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ContextMany large carnivores depend on habitat patches outside protected areas, as well as safe corridors between them. However, corridor assessments typically ignore potential conflicts between carnivores and people, which can undermine corridor effectiveness and thus conservation success.ObjectivesWe identified safe dispersal corridors and conflict-prone movement bottlenecks for Persian leopard (Panthera pardus saxicolor) between protected areas in the Alborz Mountains, Iran, by mapping habitat, landscape permeability, and conflict risk. We then identified priority areas for conservation interventions according to the intensities of different threats.MethodsWe mapped land cover using Landsat satellite images, gathered data on leopard and prey distributions and livestock depredation events via interview surveys in 69 cells of 6 × 6 km each. We then used occupancy modeling to identify habitat patches, used circuit theory modeling to analyze landscape permeability, and assessed human-leopard conflict risk using generalized linear models.ResultsLeopard habitat use increased with prey availability and decreased with elevation. Prey distribution, in turn, was mostly negatively influenced by agricultural lands and distance from protected areas. Conflict risk (i.e., probability of leopard depredation on livestock) was high in landscapes where agriculture was widespread and historical forest loss high. Not accounting for conflicts overestimated connectivity among habitat patches substantially.ConclusionsHuman-carnivore conflicts are an important constraint to connectivity and should be considered in corridor assessments. Our study shows how habitat analysis, connectivity assessment, and conflict risk mapping can be combined to guide conservation planning for identifying habitat networks and safe corridors for carnivores in human-dominated landscapes.

Climate change disproportionately threatens alpine species, by reducing available habitat and by isolating their populations. These pressures are particularly relevant for rear‐edge populations, which typically occupy more marginal habitat compared to populations at the core of species' ranges. We studied Caucasian grouse Lyrurus mlokosiewiczi in the Caucasus ecoregion, a global biodiversity hotspot where this species is endemic, to understand potential climate change impacts on the species. Specifically, we assessed how climate change impacts rear‐edge populations and how important these populations are for understanding range shifts and adaptive capacity under climate change. We used maximum entropy modeling to assess changes in the distribution of climatically suitable habitat under present and 2070 climate conditions for the representative concentration pathways 8.5 (RCP8.5). Our results revealed that ignoring rear‐edge populations leads to a significant underestimation of the future range (by about 14,700 km2). Rear‐edge populations were better adapted to warmer climates compared to core populations, and ignoring them, therefore, also underestimates adaptive capacity. Preventing the loss of rear‐edge populations should, therefore, be a priority for conservation planning in the face of climate change. Because the Caucasian grouse is associated with alpine mountain tops, conservation should focus on establishing connectivity between rear‐edge and core populations (e.g., via transboundary corridors or assisted colonizations). Our study reveals how species distribution modeling can highlight the importance of rear‐edge populations for mitigating climate change impacts on species of conservation concern.

Mountain ungulates around the world have been decimated to small, fragmented populations. Restoring these species often is limited by inadequate information on where suitable habitat is found, and which restoration measures would help to increase and link existing populations. We developed an approach to spatially target threat‐specific restoration actions and demonstrate it for bezoar goats (Capra aegagrus) in the Caucasus. Using a large occurrence dataset, we identified suitable habitat patches and evaluate them in terms of connectivity, protection status, and competition with other mountain ungulates. We found extant bezoar goat populations to be highly isolated, yet with widespread areas of suitable, unoccupied habitat between them. Many unoccupied habitat patches were well‐connected to extant populations, were at least partly protected, and have low potential for competition with other Capra species. This signals substantial pressure on bezoar goats, likely due to poaching, which currently prevents natural recolonization. Our study shows how restoration planning is possible in the face of multiple threats and scarce data. For bezoar goats in the Caucasus, we pinpoint priority patches for specific restoration measures, including reintroductions and anti‐poaching action. We highlight that many patches would benefit from multiple interventions and that transboundary restoration planning is needed, a situation likely similar for many mountain ungulates around the world.

ContextUnderstanding habitat selection can be challenging for species surviving in small populations, but is needed for landscape-scale conservation planning.ObjectivesWe assessed how European bison (Bison bonasus) habitat selection, and particularly forest use, varies across subpopulations and spatial scales.MethodsWe gathered the most comprehensive European bison occurrence dataset to date, from five free-ranging herds in Poland. We compared these data to a high-resolution forest map and modelled the influence of environmental and human-pressure variables on habitat selection.ResultsAround 65% of European bison occurrences were in forests, with cows showing a slightly higher forest association than bulls. Forest association did not change markedly across spatial scales, yet differed strongly among herds. Modelling European bison habitat suitability confirmed forest preference, but also showed strong differences in habitat selection among herds. Some herds used open areas heavily and actively selected for them. Similarly, human-pressure variables were important in all herds, but some herds avoided human-dominated areas more than others.ConclusionsAssessing European bison habitat across multiple herds revealed a more generalist habitat use pattern than when studying individual herds only. Our results highlight that conflicts with land use and people could be substantial if bison are released in human-dominated landscapes. Future restoration efforts should target areas with low road and human population density, regardless of the degree of forest cover. More broadly, our study highlights the importance of considering multiple subpopulations and spatial scales in conservation planning.

