ABSTRACT In this paper, we propose an operational framework for Jaguar Conservation Units (JCUs), emphasizing the role of private rural properties in conserving jaguar populations in Brazil while mitigating human–jaguar conflicts and supporting the implementation of payments for the species' environmental services. Jaguars ( Panthera onca ) prey on domestic livestock, that can lead to retaliatory killings of jaguars by ranchers. In this context, our study aims to analyze the environmental and economic parameters associated with the ecosystem services provided by jaguars, in order to use JCUs as a starting point to develop a Payment for Environmental Services (PES) scheme to support jaguar conservation. This would involve promoting forest code compliance, maintaining habitat connectivity, and compensating cattle predation, using data from Mato Grosso do Sul (MS), Brazil. Based on spatial analyses of occurrence records, we identified and reshaped three JCUs in MS and evaluated the land use patterns within each one, discussing the basis to implement a PES scheme. Our findings demonstrate the advantages of implementing such schemes and reveal that the cost of maintaining jaguar populations through a PES, with funds from several independent sources, would be feasible and important for one of the largest jaguar populations in Brazil.
ABSTRACT Zoos and aquaria must retain genetic diversity for the species they house if the populations are to remain viable. The cryopreservation and storage of living animal cells is a potential strategy for minimising genetic diversity loss over time, when genetic diversity can be effectively reintroduced in the future as population genetic diversity decreases. Using population simulations, this study investigates the potential impact of using cryopreserved sperm on genetic diversity retention in 18 species of pupfish: a priority taxonomic group for ex‐situ conservation management for the European Association of Zoos and Aquaria (EAZA). First, genetic diversity simulations were conducted to determine the necessary population sizes required for each species to achieve a 90% genetic diversity target over a short (30‐year) or longer (100‐year) period without the integration of cryopreserved sperm into breeding management, with Ne/N simulated at either 0.05 (worst‐case scenario), 0.1 or 0.3 (best‐case scenario). Subsequently, these simulations were then compared against the required population sizes to achieve the same genetic diversity targets if cryopreserved sperm is used for 100%, 50%, 10% or 1% of breeding attempts. The simulations demonstrate that no species are currently being kept in sufficient numbers to achieve 90% genetic diversity. Specifically, the simulations projected that across the priority species ( n = 18) the average genetic diversity per species by 100 years would be 1.16% (±2.48% SD), 6.13% (±9.25% SD) and 23.57% (±25.28% SD) for Ne/N = 0.05, 0.1 and 0.3 respectively. To achieve the 90% target over 100 years, without the use of cryopreserved sperm (cryoARTs), the mean total number of fish required was 9498, 4747 and 1582 fish if Ne/N = 0.05, 0.1 or 0.3, respectively. Overall, the mean number of fish per species was 138.61 individuals (±128.61 SD) and to achieve the 90% genetic diversity target over 100 years, Ne/N = 0.3, all populations need to be increased by approximately 1400 individuals. Collectively, these scenarios demonstrate rapid loss of genetic diversity unless populations are substantially increased. Across the priority species ( n = 18), if cryoARTs is used at 10% of breeding attempts then the average total number of individual fish required to achieve the 90% genetic diversity target, for Ne/N = 0.05, 0.1 or 0.3, is 910, 455 and 152 fish respectively, over a 100‐year period. This study demonstrates that investment in greater pupfish population sizes in EAZA collections, alongside a strategy involving the integration of cryoARTs into species management, could aid in population viability by improving genetic diversity prospects.
ABSTRACT Chytridiomycosis, caused by the fungal pathogen Batrachochytrium dendrobatidis , is one of the main drivers of global amphibian declines. Among the different mitigation strategies proposed, probiotic bioaugmentation—introducing antifungal bacteria to the amphibian skin microbiome—has received considerable attention. Early laboratory and semi‐natural experiments showed promising results, raising expectations that probiotics could be used as a conservation tool in the wild. However, outcomes from subsequent studies have been highly variable, and field‐based applications have often shown limited, short‐lived or context‐dependent effects. In this essay, we critically re‐evaluate the general applicability of probiotic bioaugmentation for controlling chytridiomycosis in natural amphibian populations. We synthesize current evidence and organize the discussion around seven key limitations, grouped into biological, technical and practical dimensions. These include the high specificity and complexity of amphibian skin microbiomes, the evolutionary potential and strain‐level variability of B. dendrobatidis , ecological risks associated with introducing non‐native bacteria, difficulties in selecting effective probiotic strains, inconsistent performance under natural environmental conditions, major logistical constraints, and challenges related to scalability and long‐term sustainability. For each limitation, we briefly discuss alternative or complementary approaches, such as working with native microbial communities, habitat‐based management, postbiotics, integration with host immune responses, predictive modeling, and the promotion of natural microbial antagonists. We argue that, under current conditions, probiotics should still be regarded as an experimental and highly context‐dependent strategy rather than a robust, broadly applicable conservation tool. Overall, effective mitigation of chytridiomycosis is likely to require integrative approaches that combine microbiome research with ecological realism, careful risk assessment, and practical feasibility, rather than relying on probiotics as a standalone solution.
