Differences in spatial niche of terrestrial mammals when facing extreme snowfall: the case in east Asian forests.

BACKGROUND: Recent climate changes have produced extreme climate events. This study focused on extreme snowfall and intended to discuss the vulnerability of temperate mammals against it through interspecies comparisons of spatial niches in northern Japan. We constructed niche models for seven non-hibernating species through wide-scaled snow tracking on skis, whose total survey length was 1144 km. RESULTS: We detected a low correlation (rs < 0.4) between most pairs of species niches, indicating that most species possessed different overwintering tactics. A morphological advantage in locomotion cost on snow did not always expand niche breadth. In contrast, a spatial niche could respond to (1) drastic landscape change by a diminishing understory due to snow, possibly leading to changes in predator-prey interactions, and (2) the mass of cold air, affecting thermoregulatory cost and food accessibility. When extraordinary snowfall occurred, the nonarboreal species with larger body sizes could niche shift, whereas the smaller-sized or semi-arboreal mammals did not. In addition, compared to omnivores, herbivores were prone to severe restriction of niche breadth due to a reduction in food accessibility under extreme climates. CONCLUSIONS: Dietary habits and body size could determine the redundancy of niche width, which may govern robustness/vulnerability to extreme snowfall events.

Bioacoustic monitoring to determine addiction levels of primates to the human sphere: A feasibility study on Japanese macaques.

Some nonhuman primate species, whose original habitats have been reclaimed by artificial activities, have acquired boldness toward humans which is evident based on the diminished frequency of escape behaviors. Eventually, such species have become regular users of human settlements, and are referred to as "urban primates." Considering this, we developed a noninvasive technique based on bioacoustics to provide a transparent assessment of troop addiction levels in anthropogenic environments, which are determined by the dependence on agricultural crops and human living sphere for their diets and daily ranging, respectively. We attempted to quantify the addiction levels based on the boldness of troops when raiding settlements, characterized by a "landscape of fear" because of the presence of humans as predators. We hypothesized that the boldness of troops could be measured using two indices: the frequency of raiding events on settlements and the amount of time spent there. For hypothesis testing, we devised an efficient method to measure these two indices using sound cues (i.e., spontaneous calls) for tracing troop movements that are obtainable throughout the day from most primate species (e.g., contact calls). We conducted a feasibility study of this assessment procedure, targeting troops of Japanese macaques (Macaca fuscata). For this study, we collected 346 recording weeks of data using autonomous recorders from 24 troops with different addiction levels during the nonsnowy seasons. The results demonstrated that troops that reached the threshold level, at which radical interventions including mass culling of troop members is officially permitted, could be readily identified based on the following behavioral characteristics: troop members raiding settlements two or three times per week and mean time spent in settlements per raiding event exceeding 0.4 h. Thus, bioacoustic monitoring could become a valid option to ensure the objectivity of policy judgment in urban primate management.

Diet-related factors strongly shaped the gut microbiota of Japanese macaques.

Although knowledge of the functions of the gut microbiome has increased greatly over the past few decades, our understanding of the mechanisms governing its ecology and evolution remains obscure. While host genetic distance is a strong predictor of the gut microbiome in large-scale studies and captive settings, its influence has not always been evident at finer taxonomic scales, especially when considering among the recently diverged animals in natural settings. Comparing the gut microbiome of 19 populations of Japanese macaques Macaca fuscata across the Japanese archipelago, we assessed the relative roles of host genetic distance, geographic distance and dietary factors in influencing the macaque gut microbiome. Our results suggested that the macaques may maintain a core gut microbiome, while each population may have acquired some microbes from its specific habitat/diet. Diet-related factors such as season, forest, and reliance on anthropogenic foods played a stronger role in shaping the macaque gut microbiome. Among closely related mammalian hosts, host genetics may have limited effects on the gut microbiome since the hosts generally have smaller physiological differences. This study contributes to our understanding of the relative roles of host phylogeography and dietary factors in shaping the gut microbiome of closely related mammalian hosts.

Public attitudes and intentions toward engaging in reintroduction of wolves to Japan.

