Savanna resilience to droughts increases with the proportion of browsing wild herbivores and plant functional diversity

1. Maintaining the resilience and functionality of savannas is key to sustaining the ecosystem services they provide. This maintenance is largely dependent on the resilience of savannas to stressors, such as prolonged droughts. The resilience to drought is largely determined by the interaction of herbivores and the functional composition of vegetation. So far, our understanding and ability to predict the response of savannas to drought under different types of rangeland use and as a function of vegetation composition are still limited. 2. In this study, we used the ecohydrological, spatially-explicit savanna model EcoHyD to determine if the resilience of a savanna rangeland towards prolonged droughts can be enhanced by the choice of rangeland use type (grazer-dominated, mixed-feeders or browser-dominated) and animal density. We evaluated the ability of a Namibian savanna system to withstand droughts and recover from droughts based on its perennial grass cover and the overall species composition. 3. Generally, we determined a low resilience under high grazer densities. Most importantly, we found that functional diversification of herbivores and plants acted as resilience insurance against droughts, leading to greater resistance and recovery of perennial grasses. In particular, a higher proportion of herbivores allowed for higher resilience, probably also due to a short-term switch to more drought-resistant or unpalatable species. 4. In this case, herbivore diversification was of high self-regulatory value by reestablishing trophic complexity, reducing the need for additional management interventions. 5. Synthesis and applications: Savanna systems will be more resistant to drought if (i) a dense perennial grass cover is maintained, protecting the topsoil from heat-induced water losses and erosion, encompassing functionally important species that are particularly well adapted to water stress and that are palatable, if (ii) the grazing pressure is adjusted to the productivity of the system, and (iii) the herbivore community includes browsers

Leopard Panthera pardus camera trap surveys in the arid environments of northern Namibia

In Namibia, leopards (Panthera pardus) are widely distributed, used commercially as trophy animals and are often persecuted for perceived or real predation on livestock and valuable game species outside protected areas. Therefore, leopard populations living in protected areas might be important source populations and for maintaining connectivity. Little data on their population sizes and densities are available from the northern part of the country, particularly from protected areas. Here, we estimated leopard densities using a spatial capture–recapture approach in northern Namibia: (i) the Khaudum National Park (KNP) in north-east Namibia with an annual average rainfall of 450 mm and (ii) the Lower Hoanib River (LHR) in north-west Namibia with an annual average rainfall of 25 mm. With an effort of 2430 and 2074 camera trap nights in the KNP and LHR, respectively, 11 adult female and six adult male leopards were identified in the KNP, whilst only one adult female leopard was detected once in the LHR. For the KNP, a maximum likelihood approach (using the package SECR) revealed a density estimate of 2.74 leopards/100 km2, whereas a Bayesian approach (using the package SPACECAP) revealed a density estimate of 1.83 leopards/100 km2. For the LHR, no density estimate could be determined and it is suggested that the leopard density in such an arid environment is low. These are the first leopard density estimates based on camera trap surveys provided for these protected areas and thus of importance for further monitoring programs to understand leopard population dynamics. We discuss our findings with current habitat changes and conservation measures in both study areas.Open Access funding enabled and organized by Projekt DEAL. The publication of this article was funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) – project number 491292795. This study was funded by the Ministry of Environment, Forestry and Tourism (MEFT) in Namibia, WWF Germany and the Messerli Foundation in Switzerland. Sarah Edwards received a post-doctoral bursary from the University of Pretoria, South Africa.https://link.springer.com/journal/42991hj2023Centre for Wildlife Managemen

Making the most of by-catch data : assessing the feasibility of utilising non-target camera trap data for occupancy modelling of a large felid

Camera traps are an increasingly used tool in ecology, having the ability to capture large numbers of photographic records in short survey periods. For many surveys, the number of non‐target records outweighs those of focal species, making them a potentially rich and often under‐utilised data source. Occupancy analysis of non‐target data represents a potential way to optimise survey output, whilst increasing “return on investment.” This study assessed the feasibility of using non‐target data from a Hartmann's mountain zebra Equus zebra hartmannae survey in Gondwana Canyon Park, southern Namibia, for occupancy analysis on leopard Panthera pardus. Using a survey design with 15 camera traps at water sources, 26 leopard events were detected over 72 days. Model fit was adequate and produced a model‐averaged occupancy of 0.64 (SE 0.36) and a detection probability of 0.24 (SE 0.07). Whilst there was a lack of precision in the final occupancy estimate, the study provided valuable pilot data for future surveys. The results highlight the ability of camera traps to obtain information‐rich datasets, which, when properly archived, can be used for providing information on a number of ecological topics, ranging far beyond that which the traps were originally deployed for.The Rufford Foundation, United Kingdom, the Whitley Fund for Nature, United Kingdom, and Parc Zoologique de Montpellier, France, funded the Mountain Zebra Project. Sarah Edwards received a post‐doctoral bursary from the University of Pretoria, South Africa.http://wileyonlinelibrary.com/journal/aje2019-12-01hj2018Centre for Wildlife Managemen