ABSTRACT The oil palm industry has significantly shaped global agricultural landscapes, particularly in Southeast Asia, where it is a cornerstone of economic development. However, its rapid expansion has led to widespread deforestation, habitat fragmentation and biodiversity loss, challenging sustainability goals. This review reevaluates the ecological impacts of oil palm cultivation, exploring its dual role as a threat and opportunity for wildlife conservation. Conservation efforts in oil palm ecosystems disproportionately focus on charismatic megafauna, such as orangutans and tigers, while neglecting lesser‐studied taxa like amphibians and invertebrates that play critical ecological roles. Although oil palm expansion in the long term threatens both charismatic megafauna and lesser‐studied taxa, these landscapes also present potential for biodiversity preservation through innovative land management practices. By analyzing over 800 studies, the paper highlights the underrepresentation of aquatic ecosystems and invertebrates in conservation efforts and stresses the importance of adopting multi‐taxa conservation strategies. These approaches, such as integrating agroforestry systems, restoring riparian buffers and engaging smallholders, are crucial for balancing economic productivity with ecological sustainability. The findings underscore the urgent need for targeted interventions and global cooperation to transform oil palm landscapes into biodiversity‐supporting ecosystems.
ABSTRACT The world's forests are experiencing sustained decline, yet how this chronic, non‐stand‐replacing process reshapes bird communities remains uncertain. We synthesized 382 effect sizes from 30 studies (177 species) to quantify abundance responses to forest decline and to test whether heterogeneity is better explained by functional traits, decline attributes (severity, speed, scale), and driver identity (pathogen, insect, abiotic). The pooled mean response was near zero and not distinguishable from zero, but residual heterogeneity was high, indicating strongly structured, group‐specific responses. Nesting guild emerged as the most consistently supported ecological moderator: low‐shrub/ground nesters and tree/canopy‐associated nesters showed the strongest declines, whereas responses among deadwood‐associated guilds were generally less negative and more context‐dependent. In contrast, broad diet and foraging categories had comparatively weak support across the model set, although nectarivores showed negative responses (treated as an exploratory pattern consistent with reduced floral resources). Decline attributes contributed unevenly: severity effects were generally weak, while speed‐related responses differed among drivers and spatial scale showed mixed but sometimes positive associations. Methodological factors (study design and capture method) were also among the strongest predictors of estimated effects, underscoring the importance of observation window and detectability. Overall, forest decline can reorganize avian communities without producing a uniform directional change in abundance, with potential consequences for ecosystem functions where specialized guilds decline.
Biodiversity conservation is crucial for maintaining ecosystem services, with large carnivores playing a key role in regulating prey populations and nutrient cycling. Estimating population densities is critical for conservation management, yet comparisons between realized densities and prey-based carrying capacity predictions remain scarce. We estimated realized densities of leopard (Panthera pardus) and cheetah (Acinonyx jubatus) in a woodland savanna of Namibia using spatial capture-recapture (SCR) models based on camera-trap detections. Realized leopard density was 8.6 individuals per 100 km2 (SE = 1.7). Under a wild-prey-only carrying-capacity scenario, predicted density was substantially lower at 4.0 leopards per 100 km2 (95% CI: 2.8-5.1). When livestock biomass was incorporated into the model, predicted potential density increased to 9.3 leopards per 100 km2 (95% CI: 8.95-9.82), suggesting that livestock availability may substantially elevate the ecological carrying capacity for leopards in the same study area. Cheetah detections from our camera-trap survey were insufficient for SCR estimation, with only one independent capture recorded across 660 trap-nights. Therefore, as realized cheetah density we used previously published camera-trap-derived density estimates for this landscape (1.94 individuals per 100 km2; 95% CI: 1.33-2.84). Cheetah density predicted from wild-prey biomass models was 2.08 individuals per 100 km2 (95% CI: 1.56-2.43), closely aligning with realized estimates from the same study area and suggesting that livestock availability had limited or no effect on cheetah population density. Our findings underscore the carnivore species-specific limitations of applying prey-only carrying capacity models in open, unfenced rangelands, where both wild herbivores and free-grazing livestock move freely. Incorporating both wild prey and livestock availability into carrying-capacity assessments provides a more realistic framework for understanding carnivore persistence in open systems, thereby guiding targeted management to prevent further declines of large carnivores. We recommend strengthening livestock husbandry practices to mitigate human-carnivore conflict and implementing long-term monitoring of prey availability and carnivore prey selection of wild versus domestic species, to better understand how prey dynamics influence carnivore carrying capacity and predator-prey interactions in relation to depredation conflict.