Reintroducing apex predators is an important approach in ecosystem restoration; however, it is challenging. Wolves (Canis lupus) were exterminated in Japan around 1900, and since then, there has been a lack of top predators throughout the country. Currently, the wild ungulate population is increasing, causing agricultural and forest damage. This has triggered an ongoing debate among researchers and nongovernmental organizations on whether wolves should be reintroduced to promote self-regulating biodiverse ecosystems. We conducted a nationwide survey to examine public attitudes toward wolf reintroduction (WR) in Japan. We sent online questionnaires to 88,318 citizens across the country. Among the 12,028 respondents, excluding those with invalid or incomplete answers and unqualified respondents, we obtained and analyzed 7500 responses that were representative of Japanese citizens in terms of some key sociodemographic attributes. More respondents disagreed with WR (39.9%) than agreed (17.1%), and many respondents (43.0%) were undecided. Structural equation modeling revealed that risk perceptions affected public attitudes, implying that the greater the perceived threat of wolf attacks, the less likely people are to support WR. In contrast, attitudes toward wolves (e.g., "I like wolves.") influenced by wildlife value orientation and beliefs about the ecological role of wolves (e.g., controlling deer populations) positively affected public attitudes toward WR. Those who had a positive attitude toward WR showed intentions to engage in behaviors that support WR. Our results suggest that the dissemination of information related to the ecological role of wolves and the development of a more mutualistic mindset in people could positively influence public support for WR in Japan.

Actitudes e intenciones públicas respecto a la reintroducción de lobos en Japón Resumen La reintroducción de superdepredadores es una estrategia importante para la restauración de los ecosistemas; sin embargo, representa muchos retos. Los lobos (Canis lupus) fueron exterminados en Japón alrededor de 1900 y desde entonces no ha habido superdepredadores en el país. Hoy en día, la población silvestre de ungulados está incrementando y ocasionando daño agrícola y forestal. Esto ha detonado un debate entre los investigadores y las organizaciones no gubernamentales sobre si se debiesen reintroducir lobos para promover ecosistemas biodiversos autorregulados. Realizamos una encuesta nacional para analizar las actitudes públicas respecto a la reintroducción de lobos (RL) en Japón. Enviamos 88,318 cuestionarios virtuales a ciudadanos de todo el país. De los 12,028 respondientes, excluyendo a aquellos con respuestas inválidas o incompletas y a los respondientes no calificados, obtuvimos y analizamos 7500 respuestas representativas del ciudadano japonés en términos de algunas características sociodemográficas importantes. Hubo más respondientes en contra (39.9%) que a favor (17.1%) de la RL y todavía más respondientes (43.0%) no estaban decididos. El modelo de ecuación estructural reveló que las percepciones de riesgo impactaron sobre las actitudes públicas, lo que implica que entre mayor sea la amenaza percibida de los ataques de lobos, es menos probable que la gente apoye la RL. Como contraste, la orientación del valor de la fauna que influyó sobre las actitudes (p. ej.: "me gustan los lobos") y las creencias sobre el papel ecológico de los lobos (p. ej.: controlar las poblaciones de venados) tuvieron un impacto positivo en las actitudes respecto a la RL. Quienes tuvieron una actitud positiva respecto a la RL mostraron intenciones de apoyarla. Nuestros resultados sugieren que la divulgación de información relacionada con el papel ecológico de los lobos y el desarrollo de una mentalidad más mutualista en las personas podrían influir positivamente en el apoyo público para la RL en Japón.

Ecological consequences of herbivory by Japanese macaques (Macaca fuscata) on succession patterns of tree assemblages: A case of snowy regions in Japan.

Apart from frugivory, we have limited knowledge of the ecological consequences of primate herbivory. We aimed to ascertain the effects of spring folivory and winter bark/bud herbivory by Japanese macaques (Macaca fuscata) on tree species and succession patterns of cool-temperate forests with heavy snow. To evaluate the impact of herbivory on individual trees, we assessed the growth and mortality of trees consumed by simulating herbivory on nine tree species over 4 years. Additionally, we assessed the cumulative impacts of bark/bud herbivory observed at the tree community level by monitoring the patterns of natural herbivory for almost a decade and evaluating the structure of tree assemblages in places with different cumulative impacts of herbivory. The results of simulated herbivory showed that the mortality caused by both spring and winter herbivory was limited (<20%) for almost all tree species monitored; however, the simulated folivory led to delayed tree growth and/or weakening of tree architecture. In contrast, the simulated bark/bud herbivory sometimes resulted in overcompensation of the tree consumed. The multiyear monitoring of natural herbivory demonstrated that, while bark/bud herbivory did not reduced the diversity and biomass of tree assemblages, the cumulative impacts of natural herbivory could have affected the tree succession pattern, resulting in increasing the availability of bark/buds preferably fed by macaques. The key cause for this feedback effect of herbivory on available foods of macaques might be heavy snow conditions, which could physically and physiologically restrain the excessive bark/buds herbivory by macaques.

