Implementing a comprehensive approach to study the causes of human-bear (Ursus arctos pruinosus) conflicts in the Sanjiangyuan region, China

Human Expansion-Induced Biodiversity Crisis over Asia from 2000 to 2020

Asia stands out as a priority for urgent biodiversity conservation due to its large protected areas (PAs) and threatened species. Since the 21st century, both the highlands and lowlands of Asia have been experiencing the dramatic human expansion. However, the threat degree of human expansion to biodiversity is poorly understood. Here, the threat degree of human expansion to biodiversity over 2000 to 2020 in Asia at the continental (Asia), national (48 Asian countries), and hotspot (6,502 Asian terrestrial PAs established before 2000) scales is investigated by integrating multiple large-scale data. The results show that human expansion poses widespread threat to biodiversity in Asia, especially in Southeast Asia, with Malaysia, Cambodia, and Vietnam having the largest threat degrees (∼1.5 to 1.7 times of the Asian average level). Human expansion in highlands induces higher threats to biodiversity than that in lowlands in one-third Asian countries (most Southeast Asian countries). The regions with threats to biodiversity are present in ∼75% terrestrial PAs (including 4,866 PAs in 26 countries), and human expansion in PAs triggers higher threat degrees to biodiversity than that in non-PAs. Our findings provide novel insight for the Sustainable Development Goal 15 (SDG-15 Life on Land) and suggest that human expansion in Southeast Asian countries and PAs might hinder the realization of SDG-15. To reduce the threat degree, Asian developing countries should accelerate economic transformation, and the developed countries in the world should reduce the demands for commodity trade in Southeast Asian countries (i.e., trade leading to the loss of wildlife habitats) to alleviate human expansion, especially in PAs and highlands.

Food webs reveal coexistence mechanisms and community organization in carnivores

Globally, massive carnivore guild extirpations have led to trophic downgrading and compromised ecosystem services. However, the complexity of multi-carnivore food webs complicates accurate identification of species interactions and community organization. Here, we used fecal DNA metabarcoding to investigate three communities that together encompass eight large- and meso-carnivore species and their 44 prey taxa of the Qinghai-Tibet Plateau (QTP), one of the last places on Earth that still harbors intact carnivore assemblages. Quantitative food-web analyses revealed pronounced interspecific variations in the carnivores' prey compositions and dietary partitioning both between and within guilds. Additionally, body masses of the carnivores and their prey exhibited consistent hump-shaped correlations across communities. Overall, differences in prey diversity, size category, and proportional utilization among the carnivore species result in trophic niche segregation that likely promotes carnivore coexistence in the harsh QTP environment. Network structure analyses detected significant modularity in all food webs but nestedness in only one. Furthermore, network characterization identified pikas (Ochotona spp.), bharal (Pseudois nayaur), and domestic yak (Bos grunniens) as potential keystone prey across the areas. Our results paint a holistic and detailed picture of the QTP carnivore assemblages' trophic networks and demonstrate that the combined use of the molecular dietary approach and network analysis can generate structural insights into carnivore coexistence and can identify functionally important species in complex communities. Such knowledge can help safeguard carnivore guild integrity and enhance community resilience to environmental perturbations in the sensitive QTP ecosystems.

Activity patterns of Asiatic black bear (Ursus thibetanus) in the moist temperate forests of Machiara National Park, Azad Jammu and Kashmir, Pakistan

