However, increasing evidence suggests that indirect demographic effects including changes to the age, sex, and social structure of populations, as well as the behavior of survivors, can profoundly impact population health and viability. Specifically, anthropogenic mortality of wildlife (especially when unsustainable) and fragmentation of the spatial distribution of individuals (home‐ranges) could disrupt natal dispersal mechanisms, with long‐term consequences to genetic structure, by compromising outbreeding behavior and gene flow. We investigate this threat in African leopards (Panthera pardus pardus), a polygynous felid with male‐biased natal dispersal. Using a combination of spatial (home‐range) and genetic (21 polymorphic microsatellites) data from 142 adult leopards, we contrast the structure of two South African populations with markedly different histories of anthropogenically linked mortality. Home‐range overlap, parentage assignment, and spatio‐genetic autocorrelation together show that historical exploitation of leopards in a recovering protected area has disrupted and reduced subadult male dispersal, thereby facilitating opportunistic male natal philopatry, with sons establishing territories closer to their mothers and sisters. The resultant kin‐clustering in males of this historically exploited population is comparable to that of females in a well‐protected reserve and has ultimately led to localized inbreeding. Our findings demonstrate novel evidence directly linking unsustainable anthropogenic mortality to inbreeding through disrupted dispersal in a large, solitary felid and expose the genetic consequences underlying this behavioral change. We therefore emphasize the importance of managing and mitigating the effects of unsustainable exploitation on local populations and increasing habitat fragmentation between contiguous protected areas by promoting in situ recovery and providing corridors of suitable habitat that maintain genetic connectivity.

Zwiesel bat banyangvirus, a potentially zoonotic Huaiyangshan banyangvirus (Formerly known as SFTS)\u2013like banyangvirus in Northern bats from Germany

Bats are reservoir hosts for several emerging and re-emerging viral pathogens causing morbidity and mortality in wildlife, animal stocks and humans. Various viruses within the family Phenuiviridae have been detected in bats, including the highly pathogenic Rift Valley fever virus and Malsoor virus, a novel Banyangvirus with close genetic relation to Huaiyangshan banyangvirus (BHAV)(former known as Severe fever with thrombocytopenia syndrome virus, SFTSV) and Heartland virus (HRTV), both of which have caused severe disease with fatal casualties in humans. In this study we present the whole genome of a novel Banyangvirus, named Zwiesel bat banyangvirus, revealed through deep sequencing of the Eptesicus nilssonii bat virome. The detection of the novel bat banyangvirus, which is in close phylogenetic relationship with the pathogenic HRTV and BHAV, underlines the possible impact of emerging phenuiviruses on public health.

Possible importance of carcasses for ebolavirus persistence in the ecosystem

Some outbreaks caused by ebolaviruses have been associated with wildlife mortalities in the past. Here, we discuss the possible roles played by animal carcasses during an ebolavirus outbreak. Corpses of wild animals that died due to ebolavirus infection or other reasons might be eaten by vertebrates and invertebrates, spreading live ebolaviruses to other animals, including humans. To prevent and contain an ebolavirus outbreak, not only potential reservoirs but also all organisms with a high likelihood of virus exposure need to be investigated.

A Baylisascaris Outbreak in Fox Squirrels (Sciurus niger) and Subsequent Detection of Francisella tularensis in Kansas, USA

Thorough epidemiologic investigations of wildlife mortality events are often challenging, in part because of the dynamic variables involved. In May 2011, six fox squirrels (Sciurus niger) in Clinton State Park, Kansas, US were euthanized after exhibiting clinical signs of neurologic disease. Postmortem examination of two squirrels revealed that these individuals died of Baylisascaris larva migrans, which resulted in meningoencephalitis and variable pneumonia and myocarditis. Fecal flotation of raccoon (Procyon lotor) feces collected in the area revealed Baylisascaris sp. ova, presumably Baylisascaris procyonis, in one of nine samples. Additional fox squirrel carcasses were submitted for diagnostic evaluation from eastern Kansas for 1 yr following the Baylisascaris sp. outbreak. This monitoring unexpectedly resulted in the detection of Francisella tularensis, the zoonotic pathogen that causes tularemia, in two fox squirrels. The increased attention to fox squirrel mortalities prompted by the outbreak of Baylisascaris sp. larva migrans revealed cases of tularemia that may not have been otherwise detected. Although F. tularensis is endemic in Kansas, the current distribution and prevalence of B. procyonis in raccoons and other hosts in Kansas are poorly understood. This yearlong mortality investigation illustrated the importance of wildlife health monitoring as a means of assessing public health risks, especially during unusual wildlife mortality events.