Large carnivores are currently disappearing from many world regions because of habitat loss, prey depletion, and persecution. Ensuring large carnivore persistence requires safeguarding and sometimes facilitating the expansion of their populations. Understanding which conservation strategies, such as reducing persecution or restoring prey, are most effective to help carnivores to reclaim their former ranges is therefore important. Here, we systematically explored such alternative strategies for the endangered Persian leopard (Panthera pardus saxicolor) in the Caucasus. We combined a rule-based habitat suitability map and a spatially explicit leopard population model to identify potential leopard subpopulations (i.e., breeding patches), and to test the effect of different levels of persecution reduction and prey restoration on leopard population viability across the entire Caucasus ecoregion and northern Iran (about 737,000 km²). We identified substantial areas of potentially suitable leopard habitat (~120,000 km²), most of which is currently unoccupied. Our model revealed that leopards could potentially recolonize these patches and increase to a population of >1,000 individuals in 100 yr, but only in scenarios of medium to high persecution reduction and prey restoration. Overall, reducing persecution had a more pronounced effect on leopard metapopulation viability than prey restoration: Without conservation strategies to reduce persecution, leopards went extinct from the Caucasus in all scenarios tested. Our study highlights the importance of persecution reduction in small populations, which should hence be prioritized when resources for conservation are limited. We show how individual-based, spatially explicit metapopulation models can help in quantifying the recolonization potential of large carnivores in unoccupied habitat, designing adequate conservation strategies to foster such recolonizations, and anticipating the long-term prospects of carnivore populations under alternative scenarios. Our study also outlines how data scarcity, which is typical for threatened range-expanding species, can be overcome with a rule-based habitat map. For Persian leopards, our projections clearly suggest that there is a large potential for a viable metapopulation in the Caucasus, but only if major conservation actions are taken towards reducing persecution and restoring prey.

Poaching is driving many species toward extinction, and as a result, lowering poaching pressure is a conservation priority. This requires understanding where poaching pressure is high and which factors determine these spatial patterns. However, the cryptic and illegal nature of poaching makes this difficult. Ranger patrol data, typically recorded in protected area logbooks, contain information on patrolling efforts and poaching detection and should thus provide opportunities for a better understanding of poaching pressure. However, these data are seldom analyzed and rarely used to inform adaptive management strategies. We developed a novel approach to making use of analog logbook records to map poaching pressure and to test environmental criminology and predator–prey relationship hypotheses explaining poaching patterns. We showcase this approach for Golestan National Park in Iran, where poaching has substantially depleted ungulate populations. We digitized data from >4800 ranger patrols from 2014 to 2016 and used an occupancy modeling framework to relate poaching to (1) accessibility, (2) law enforcement, and (3) prey availability factors. Based on predicted poaching pressure and patrolling intensity, we provide suggestions for future patrol allocation strategies. Our results revealed a low probability (12%) of poacher detection during patrols. Poaching distribution was best explained by prey availability, indicating that poachers target areas with high concentrations of ungulates. Poaching pressure was estimated to be high (>0.49) in 39% of our study area. To alleviate poaching pressure, we recommend ramping up patrolling intensity in 12% of the national park, which could be achievable by reducing excess patrols in about 20% of the park. However, our results suggest that for 27% of the park, it is necessary to improve patrolling quality to increase detection probability of poaching, for example, by closing temporal patrolling gaps or expanding informant networks. Our approach illustrates that analog ranger logbooks are an untapped resource for evidence-based and adaptive planning of protected area management. Using this wealth of data can open up new avenues to better understand poaching and its determinants, to expand effectiveness assessments to the past, and, more generally, to allow for strategic conservation planning in protected areas.