A strategy for wildlife management in depopulating rural areas of Japan.

Former ranges of wild animals have been reestablished in many developed countries. However, this reestablishment has led to increasing human-wildlife conflict in agroforest ecosystems. In Japan, human-wildlife conflict, such as crop raiding by and ecological impacts of wild ungulates and primates, is a serious problem in depopulated rural areas due to these animal range expansions and increased abundances. Japan's human population is predicted to decline by 24% by 2050, and approximately 20% of agricultural settlements will become completely depopulated. In this scenario, anthropogenic pressures on wildlife (e.g., hunting and habitat alteration) will continue to decrease and human-wildlife conflict will increase due to increasing wildlife recovery. Japan's local governments plan to slow range recovery, prevent species reestablishment, or remove recolonizing large mammals through lethal control. This strategy, however, is not cost-effective, and workforce shortages in depopulated communities make it infeasible. Moreover, the suppression of wildlife prevents the recovery of ecological functions and thus would degrade regional biodiversity. The declining pressure on wildlife that accompanies human depopulation will prevent the restoration of any past states of human-wildlife interaction. We suggest human-used areas in rural landscapes be aggregated in compact cities and that in transition zones between human settlements and depopulated lands that land-sharing approaches be applied. Concentrating management efforts in compact cities may effectively decrease human-wildlife conflict, rather than intensifying human pressures. Reforestation of depopulated lands may lead to recovery of wildlife habitats, their ecosystem functions, and regional biodiversity due to minimization of negative anthropogenic effects (land-sparing approach). Balancing resolution of human-wildlife conflict and ecological rewilding could become a new, challenging task for regional wildlife managers.

Una Estrategia para el Manejo de Fauna en Áreas Rurales Despobladas de Japón Resumen Las distribuciones geográficas históricas de algunos animales silvestres se han reestablecido en muchos países desarrollados. Sin embargo, este restablecimiento ha derivado en un incremento del conflicto humano - fauna en los ecosistemas agroforestales. En Japón, el conflicto humano - fauna, como el asalto de cultivos y los impactos ecológicos de los primates y ungulados, es un problema serio en las áreas rurales despobladas debido a la expansión de la distribución y al incremento en abundancia de estos animales. Está pronosticado que la población humana de Japón decline en un 24% para 2050 y ∼20% de los establecimientos agrícolas estarán completamente despoblados. Bajo este escenario, las presiones antropogénicas sobre la fauna (como la caza y la alteración del hábitat) continuarán disminuyendo y el conflicto humano - fauna incrementará debido a la recuperación de la fauna. El gobierno local de Japón planea retrasar la recuperación de las distribuciones, prevenir el restablecimiento de las especies o remover a los mamíferos mayores en proceso de recolonización por medio del exterminio. Sin embargo, esta estrategia no es rentable y la escasez de mano de obra en las comunidades despobladas hace que no sea una estrategia factible. Además, la supresión de fauna impide la recuperación de las funciones ecológicas, por lo que terminaría por degradar la biodiversidad regional. La reducción de la presión sobre la fauna que va de la mano con la despoblación humana prevendrá la recuperación de cualquier estado pasado de la interacción humano - fauna. Sugerimos que las áreas usadas por humanos en los paisajes rurales queden agregadas en ciudades compactas y que se apliquen estrategias de tierras compartidas en las zonas de transición entre los asentamientos humanos y las tierras despobladas. La concentración de los esfuerzos de manejo en las ciudades compactas podría disminuir efectivamente el conflicto humano - fauna en lugar de intensificar las presiones humanas. La reforestación de las tierras despobladas podría derivar en la recuperación del hábitat de la fauna, sus funciones ambientales y de la biodiversidad regional debido a la minimización de los efectos antropogénicos (estrategia de tierra parsimoniosa). El balance entre la resolución del conflicto humano - fauna y el retorno ecológico a la vida silvestre podría convertirse en una tarea nueva y exigente para los administradores regionales de la fauna.

Impact assessment of dam construction and forest management for Japanese macaque habitats in snowy areas.