Behavioral responses of terrestrial mammals to COVID-19 lockdowns

COVID-19 lockdowns in early 2020 reduced human mobility, providing an opportunity to disentangle its effects on animals from those of landscape modifications. Using GPS data, we compared movements and road avoidance of 2300 terrestrial mammals (43 species) during the lockdowns to the same period in 2019. Individual responses were variable with no change in average movements or road avoidance behavior, likely due to variable lockdown conditions. However, under strict lockdowns 10-day 95th percentile displacements increased by 73%, suggesting increased landscape permeability. Animals' 1-hour 95th percentile displacements declined by 12% and animals were 36% closer to roads in areas of high human footprint, indicating reduced avoidance during lockdowns. Overall, lockdowns rapidly altered some spatial behaviors, highlighting variable but substantial impacts of human mobility on wildlife worldwide.acceptedVersio

Guidelines for evaluating the conservation value of African lion (Panthera leo) translocations

As the top predator in African ecosystems, lions have lost more than 90% of their historical range, and few countries possess strong evidence for stable populations. Translocations (broadly defined here as the capture and movement of lions for various management purposes) have become an increasingly popular action for this species, but the wide array of lion translocation rationales and subsequent conservation challenges stemming from poorly conceived or unsuitable translocations warrants additional standardized evaluation and guidance. At their best, translocations fill a key role in comprehensive strategies aimed at addressing the threats facing lions and fostering the recovery of wild populations in their historic range. At their worst, translocations can distract from addressing the major threats to wild populations and habitats, divert scarce funding from more valuable conservation actions, exacerbate conflict with humans in recipient sites, disrupt local lion demography, and undermine the genetic integrity of wild lion populations in both source and recipient sites. In the interest of developing best practice guidelines for deciding when and how to conduct lion translocations, we discuss factors to consider when determining whether a translocation is of conservation value, introduce a value assessment for translocations, and provide a decision matrix to assist practitioners in improving the positive and reducing the negative outcomes of lion translocation.Grant from the European Union through IUCN Save Our Species, and the United States Fish and Wildlife Service.https://www.frontiersin.org/journals/conservation-scienceam2023Zoology and Entomolog