Semi-aquatic mammals lie at the intersection of several key conservation issues such as wetland deterioration or species invasions, and monitoring their distribution in space and time is essential to inform conservation strategies. However, gathering information about their presence is challenging due to their elusive lifestyle and generally low abundance. The Eurasian otter (Lutra lutra), a near-threatened and strictly protected species in Europe, is currently recolonizing part of its historical range. Its high conservation interest, combined with a dynamic more commonly associated with range-expanding or invasive species, makes it a particularly compelling case study. Otter monitoring has traditionally relied on scat surveys, but recent environmental DNA (eDNA) and camera-trapping initiatives have emerged offering promising complementary tools. Yet, these approaches have rarely been formally compared, either to one another or across regions. Here, we compared the efficiency of spraint surveys, camera traps, and eDNA for detecting otters, and assessed how their performance varied among four catchments in southern France where the species is known to be present. All three methods provided otter detections with varying efficiency. Scat surveys were the most effective method, with an average detection probability of 0.71 and no strong variability between catchments. Although camera-traps had the lowest detection rate, they provided detections at two of the four sites where no spraint was found, highlighting the complementarity of these two approaches. Detection rates varied greatly between individual cameras rather than between catchments, underscoring sensitivity to camera placement. eDNA showed important variability between catchments, with detection probabilities differing by roughly sixfold across regions. All in all, our results highlight differences in efficiency between methods and across environmental conditions, and show the value of combining approaches for future monitoring programs.
Few reintroduction and translocation programs incorporate genomic assessments into management planning, despite ongoing debate over how founder individuals should be selected. Some argue they should be genetically similar to the original population, whereas others counter-argue that their evolutionary fitness should be valued regardless of their genetic identity. Here, we assess the genomic composition of reintroduced African wild dog (Lycaon pictus) populations in private reserves in South Africa, comparing them with a free-roaming population in northern South Africa and southern Zimbabwe, and with Kruger National Park. Using genotyping-by-sequencing, mitochondrial Control Region sequences, and variation at the DLA-DRB1 Class II locus of the major histocompatibility complex, we quantified genetic diversity, population structure, gene flow, and adaptive variation. We also developed conservation translocation guidelines to inform future reintroduction efforts that are taking place across southern Africa. We show that reintroduced and free-roaming wild dogs form a single, broadly connected population, despite evidence of genetic drift, and retain high levels of adaptive genetic variation across their range compared to neutral markers. In our translocation guidelines, we recommend that wildlife managers prioritize maintaining overall genetic diversity rather than strictly preserving original genetic composition, thereby enhancing adaptive potential in a rapidly changing environment.