Aim: Large and ecologically functioning steppe complexes have been lost historically across the globe, but recent land-use changes may allow the reversal of this trend in some regions. We aimed to develop and map indicators of changing human influence using satellite imagery and historical maps, and to use these indicators to identify areas for broad-scale steppe rewilding. Location: Eurasian steppes of Kazakhstan. Methods: We mapped decreasing human influence indicated by cropland abandonment, declining grazing pressure and rural outmigration in the steppes of northern Kazakhstan. We did this by processing  5,500 Landsat scenes to map changes in cropland between 1990 and 2015, and by digitizing Soviet topographic maps and examining recent high-resolution satellite imagery to assess the degree of abandonment of >2,000 settlements and >1,300 livestock stations. We combined this information into a human influence index (HI), mapped changes in HI to highlight where rewilding might take place and assessed how this affected the connectivity of steppe habitat. Results: Across our study area, about 6.2 million ha of cropland were abandoned (30.5\\%), 14\\% of all settlements were fully and 81\\% partly abandoned, and 76\\% of livestock stations were completely dismantled between 1990 and 2015, suggesting substantially decreasing human pressure across vast areas. This resulted in increased connectivity of steppe habitat. Main conclusions: The steppes of Eurasia are experiencing massively declining human influence, suggesting large-scale passive rewilding is taking place. Many of these areas are now important for the connectivity of the wider steppe landscape and can provide habitat for endangered megafauna such as the critically endangered saiga antelope. Yet, this window of opportunity may soon close, as recultivation of abandoned cropland is gaining momentum. Our aggregate human influence index captures key components of rewilding and can help to devise strategies for fostering large, connected networks of protected areas in the steppe.

International audience

Aim We investigated the effects of habitat destruction and hunting on the functional decline of top predators, specifically jaguar and puma, in the Gran Chaco. Location The 1.1 million km2 South American Gran Chaco. Methods We used spatially explicit, individual‐based models for jaguars and pumas, incorporating detailed information on habitat suitability and hunting pressure. We parameterized our models with literature data and calibrated them through a Delphi expert‐elicitation process. We simulated population trajectories under a hypothetical, threat‐free, baseline versus different threat scenarios. Results Under combined threats of hunting and habitat loss, jaguar and puma populations declined by 88% and 80%, respectively, compared to range contractions of 48% and 35%, respectively. Both species remained regionally viable, particularly due to large protected areas, which acted as population sources but were surrounded by strong sinks. We observed a widespread weakening of the top carnivore guild function, with at least one species extirpated across 67% of the Chaco and strong declines (> 80%; considered here as functional loss) for both species concurrently across 61% of their area of historical co‐occurrence. Hunting was a much stronger driver of population declines (88% and 77% for jaguars and pumas, respectively) compared to habitat destruction (26% and 22%). Main Conclusions Large predators play key functional roles in ecosystems. Our findings reveal that these functions can be lost over vast areas due to the combined effects of habitat destruction and hunting, with functional loss extending far beyond the areas of species' extirpation. Very large protected areas, like Kaa‐Iya in Bolivia, are crucial for maintaining viable populations of top predators, highlighting the pressing need for increased protection and connectivity in the Chaco to prevent further trophic downgrading. More generally, our research underscores the value of spatially detailed, mechanistic models for disentangling the complex dynamics of multiple threats on ecological functioning at broad scales.

Aim Populations of large ungulates are dwindling worldwide. This is especially so for wild sheep, which compete with livestock for forage, are disturbed by shepherds and their dogs, and are exposed to disease transmissions from livestock. Our aim was to assess spatial patterns in realized niche overlap between wild and domestic sheep to better understand where potential competition might arise, and thus to identify priority areas for wild sheep recovery. Location Southern Caucasus (220,000 km2). Methods We studied Gmelin's mouflon (Ovis orientalis gmelinii), an ancestor of domestic sheep, to investigate seasonal habitat use and niche overlap with domestic sheep. To map habitat, we analysed mouflon occurrences collected during 2006–2016, and domestic sheep occurrences from shepherd camp locations digitized on high‐resolution satellite imagery. We mapped areas of potential competition between mouflon and domestic sheep and assessed potential habitat displacement. Results Mouflon and domestic sheep niches overlapped substantially (overlap index I = 0.89, where 1 means perfect overlap) but were not identical. Mouflon habitat was less widespread than domestic sheep habitat (14,000 vs. 40,270 km2) and tended to be located in more rugged areas with less vegetation cover. We identified 51 priority patches as reintroduction candidates if grazing pressure and poaching were reduced. Main conclusions Our results suggest that competition with domestic sheep might have pushed mouflon into marginal habitat. Thus, conservation efforts focusing on current mouflon habitat might miss suitable reintroduction sites. We demonstrate that a combined habitat model for wild and domestic sheep can identify general sheep habitat, which might be more useful for conservation planning than understanding current mouflon habitat selection. Our results highlight that considering competition with livestock is important for large ungulate conservation, both in terms of reactive (e.g., lessening livestock pressure in prime habitat) and proactive strategies (e.g., reintroduction in areas with low contemporary overlap).