Anthropogenic mortality in mammals increases with the human footprint

Over the Earth's terrestrial surface, wildlife species are adversely affected by an increasing number of anthropogenic impacts to the landscape, collectively termed the “human footprint”. However, there is limited understanding of how the human footprint influences cause‐specific mortality in wildlife. We conducted a synthesis of cause‐specific mortality of North American terrestrial mammals, compiling 247 studies that as a group determined the cause of death of 6607 adult mammals among 19,910 individuals monitored. Species lifespan as well as the interaction between lifespan and the human footprint were positively associated with the proportion of mortality attributed to anthropogenic sources. Our results indicate that anthropogenic mortality in mammals increases with increasing human‐associated impacts on the landscape, and that longer‐lived species are affected more than their shorter‐lived counterparts. This pattern likely accounts for the extirpation of longer‐lived, larger‐bodied mammals from many human‐dominated areas. We also found that as the human footprint increased in magnitude, harvest mortality declined while vehicle mortality increased. These shifts in mortality can have substantial implications for understanding wildlife population dynamics and managing wildlife populations across landscapes impacted by anthropogenic activities.

Automatic detection of small PIT-tagged animals using wildlife crossings

BackgroundMitigating the effect of linear transport infrastructure (LTI) on fauna is a crucial issue in road ecology. Wildlife crossing structures (tunnels or overpasses) are one solution that has been implemented to restore habitat connectivity and reduce wildlife mortality. Evaluating how these crossings function for small wildlife has often been recommended but, mainly due to technical limitations, is not often conducted in practice or only as short-term monitoring (less than 1 year). In this study, we developed and tested an automated device that records the detailed behaviour of animals when using wildlife tunnels. The method is based on marking and detecting individuals with RFID (radio-frequency identification) tags and allows small animals to be tracked. Composed of four antennas (detectors) placed at roughly 2 m intervals, the system was tested in a tunnel in northern France in the summer of 2017. One species of amphibian (the toad Bufo spinosus, n = 13) and two carabids (the ground beetles Carabus coriaceus and Carabus nemoralis, respectively, n = 3 and n = 4), marked beforehand with PIT (passive integrated transponder) tags, were recorded when they crossed these detectors. This allowed individual trajectories, including crossing speed, to be estimated.ResultsWe found that 12 of the 13 toads and 3 of the 7 ground beetles successfully crossed the entire wildlife passage of 7 m long. The detection rate of each detector varied from 8.33 to 100%, with a mean of 52.08%. All individuals were recorded by at least one detector. We observed high variability in the crossing characteristics of toads (mean transit duration = 41 min and 15 s ± 25 min) and ground beetles (6 h 11 min ± 3 h 30 min). The system provided information on precise trajectories (e.g., crossing speed, U-turns, distance travelled in the tunnel, proportion of individuals reaching the exit, etc.) for each individual, in a context of tunnel crossing.ConclusionThe system allowed us to record small animal behaviour in the context of tunnel crossing in which other types of tracking (e.g. radio-tracking) or detection (e.g. camera traps) are not effective. It also opens the possibility for a range of experiments that would contribute to a better understanding of the behaviour of small animals in tunnels, allowing a comparison of tunnel characteristics (such as size, building material, substrate, etc.) with the aim of increasing wildlife use of the tunnel and proposing guidelines for the construction and maintenance of these mitigation measures.

Correction to 'Long-term wildlife mortality surveillance in northern Congo: a model for the detection of Ebola virus disease epizootics'.

Correction to 'Long-term wildlife mortality surveillance in northern Congo: a model for the detection of Ebola virus disease epizootics'.