Roads and other linear infrastructure have detrimental impacts on wildlife populations, by fragmenting habitat, disrupting wildlife movement, and killing wildlife via collisions. Such alterations are particularly concerning for arboreal mammals, as they have been identified as disproportionately impacted by linear infrastructure relative to their terrestrial counterparts. One way to mitigate the negative effects of linear infrastructure for arboreal wildlife is to install "arboreal bridges"-structures which facilitate the movement of animals without the need for them to come to the ground. However, our understanding of the effectiveness of different arboreal bridge designs (e.g., length, bridge construction materials) remains sparse, particularly for the Neotropics, potentially limiting the effectiveness of conservation interventions. We installed 17 arboreal bridges over roads using five different designs, then evaluated their effectiveness in facilitating arboreal mammal movement using camera traps. We modeled crossing frequency as a function of bridge length, bridge height, design, local canopy cover, and time since installation. From December 2020 to June 2023, we recorded 2231 crossing events by more than 13 mammal species, including endemic, threatened, and known roadkill-affected species. Our findings reveal that bridge length and duration since installation were the strongest positive predictors of crossing activity, while denser local canopy cover negatively affected usage. Rope-based designs outperformed ladder bridges in both crossing frequency and species richness. Notably, bridge use increased consistently over a 30-month period, underscoring the importance of long-term monitoring to capture true conservation impact. These findings enhance our understanding of the use of arboreal bridges by mammals and can guide the selection of the most effective bridge design for future installations across the Neotropics. Las carreteras y otras infraestructuras lineales tienen efectos perjudiciales sobre la fauna silvestre, ya que fragmentan el h & aacute;bitat, interrumpen el movimiento de los animales y provocan su muerte por colisiones. Estas alteraciones son especialmente preocupantes para los mam & iacute;feros arbor & iacute;colas, quienes fueron identificado como desproporcionadamente afectados por la infraestructura lineal en comparaci & oacute;n con sus contrapartes terrestres. Una forma de mitigar estos efectos negativos para la fauna arbor & iacute;cola es instalar "puentes arbor & iacute;colas": estructuras que facilitan el movimiento de los animales sin necesidad de que desciendan al suelo. Sin embargo, el conocimiento sobre la efectividad de los distintos dise & ntilde;os de puentes arbor & iacute;colas (por ejemplo, longitud, materiales de construcci & oacute;n) sigue siendo limitado, especialmente en el Neotr & oacute;pico, lo que podr & iacute;a restringir el impacto de las intervenciones de conservaci & oacute;n. Instalamos puentes arbor & iacute;colas sobre carreteras en 17 ubicaciones utilizando cinco dise & ntilde;os distintos, y luego evaluamos su eficacia para facilitar el movimiento de mam & iacute;feros arbor & iacute;colas usando c & aacute;maras trampa. Modelamos la frecuencia de cruce en funci & oacute;n de la longitud del puente, su altura, el dise & ntilde;o, la cobertura de dosel local y el tiempo desde la instalaci & oacute;n. Entre diciembre de 2020 y junio de 2023, registramos 2,231 eventos de cruce por m & aacute;s de 13 especies de mam & iacute;feros, incluyendo especies end & eacute;micas, amenazadas y con alta incidencia de atropellos. Nuestros resultados revelan que la longitud del puente y el tiempo desde su instalaci & oacute;n fueron los predictores positivos m & aacute;s fuertes de la actividad de cruce, mientras que una mayor cobertura local del dosel afectaron negativamente su uso. Los dise & ntilde;os basados en cuerdas superaron a los puentes tipo escalera tanto en frecuencia de uso como en riqueza de especies. De forma destacable, el uso de los puentes aument & oacute; de manera constante durante un per & iacute;odo de 30 meses, lo que subraya la importancia del monitoreo a largo plazo para captar el verdadero impacto en conservaci & oacute;n. Estos hallazgos mejoran nuestra comprensi & oacute;n sobre el uso de los puentes arbor & iacute;colas por mam & iacute;feros y pueden orientar la selecci & oacute;n del dise & ntilde;o m & aacute;s eficaz para futuras instalaciones en la regi & oacute;n del Pac & iacute;fico Sur de Costa Rica y, en general, en todo el Neotr & oacute;pico.