Behavioral responses of terrestrial mammals to COVID-19 lockdowns

DATA AND MATERIALS AVAILABILITY : The full dataset used in the final analyses (33) and associated code (34) are available at Dryad. A subset of the spatial coordinate datasets is available at Zenodo (35). Certain datasets of spatial coordinates will be available only through requests made to the authors due to conservation and Indigenous sovereignty concerns (see table S1 for more information on data use restrictions and contact information for data requests). These sensitive data will be made available upon request to qualified researchers for research purposes, provided that the data use will not threaten the study populations, such as by distribution or publication of the coordinates or detailed maps. Some datasets, such as those overseen by government agencies, have additional legal restrictions on data sharing, and researchers may need to formally apply for data access. Collaborations with data holders are generally encouraged, and in cases where data are held by Indigenous groups or institutions from regions that are under-represented in the global science community, collaboration may be required to ensure inclusion.COVID-19 lockdowns in early 2020 reduced human mobility, providing an opportunity to disentangle its effects on animals from those of landscape modifications. Using GPS data, we compared movements and road avoidance of 2300 terrestrial mammals (43 species) during the lockdowns to the same period in 2019. Individual responses were variable with no change in average movements or road avoidance behavior, likely due to variable lockdown conditions. However, under strict lockdowns 10-day 95th percentile displacements increased by 73%, suggesting increased landscape permeability. Animals’ 1-hour 95th percentile displacements declined by 12% and animals were 36% closer to roads in areas of high human footprint, indicating reduced avoidance during lockdowns. Overall, lockdowns rapidly altered some spatial behaviors, highlighting variable but substantial impacts of human mobility on wildlife worldwide.The Radboud Excellence Initiative, the German Federal Ministry of Education and Research, the National Science Foundation, Serbian Ministry of Education, Science and Technological Development, Dutch Research Council NWO program “Advanced Instrumentation for Wildlife Protection”, Fondation Segré, RZSS, IPE, Greensboro Science Center, Houston Zoo, Jacksonville Zoo and Gardens, Nashville Zoo, Naples Zoo, Reid Park Zoo, Miller Park, WWF, ZCOG, Zoo Miami, Zoo Miami Foundation, Beauval Nature, Greenville Zoo, Riverbanks zoo and garden, SAC Zoo, La Passarelle Conservation, Parc Animalier d’Auvergne, Disney Conservation Fund, Fresno Chaffee zoo, Play for nature, North Florida Wildlife Center, Abilene Zoo, a Liber Ero Fellowship, the Fish and Wildlife Compensation Program, Habitat Conservation Trust Foundation, Teck Coal, and the Grand Teton Association. The collection of Norwegian moose data was funded by the Norwegian Environment Agency, the German Ministry of Education and Research via the SPACES II project ORYCS, the Wyoming Game and Fish Department, Wyoming Game and Fish Commission, Bureau of Land Management, Muley Fanatic Foundation (including Southwest, Kemmerer, Upper Green, and Blue Ridge Chapters), Boone and Crockett Club, Wyoming Wildlife and Natural Resources Trust, Knobloch Family Foundation, Wyoming Animal Damage Management Board, Wyoming Governor’s Big Game License Coalition, Bowhunters of Wyoming, Wyoming Outfitters and Guides Association, Pope and Young Club, US Forest Service, US Fish and Wildlife Service, the Rocky Mountain Elk Foundation, Wyoming Wild Sheep Foundation, Wild Sheep Foundation, Wyoming Wildlife/Livestock Disease Research Partnership, the US National Science Foundation [IOS-1656642 and IOS-1656527, the Spanish Ministry of Economy, Industry and Competitiveness, and by a GRUPIN research grant from the Regional Government of Asturias, Sigrid Rausing Trust, Batubay Özkan, Barbara Watkins, NSERC Discovery Grant, the Federal Aid in Wildlife Restoration act under Pittman-Robertson project, the State University of New York, College of Environmental Science and Forestry, the Ministry of Education, Youth and Sport of the Czech Republic, the Ministry of Agriculture of the Czech Republic, Rufford Foundation, an American Society of Mammalogists African Graduate Student Research Fund, the German Science Foundation, the Israeli Science Foundation, the BSF-NSF, the Ministry of Agriculture, Forestry and Food and Slovenian Research Agency (CRP V1-1626), the Aage V. Jensen Naturfond (project: Kronvildt - viden, værdier og værktøjer), the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany’s Excellence Strategy, National Centre for Research and Development in Poland, the Slovenian Research Agency, the David Shepherd Wildlife Foundation, Disney Conservation Fund, Whitley Fund for Nature, Acton Family Giving, Zoo Basel, Columbus, Bioparc de Doué-la-Fontaine, Zoo Dresden, Zoo Idaho, Kolmården Zoo, Korkeasaari Zoo, La Passarelle, Zoo New England, Tierpark Berlin, Tulsa Zoo, the Ministry of Environment and Tourism, Government of Mongolia, the Mongolian Academy of Sciences, the Federal Aid in Wildlife Restoration act and the Illinois Department of Natural Resources, the National Science Foundation, Parks Canada, Natural Sciences and Engineering Research Council, Alberta Environment and Parks, Rocky Mountain Elk Foundation, Safari Club International and Alberta Conservation Association, the Consejo Nacional de Ciencias y Tecnología (CONACYT) of Paraguay, the Norwegian Environment Agency and the Swedish Environmental Protection Agency, EU funded Interreg SI-HR 410 Carnivora Dinarica project, Paklenica and Plitvice Lakes National Parks, UK Wolf Conservation Trust, EURONATUR and Bernd Thies Foundation, the Messerli Foundation in Switzerland and WWF Germany, the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie Actions, NASA Ecological Forecasting Program, the Ecotone Telemetry company, the French National Research Agency, LANDTHIRST, grant REPOS awarded by the i-Site MUSE thanks to the “Investissements d’avenir” program, the ANR Mov-It project, the USDA Hatch Act Formula Funding, the Fondation Segre and North American and European Zoos listed at http://www.giantanteater.org/, the Utah Division of Wildlife Resources, the Yellowstone Forever and the National Park Service, Missouri Department of Conservation, Federal Aid in Wildlife Restoration Grant, and State University of New York, various donors to the Botswana Predator Conservation Program, data from collared caribou in the Northwest Territories were made available through funds from the Department of Environment and Natural Resources, Government of the Northwest Territories. The European Research Council Horizon2020, the British Ecological Society, the Paul Jones Family Trust, and the Lord Kelvin Adam Smith fund, the Tanzania Wildlife Research Institute and Tanzania National Parks. The Eastern Shoshone and Northern Arapahoe Fish and Game Department and the Wyoming State Veterinary Laboratory, the Alaska Department of Fish and Game, Kodiak Brown Bear Trust, Rocky Mountain Elk Foundation, Koniag Native Corporation, Old Harbor Native Corporation, Afognak Native Corporation, Ouzinkie Native Corporation, Natives of Kodiak Native Corporation and the State University of New York, College of Environmental Science and Forestry, and the Slovenia Hunters Association and Slovenia Forest Service. F.C. was partly supported by the Resident Visiting Researcher Fellowship, IMéRA/Aix-Marseille Université, Marseille. This work was partially funded by the Center of Advanced Systems Understanding (CASUS), which is financed by Germany’s Federal Ministry of Education and Research (BMBF) and by the Saxon Ministry for Science, Culture and Tourism (SMWK) with tax funds on the basis of the budget approved by the Saxon State Parliament. This article is a contribution of the COVID-19 Bio-Logging Initiative, which is funded in part by the Gordon and Betty Moore Foundation (GBMF9881) and the National Geographic Society.https://www.science.org/journal/sciencehj2023Mammal Research InstituteZoology and Entomolog