Spatiotemporal railway use by grizzly bears in Canada's Rocky Mountains

ABSTRACTRailway networks contribute to the direct mortality of wildlife through collisions with trains, which can threaten vulnerable wildlife populations even in protected areas, including grizzly bears (Ursus arctos) in Banff and Yoho National Parks, Canada. Mitigation to reduce bear‐train collisions requires information about how grizzly bears use the railway spatially and temporally and how particular types of use might increase collision vulnerability. We used data from 27 grizzly bears fitted with global positioning system (GPS) collars between 2000 and 2016 to relate railway use by bears via resource selection functions to variables that described land cover, human use, and topography. We used the same suite of explanatory variables to distinguish pairs of 4 types of steps, in which 3 successive GPS points (with 2‐hr fix rates) included ≥1 within 30 m of the rail (hereafter on) and 2 others that defined locations where bears effectively entered the railway (first fix off rail, next 2 on), crossed it (only the middle fix on the rail), continued along the railway (all 3 fixes on), or exited the railway corridor (first 2 on, last off). We compared both sites of higher use and each of these 4 step types to the relative frequency of bear‐train collisions, predicting a positive correlation for continue step types. Relative to available locations, bears were more likely to use the railway close to railroad sidings (sections of twinned track where trains sometimes stop), at intermediate distances from human‐use features (e.g., town sites, highways, trails), in areas with lower values of the compound topographic index (a proxy for wetness; within 500 m), and within 90 m of rugged terrain. Seasonally, bears made greater use of the railway in spring and fall. Among 1,515 sequences of 3 steps, crossing locations comprised &gt;50% and were most distinct from continue locations (about 20%), which occurred in areas with more rugged terrain (within 300 m), closer to railway sidings, in spring and fall, and with steps that were 60% shorter. Contrary to our prediction, past reports of bear‐train collisions were negatively correlated with continue locations and unrelated to overall use or any other movement type. Our results suggest that railway use by bears increased where it provided increased forage or easier travel, particularly in spring and fall, but more work will be needed to determine the mechanistic basis of bear‐train collisions. Meanwhile, mitigation efforts such as habitat alteration or warning systems might target locations where past strikes are concentrated for grizzly bears or other sensitive populations. © 2019 The Wildlife Society.

Perceptions of Veterinarians in British Columbia of Cat Management Strategies to Reduce Cat Overpopulation and Impacts on Wildlife Populations

ABSTRACTFree-roaming cats present a multidisciplinary challenge for wildlife conservation and feline welfare. Veterinary professionals are critical stake-holders in the issue of free-roaming cats, making it imperative that their attitudes and perspectives are well understood. In this study, we conducted an electronic survey of veterinarians practicing across British Columbia to evaluate their perceptions of 1) whether cat overpopulation is a concern, 2) the impacts of cats on wildlife, and 3) alternative management strategies for dealing with cat overpopulation. Of the 389 respondents, 56% agreed that cat overpopulation was a local problem, and 91% agreed that veterinarians play a role in reducing cat overpopulation. Veterinarians in rural communities had a greater involvement in cat overpopulation and perceived it as more problematic than their urban colleagues. The majority (70%) of veterinarians reported that they performed early-age sterilization, supported the principle of low-cost spay-neuter services (67%), and 65% of them were involved in these services. Just over half (54%) of respondents reported that they provide permanent identification to cats, typically offering both microchips and tattoos. Veterinarians were less cohesive on their perceptions of the impact of free-roaming cats on wildlife: 53% agreed that after habitat loss cats are one of the most significant, direct causes of bird and wildlife mortality, while 30% were neutral and 17% disagreed. Fifty-six percent of veterinarians felt that keeping cats indoors would be one of the most effective strategies to reduce cat impacts on wildlife, but they also felt that public education programs and low-cost spay-neuter programs would be effective and more popular with cat owners. Most veterinarians (79%) recommended against unsupervised outdoor access, citing safety and disease risks. Rodent control was the most common reason for not recommending an indoor lifestyle. Overall, our survey results suggest that veterinarians are committed participants in the prevention of cat overpopulation. Conservationists need to focus on increased engagement with veterinarians regarding the impact of cats on wildlife.

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.

Long-term wildlife mortality surveillance in northern Congo: a model for the detection of Ebola virus disease epizootics.

Ebolavirus (EBOV) has caused disease outbreaks taking thousands of lives, costing billions of dollars in control efforts and threatening great ape populations. EBOV ecology is not fully understood but infected wildlife and consumption of animal carcasses have been linked to human outbreaks, especially in the Congo Basin. Partnering with the Congolese Ministry of Health, we conducted wildlife mortality surveillance and educational outreach in the northern Republic of Congo (RoC). Designed for EBOV detection and to alert public health authorities, we established a low-cost wildlife mortality reporting network covering 50 000 km2. Simultaneously, we delivered educational outreach promoting behavioural change to over 6600 people in rural northern RoC. We achieved specimen collection by training project staff on a safe sampling protocol and equipping geographically distributed bases with sampling kits. We established in-country diagnostics for EBOV testing, reducing diagnostic turnaround time to 3 days and demonstrated the absence of EBOV in 58 carcasses. Central Africa remains a high-risk EBOV region, but RoC, home to the largest remaining populations of great apes, has not had an epidemic since 2005. This effort continues to function as an untested early warning system in RoC, where people and great apes have died from past Ebola virus disease outbreaks. This article is part of the theme issue 'Dynamic and integrative approaches to understanding pathogen spillover'.