Thousands of species are at risk of extinction and frequently, one lost species can lead to the loss of other co-dependent ones. Known as coextinction, this is a common but neglected form of biodiversity loss, affecting highly species-specific organisms, like parasites. One example of such specificity is the Streblidae and Nycteribiidae ectoparasitic flies and their obligate bat hosts. Here, we investigated the risk of coextinction among 106 fly and 182 bat species in Brazil, using network analysis to visualize the modularity, nestedness, and connectivity between them. Only 1/3 of the bat species had documented interactions, but 33% of the bats and 64% of the flies had species-specific links. Hosts had a higher degree of centrality (7.5) than parasites (5.0). The interaction network formed 33 distinct modules, with two to 24 species each. The average modularity (0.89) indicated a strong connection between the module nodes, but the network's structure is primarily driven by modularity and degree constraints rather than a distinct nested hierarchy. Within the modules, bats presented higher centrality values (0.25-0.75) than flies (0.25-0.5), indicating their importance in the network. Simulations of up to 100 extinction events indicated that the loss of more connected bat species would lead to a faster collapse of the network compared to null models. Four fly species are at risk of coextinction because their host species are close to or are currently threatened. In some cases, the potential extinction of a single bat species would cause five fly coextinctions. We highlight that coextinctions must be correctly considered and ignoring this would result in incorrect estimates of extinction rates and biodiversity losses. Milhares de esp & eacute;cies est & atilde;o em risco de extin & ccedil;& atilde;o e, frequentemente, a perda de uma esp & eacute;cie pode levar & agrave; perda de outras esp & eacute;cies codependentes. Conhecida como coextin & ccedil;& atilde;o, essa & eacute; uma forma comum, por & eacute;m negligenciada, de perda de biodiversidade, que afeta organismos altamente espec & iacute;ficos, como os parasitas. Um exemplo dessa especificidade s & atilde;o as moscas ectoparasitas das fam & iacute;lias Streblidae e Nycteribiidae e seus hospedeiros obrigat & oacute;rios, os morcegos. Neste estudo, investigamos o risco de coextin & ccedil;& atilde;o entre 106 esp & eacute;cies de moscas e 182 esp & eacute;cies de morcegos no Brasil, utilizando an & aacute;lise de redes para visualizar a modularidade, o aninhamento e a conectividade entre elas. Apenas 1/3 das esp & eacute;cies de morcegos apresentaram intera & ccedil;& otilde;es documentadas, mas 33% dos morcegos e 64% das moscas apresentaram liga & ccedil;& otilde;es esp & eacute;cie-espec & iacute;ficas. Os hospedeiros apresentaram maior grau de centralidade (7.5) do que os parasitas (5.0). A rede de intera & ccedil;& atilde;o formou 33 m & oacute;dulos distintos, com duas a 24 esp & eacute;cies cada. A modularidade m & eacute;dia (0.89) indicou uma forte conex & atilde;o entre os n & oacute;s dos m & oacute;dulos, mas a estrutura da rede & eacute; estruturada principalmente por restri & ccedil;& otilde;es de modularidade e grau, em vez de uma hierarquia aninhada distinta. Dentro dos m & oacute;dulos, os morcegos apresentaram valores de centralidade mais altos (0.25-0.75) do que as moscas (0.25-0.5), indicando sua import & acirc;ncia na rede. Simula & ccedil;& otilde;es de at & eacute; 100 eventos de extin & ccedil;& atilde;o indicaram que a perda de mais esp & eacute;cies de morcegos conectadas levaria a um colapso mais r & aacute;pido da rede em compara & ccedil;& atilde;o com modelos nulos. Quatro esp & eacute;cies de moscas est & atilde;o em risco de coextin & ccedil;& atilde;o porque suas esp & eacute;cies hospedeiras est & atilde;o em risco pr & oacute;ximo ou atualmente amea & ccedil;adas. Em alguns casos, a potencial extin & ccedil;& atilde;o de uma & uacute;nica esp & eacute;cie de morcego causaria a coextin & ccedil;& atilde;o de cinco esp & eacute;cies de moscas. Destacamos que as coextin & ccedil;& otilde;es devem ser consideradas corretamente e ignor & aacute;-las resultaria em estimativas incorretas das taxas de extin & ccedil;& atilde;o e perdas de biodiversidade.
Upper trophic-level predators are often a target of conservation and effective protection, and population recovery requires limiting exploitation. Maintaining prey abundance may also be critical, but we typically have little information on prey needs and how this driver compares in importance to other factors. This lack of data is true for most reef shark species, despite widespread conservation efforts. Here we consider how prey biomass affects the probability of seeing a Caribbean reef shark (Carcharhinus perezi) on reefs in The Bahamas, where establishment of a shark sanctuary in 2011 allows quantification of relatively natural spatial variability in abundance. Shark presence or absence was quantified from 631 baited remote underwater video station (BRUVS) deployments across eight island groups. We then built a model of reef fish prey biomass from 85 underwater visual surveys and 23 biophysical covariates. This model allowed predictions of prey biomass in the likely foraging areas of C. perezi around each BRUVS. A generalized linear model of C. perezi presence or absence revealed that sightings were more frequent close to reef escarpments and with increasing depth, which is consistent with known habitat use. The model also included significant terms for both mean per 4 ha and total prey biomass within foraging areas as covariates. C. perezi individuals were more commonly sighted where mean prey biomass per 4 ha was higher but, surprisingly, sightings were negatively correlated with total prey abundance (meaning sharks preferred smaller reef patches with high prey biomass). It is unclear why larger reef patches with higher total prey biomass were less used, but potential explanations include seascape context and the presence of larger-bodied sharks that may prey on C. perezi. This study highlights the need to consider managing prey abundance for effective shark conservation, particularly ensuring adequate three-dimensional reef structure upon which prey fish rely.