Leopard Panthera pardus camera trap surveys in the arid environments of northern Namibia

In Namibia, leopards (Panthera pardus) are widely distributed, used commercially as trophy animals and are often persecuted for perceived or real predation on livestock and valuable game species outside protected areas. Therefore, leopard populations living in protected areas might be important source populations and for maintaining connectivity. Little data on their population sizes and densities are available from the northern part of the country, particularly from protected areas. Here, we estimated leopard densities using a spatial capture–recapture approach in northern Namibia: (i) the Khaudum National Park (KNP) in north-east Namibia with an annual average rainfall of 450 mm and (ii) the Lower Hoanib River (LHR) in north-west Namibia with an annual average rainfall of 25 mm. With an effort of 2430 and 2074 camera trap nights in the KNP and LHR, respectively, 11 adult female and six adult male leopards were identified in the KNP, whilst only one adult female leopard was detected once in the LHR. For the KNP, a maximum likelihood approach (using the package SECR) revealed a density estimate of 2.74 leopards/100 km2, whereas a Bayesian approach (using the package SPACECAP) revealed a density estimate of 1.83 leopards/100 km2. For the LHR, no density estimate could be determined and it is suggested that the leopard density in such an arid environment is low. These are the first leopard density estimates based on camera trap surveys provided for these protected areas and thus of importance for further monitoring programs to understand leopard population dynamics. We discuss our findings with current habitat changes and conservation measures in both study areas

Being stressed outside the park — conservation of African elephants (Loxodonta africana) in Namibia

The conservation of the African savanna elephant (Loxodonta africana) is of prime importance for many African countries. Interactions between elephants and humans are known to induce stress and thereby have the potential to affect elephants’fitness. In Namibia, anthropogenic disturbances are increasing due to increasing human population size and development, particularly near protected areas, such as national parks. In this study, we investigated elephant stress levels in relation to their land use, specifically their protection status, comparing elephants within Etosha National Park in Namibia with elephants residing outside the park. We noninvasively collected dung samples of 91 elephants and determined the concentration of faecal glucocorticoid metabolites (fGCM), an indicator of physiological stress. Elephants outside the park (N = 35) had significantly higher concentrations of fGCM than those inside ENP (N = 56), suggesting that, despite including community-based conservancies, unprotected areas are more stressful for elephants than protected areas, most likely due to increased interactions with humans. We also found that males had lower fGCM concentrations than females, but no significant effect of age, body size or group size was detected. Additionally, herd sizes were significantly smaller and calf recruitment was potentially lower in unprotected areas. These findings underpin the importance of protected areas such as ENP, while encouraging decision-makers to continue reducing and mitigating potential human-induced disturbances.publishedVersio