Japanese macaques (Macaca fuscata) in their northernmost habitats represent a keystone species and play a central role in heavy snowfall ecosystems. However, distributions have been restricted by pre-war hunting, and populations are facing issues of natural forest losses caused by new dam constructions and massive conifer plantations. In the present study, we predicted the influences of these environmental conditions on macaque habitats during each season, and evaluated the effect of natural forest restoration as a mitigation measure. We constructed multiple habitat suitability models on the basis of different forest change scenarios, by using maximum entropy modeling (Maxent). We predicted the influence of each scenario by calculating the habitat unit (habitat quality × habitat quantity). We made the following predictions: (1) the influences of environmental conditions on habitat models vary seasonally, but dam construction destroys the optimum macaque habitats in every season; (2) restoration of conifer plantations to semi-natural forests does not always contribute to the improvement of total habitat unit, except in snowy seasons; and (3) in comparison with encouraging natural forest restoration in plantation areas and maintaining the standard-rotation plantation management, the implementation of long-rotation plantation in existing plantation areas provides more suitable alternative habitats for macaques in non-snowy seasons.

Influences of different large mammalian fauna on dung beetle diversity in beech forests.

This paper focuses on biological relationships between mammalian species richness and the community structure of dung beetles in cool-temperate forests in the northernmost part of mainland Japan. The composition of beetle assemblages was evaluated at 3 sites in undisturbed beech forests with different mammalian fauna. In spring and summer 2009, beetles were collected at each site using pitfall traps baited with feces from Japanese macaques, Macaca fuscata Blyth (Primates: Cercopithecidae); Asiatic black bears, Ursus thibetanus Cuvier (Carnivora: Ursidae); Japanese serows, Capricornis crispus Temminck (Artiodactyla: Bovidae); and cattle. In the present study, 1,862 dung beetles representing 14 species were collected, and most dung beetles possessed the ecological characteristic of selecting specific mammalian feces. The present findings indicated that although species diversity in dung beetle assemblages was not necessarily positively correlated with mammalian species richness in cool-temperate forests, the absence of the macaque population directly resulted in the marked reduction of the beetle abundance, with the loss of the most frequent species, Aphodius eccoptus Bates (Coleoptera: Scarabaeidae) during spring.

Influence of heavy snow on the feeding behavior of Japanese macaques (macaca fuscata) in northern Japan.

Natural disasters can degrade primate habitat and alter feeding behavior. Here, we examined the influence of unusually heavy snow on diet and feeding-site use by Japanese macaques (Macaca fuscata) in northern Japan. To compare the winter-feeding behavior under different snow conditions, we recorded the plant species foraged on by macaques in multiple transects of the Shirakami Mountains from 2008 to 2012 (excluding 2011). We used cluster analysis to describe foraged plant assemblages, and applied multiple dimensional scaling and decision tree modeling to evaluate annual variation in feeding-site use by macaques. Our cluster analysis revealed five types of foraged plant assemblages. The proportion of each type present in transects varied considerably across the years, indicating that the diet of macaques in heavy snow conditions was influenced more by resource accessibility than by preference. Multiple dimensional scaling and decision tree modeling demonstrated that heavy snow conditions restricted feeding-site use. Moreover, the distribution of refuges relative to severe external ambient environments was a stronger limiting factor for feeding-site use than was the availability of food resources. While most primate species facing unexpected starvation employ risk-prone foraging tactics (i.e., choosing the option with higher pay-off by accepting risk), Japanese macaques have a tendency to adopt risk-averse foraging behavior (i.e., minimizing energy loss when searching for preferred diet items under long-lasting heavy snow conditions), because winters with temperatures below freezing have higher thermoregulatory costs.

Resource use of Japanese macaques in heavy snowfall areas: implications for habitat management.

Populations of Japanese macaque (Macaca fuscata) that inhabit the northernmost distribution of any nonhuman primates have been listed as endangered in Japan; however, macaques are widely known for being pests that cause agricultural damage. This study identified priority areas for the conservation and management of macaque habitats, by comparing the resource use of troops occupying remote mountains (montane troops) against troops inhabiting disturbed forests adjacent to settlements (rural troops). We collected species presence data across 2 years by radio-tracking two montane troops and two rural troops in the Shirakami Mountains. We developed seasonal utilization distributions by using the kernel method, and identified habitat characteristics by using ecological-niche factor analysis (ENFA). Our results indicate that environmental factors influencing the potential habitat varied widely with season in montane troops as compared with that in rural troops. ENFA results demonstrated that rural troops exhibited more biased resource use and narrower niche breadths than montane troops. Based on our findings, we propose that (1) primary broadleaf forests are the spring habitat conservation priority of montane troops; (2) the habitat unit--the product of habitat suitability index and its surface area--for montane troops is enhanced by removing old conifer plantations from the forest edge at low elevations; (3) such removal around settlements may also contribute toward removing a frontline refuge for rural troops intruding farmlands; and (4) intensive prevention measures against macaque intrusions into settlements during the bottleneck snowy season contribute toward reducing the habitat unit of rural troops.