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The broad negative effects of land-use conversion for agriculture on wildlife species are well known, but few studies have evaluated how different land-use types impact spatiotemporal patterns and trophic strategy of large carnivores. We conducted sign surveys for the Asiatic black bear, a critically endangered subspecies in southeastern Iran. We applied Bayesian occupancy modelling and quantified spatiotemporal determinants of black bear occurrence as a function of date palms, distance to agriculture, elevation, precipitation, and protected area (PA) size. We also investigated its diet composition based on scat (n = 150) analyses. Date palm area size (β = 2.07; 95 % Credible Interval = 0.67 to 3.89) and distance to croplands had a strong and significant (β = −1.06, 95 % CrI = −2.10 to −0.20) influence on the occupancy. Elevation, precipitation, village density, and PA size did not substantially influence occupancy. Black bear detection probability became 100 % only above 14 km survey effort, indicating its overall rarity, and bears were much more easily detected during and after rainfall. Bears mainly relied on date palms (41 %) followed by herbaceous plants (24.6 %), insects (15 %), wild mammals (6.4 %), wild fruits (5.6 %), livestock (4.9 %) and other vertebrates (2.5 %, e.g., birds). Most of the predicted bear occupancy was outside PAs and thus suggests a high likelihood of human-bear conflicts. Presumably, resource density is insufficient to support bears inside PAs, but information concerning resource density is currently lacking. Our results showed that the agricultural landscape provided an important feeding (46 %) area for bears. Consequently, effective conservation programs such as the protection of abandoned date palm groves as a conflict-free food source are necessary. Practical training such as protective measures against crop-raiding behavior of bears would be essential to foster the tolerance of people toward bears and thus can help facilitate coexistence.

Abstract Background Northern ecosystems are strongly influenced by herbivores that differ in their impacts on the ecosystem. Yet the role of herbivore diversity in shaping the structure and functioning of tundra ecosystems has been overlooked. With climate and land-use changes causing rapid shifts in Arctic species assemblages, a better understanding of the consequences of herbivore diversity changes for tundra ecosystem functioning is urgently needed. This systematic review synthesizes available evidence on the effects of herbivore diversity on different processes, functions, and properties of tundra ecosystems. Methods Following a published protocol, our systematic review combined primary field studies retrieved from bibliographic databases, search engines and specialist websites that compared tundra ecosystem responses to different levels of vertebrate and invertebrate herbivore diversity. We used the number of functional groups of herbivores (i.e., functional group richness) as a measure of the diversity of the herbivore assemblage. We screened titles, abstracts, and full texts of studies using pre-defined eligibility criteria. We critically appraised the validity of the studies, tested the influence of different moderators, and conducted sensitivity analyses. Quantitative synthesis (i.e., calculation of effect sizes) was performed for ecosystem responses reported by at least five articles and meta-regressions including the effects of potential modifiers for those reported by at least 10 articles. Review findings The literature searches retrieved 5944 articles. After screening titles, abstracts, and full texts, 201 articles including 3713 studies (i.e., individual comparisons) were deemed relevant for the systematic review, with 2844 of these studies included in quantitative syntheses. The available evidence base on the effects of herbivore diversity on tundra ecosystems is concentrated around well-established research locations and focuses mainly on the impacts of vertebrate herbivores on vegetation. Overall, greater herbivore diversity led to increased abundance of feeding marks by herbivores and soil temperature, and to reduced total abundance of plants, graminoids, forbs, and litter, plant leaf size, plant height, and moss depth, but the effects of herbivore diversity were difficult to tease apart from those of excluding vertebrate herbivores. The effects of different functional groups of herbivores on graminoid and lichen abundance compensated each other, leading to no net effects when herbivore effects were combined. In turn, smaller herbivores and large-bodied herbivores only reduced plant height when occurring together but not when occurring separately. Greater herbivore diversity increased plant diversity in graminoid tundra but not in other habitat types. Conclusions This systematic review underscores the importance of herbivore diversity in shaping the structure and function of Arctic ecosystems, with different functional groups of herbivores exerting additive or compensatory effects that can be modulated by environmental conditions. Still, many challenges remain to fully understand the complex impacts of herbivore diversity on tundra ecosystems. Future studies should explicitly address the role of herbivore diversity beyond presence-absence, targeting a broader range of ecosystem responses and explicitly including invertebrate herbivores. A better understanding of the role of herbivore diversity will enhance our ability to predict whether and where shifts in herbivore assemblages might mitigate or further amplify the impacts of environmental change on Arctic ecosystems.

Abstract Anthropogenic eutrophication of ecosystems is an important driver of biodiversity loss. Even protected areas (PAs) may be impacted by anthropogenic nutrients, for example, from atmospheric deposition or the provision of supplementary feeding. However, the resultant nutrient patterns, and the role of local wildlife in shaping them, remain poorly understood. We investigated anthropogenic influences on the role that red deer (Cervus elaphus) play in the nutrient balance of a PA in Denmark. We used habitat selection modeling and theoretical scenarios where we varied the proportion of energy the deer obtained from supplementary versus natural forage and compared it with the nutrients removed due to hunting. We show that the movement and distribution of the red deer population within the PA are very heterogeneous and likely influenced by the need for shelter. Moreover, depending on their reliance on supplementary feeding, deer can potentially import large amounts of nutrients to the PA, and concentrate them in localized hotspots. However, we also explore the potential for nutrient loss due to hunting activities. Such indirect anthropogenic impacts on nutrient landscapes may counteract restoration and conservation efforts. We therefore recommend incorporating anthropogenic influences on zoogeochemistry and the animal‐mediated connectivity between PAs and anthropogenically dominated landscapes into future management plans.