The Asiatic black bear (Ursus thibetanus) is an environmental indicator species whose activity patterns may be highly impacted by habitat changes. We monitored the monthly and daily activity patterns of black bears in the moist temperate forests of Machiara National Park. We used infrared camera traps and local ecological knowledge for data collection from April 2019 to April 2021. Camera traps recorded 109 [inside forest = 107, outside forest (near crop fields and human settlements) = 2] independent registrations (IR) in 5541 (692.63 ± 36.72, mean ± SD) camera days. We found (i) spring and autumn to be the lowest activity seasons for black bears inside the forest. (ii) The highest activity was recorded in summer, with a peak in August followed closely by July. (iii) The activity level sharply declined after August and halted from December to March, indicative of the bears' hibernation period. Local knowledge revealed that (i) bears remained active from May to November and hibernated the rest of the period. (ii) Bear activity was at its peak inside the forest in summer and outside the forest in autumn when bears sought to raid the widely cultivated maize crop (Zea mays) planted along forest edges. This increased activity outside of the forest is likely driven by decreased food availability inside the forest area and maize crop being a preferred anthropogenic food type for bears. Based on the daily activity pattern, bears exhibited cathemeral behavior (i.e., active throughout the day) with maximum overlap between camera trap and local ecological knowledge data. Human activity may be impacting the daily activity patterns of bears via disturbance and interference. The data collected in this study can help mitigate conflicts between humans and black bears and consequently assist in future conservation of black bears in the area.

Mitigation Strategies for Human-Tibetan Brown Bear (Ursus arctos pruinosus) Conflicts in the Hinterland of the Qinghai-Tibetan Plateau

Simple Summary

The conservation of Tibetan brown bear (Ursus arctos pruinosus) and its habitat is of great value to the conservation of sympatric species, which helps to maintain the health and stability of the regional ecosystem. In recent years, human–bear conflicts (HBCs) have intensified in the Sanjiangyuan Region in Qinghai Province, China, decreasing the tolerance of local herders of the species and seriously affecting the motivation of local communities to protect brown bears and other wildlife, with retaliatory killing posing a threat to their survival. Timely development of effective measures and countermeasures for mitigating HBCs is crucial to protect brown bears. The mitigation or resolution of HBC issues is beneficial to both the promotion of people’s livelihoods and the conservation of brown bears on the Qinghai-Tibetan Plateau (QTP). At present, there is still a lack of research on the mitigation measures of HBCs on the QTP. This study combined field surveys, semi-structured interviews, and HBC seminars to understand the effectiveness of current mitigation measures and to propose potential mitigation measures in the hinterland of the QTP. This work proposed targeted mitigation measures for HBCs taking into account existing HBC management practices in China and abroad, and the unique geographical environment, laws and regulations, folk culture, and religious beliefs of local regions. Although this study was limited to a single species on the QTP, the results herein are useful for drafting national-level wildlife conservation policies, compensation programs for wildlife damage, and natural resource conservation regulations.

Abstract

Personal injury and property damage caused by wildlife can worsen the relationship between humans and wildlife. In recent years, conflicts between herders and Tibetan brown bears (Ursus arctos pruinosus) (human–bear conflicts; HBCs) on the Qinghai-Tibetan Plateau have increased dramatically, severely affecting community motivation for the conservation of brown bears and other species. Understanding the types, effectiveness, and flaws of current HBC mitigation measures is critical to develop effective strategies to alleviate HBC. From 2017 to 2019, we conducted a systematic field survey regarding HBCs on the Qinghai-Tibetan Plateau. In addition, we invited bear specialists and multiple interest groups to hold an HBC seminar and proposed some potential mitigation strategies. We surveyed 312 families via semi-structured interviews and documented 16 types of HBC mitigation measures. A total of 96% of respondents were using more than two mitigation measures simultaneously. The effectiveness evaluation of HBC mitigation measures showed that: (1) removing food from winter homes while herders were at their summer pastures and asking people to keep watch of winter homes were effective at protecting food and houses; (2) traditional grazing methods (human guarding of livestock all day) and solar soundboxes (attached to livestock) were effective at protecting free-range livestock; (3) solar street lights had a deterrent effect on brown bears and were effective in protecting livestock, houses, and people; and (4) due to the unstable power supply of photovoltaic cells and improper installation of ground wires, electric fences were not ideal in practice. Evaluation of the potential mitigation measures at the seminar showed that upgrading electric fence technology, expanding electric fence pilot areas, installing diversionary feeders, and introducing bear spray were the most optimal solutions. This study provides a scientific basis for creating human–bear coexistence plans on the Qinghai-Tibet Plateau.