Nearly 70% of all primate species with available data are threatened with extinction. Hunting (i.e., wild animals either killed or live-captured) is a major contributor to primate population decline, impacting similar to 70% of all species. Using a large dataset of species' hunting status and body mass, we evaluated the spatial and phylogenetic patterns of hunting and threat status. We modeled both hunting and extinction risk as predicted by body mass and evolutionary distinctiveness (ED). We found that the subset of hunted primates is not random taxonomically or across biogeographic regions, and that the likelihood of a species being hunted increases with body mass, particularly in the American Tropics. Globally, extinction risk increased with body mass and ED. Within biogeographic regions, body mass was also related to extinction risk, and in the American Tropics evolutionarily distinct species had higher likelihoods of being threatened with extinction. In the American Tropics, 54% of species were reported to be threatened by hunting, whereas this was 70% for Africa and 89% for Asia, indicating geographic disparity in hunting patterns that could bias our results. We encourage researchers to consider the intricate relationships among species' body mass, life history traits, and hunting in conservation planning, and recommend incorporating information on local cultural hunting patterns and purposes in developing place-based conservation initiatives.
Climate change and habitat loss represent major threats to biodiversity worldwide, especially for species with narrow distributions and specific ecological requirements. Atelocynus microtis (Sclater, 1882) (Carnivora, Canidae), a forest-dependent canid endemic to the Amazon Basin, is highly sensitive to environmental disturbances, making it particularly vulnerable to ongoing climatic and land-use changes. In this study, we used species distribution models (SDMs) to evaluate the potential impacts of future climate scenarios on the distribution of A. microtis, and to assess the effectiveness of protected areas (PAs) in maintaining suitable habitats for the species. We compiled and filtered occurrence records, applied environmental and spatial thinning, and developed ensemble models using six algorithms under baseline and future climate scenarios (SSP2-4.5 and SSP5-8.5, 2061-2080). SDMs were constrained by vegetation cover and masked to the Amazon biome. Our results indicate a potential loss of 21% to 53% in suitable habitat under future climate conditions. However, despite this projected decline, approximately 53% of suitable range remains within PAs across all scenarios, far exceeding the minimum conservation target of 10% for wide-ranging species. This underscores the critical role of PAs, particularly Indigenous lands, in safeguarding Amazonian biodiversity under accelerating anthropogenic pressure. These findings reinforce the need to strengthen and maintain the integrity of conservation networks, especially in regions like the southern Amazon where projected habitat losses are most severe. Our results highlight the importance of integrating climate resilience into conservation planning to ensure long-term species survival.
Wildlife tourism is increasing globally, with a growing proportion of activities occurring in protected areas that help them generate significant revenue. Consequently, management authorities must integrate tourism into conservation planning. Such rise in human activity in these areas can adversely affect wildlife behaviour, physiology, and reproduction. A better understanding of the impact of wildlife tourism on tiger wellbeing and spatial behaviour is therefore critical for the sustainable management of these populations. We studied the effects of wildlife tourism and anthropogenic activities on stress and reproductive physiology in wild tigers across five reserves in India. We quantified faecal glucocorticoid metabolites (fGCMs), a biomarker of stress, and faecal progesterone metabolites (fPMs), an indicator of breeding activity in females. We collected 728 presumptive tiger scat samples from core and buffer zones during both tourism and non-tourism seasons, which encompass breeding periods. Genetic analysis confirmed that 610 samples originated from tigers; these were sexed and analyzed for fGCM and fPM levels. Our findings indicate that tigers exhibited higher fGCM levels in areas with high anthropogenic activity. Further, we observed spatial variation in fGCM levels that correlated with patterns of human disturbance, including tourism, suggesting a heterogeneous distribution of stressors. As human disturbance intensified in core zones, tiger fGCM levels increased and were negatively correlated with proximity to tourism roads. Furthermore, among the areas surveyed, tigresses exhibited higher fPM levels in certain locations of the reserves, where they experienced lower fGCM levels compared to other locations. This may indicate that tigresses potentially choose locations with less disturbance for breeding. Based on these results, we discuss potential management strategies to mitigate the impact of human activities on tigers and support their reproduction.
Natural and protected areas are increasingly used for outdoor recreation, with potentially negative consequences on wild mammals. Human visitation can be particularly concentrated during short periods, like weekends, especially in natural areas close to urban settings. Peaks of human presence could generate acute disturbance to wildlife, potentially affecting their temporal activity patterns or spatial distribution. To date, little evidence is available on the 'weekend effect' on mammals and current community-level research focuses only on their temporal responses. Here, we tested the spatial and temporal distribution of the medium-to-large wild mammal community in relation to day-to-day fluctuations of human activity occurring between working days and weekends. We deployed 52 camera-traps systematically within an EU Natura 2000 area located within the metropolitan area of Florence, central Italy, September-November 2022. We estimated that human visitation significantly peaked during weekends and holidays, while mammals' site-use was generally lower. Eight out of 10 mammal species seemed to spatially modulate their use of space to the fluctuations of human presence, both in relation to the rate of human passage and the proximity to roads. Conversely, we found no evidence of significant differences in temporal activity between mammals and humans during working days and weekends, as the temporal overlaps were generally low during both day types. Thus, spatial modulation of site use seems the most used short-term strategy to cope with bouts of high human visitation, with the temporal avoidance that may enable the longer-term tolerance of humans without preventing the use of preferred habitats.
Mapping species distributions with precision is fundamental to identifying their conservation needs. The International Union for Conservation of Nature (IUCN) predominantly uses geographic ranges to assign threat categories. Range maps for these assessments are often drawn from expert knowledge, but their accuracy is seldom evaluated for most taxa, particularly those that are rare and poorly studied. Using shieldtails, a group of small fossorial snakes, we demonstrate a framework for mapping distributions and evaluating threats in peninsular India. Of the 74 known shieldtail species, IUCN has evaluated only 56, with many categorised as 'Data Deficient'. To address this gap, we initiated the Shieldtail Mapping Project, a citizen science project to collect data on Indian shieldtails. By integrating citizen science observations, published literature and field and museum records, we generated geographic ranges for 12 species. We compared them to those from IUCN and the Global Assessment of Reptile Distributions (GARD). We also assessed threat exposure using three indicators: the proportion of range outside protected areas, increases in built-up areas and tree-cover loss. Critically, we found both large differences in range sizes and low range overlap between our range polygons and expert-drawn maps. Our threat exposure metric revealed high threat levels and increased risk for several shieldtail species. Overall, we demonstrate the utility of citizen science projects in effectively gathering distribution data on rare taxa and provide a framework for data-driven approaches to assess species threats.
Habitat selection by reintroduced and remnant populations of wood bison (Bison bison athabascae) in the boreal forest are not well understood, especially in landscapes characterized by anthropogenic disturbance. Yet, this information is key for conservation planning for wood bison, a threatened species in Canada. We used data from GPS-collared bison in northeastern British Columbia to develop seasonal resource selection function models that quantified selection or avoidance of oil and gas infrastructure, as well as natural disturbances and other ecological factors. We predicted that bison would select a range of early seral habitat types including areas associated with linear features and industrial activities. Consistent with our predictions, resource roads were the most influential disturbance features associated with resource selection of GPS-collared bison during winter and summer. Across both seasons, bison selected for areas close to most linear disturbance features but avoided areas with relatively greater densities of linear disturbances. Bison may use linear disturbances as travel corridors or as foraging habitat, but there appears to be a threshold above which bison avoid these features. Conversely, bison selected areas closer to polygonal disturbances (e.g., well sites) in both seasons and selected areas with greater densities of these features in the winter. Overall, we found that bison selected for anthropogenic features associated with the oil and gas industry. Although these recently disturbed vegetation communities provide foraging habitat, they also lead to conflict with humans that may result in the mortality of bison. Mitigations such as restoring disturbed habitats to a natural state, management actions that discourage or prevent the use of anthropogenic habitats, and fostering a stewardship ethic within industry will improve human-bison coexistence on landscapes characterized by anthropogenic disturbance.
