Ecological filtering shapes the impacts of agricultural deforestation on biodiversity.

The biodiversity impacts of agricultural deforestation vary widely across regions. Previous efforts to explain this variation have focused exclusively on the landscape features and management regimes of agricultural systems, neglecting the potentially critical role of ecological filtering in shaping deforestation tolerance of extant species assemblages at large geographical scales via selection for functional traits. Here we provide a large-scale test of this role using a global database of species abundance ratios between matched agricultural and native forest sites that comprises 71 avian assemblages reported in 44 primary studies, and a companion database of 10 functional traits for all 2,647 species involved. Using meta-analytic, phylogenetic and multivariate methods, we show that beyond agricultural features, filtering by the extent of natural environmental variability and the severity of historical anthropogenic deforestation shapes the varying deforestation impacts across species assemblages. For assemblages under greater environmental variability-proxied by drier and more seasonal climates under a greater disturbance regime-and longer deforestation histories, filtering has attenuated the negative impacts of current deforestation by selecting for functional traits linked to stronger deforestation tolerance. Our study provides a previously largely missing piece of knowledge in understanding and managing the biodiversity consequences of deforestation by agricultural deforestation.

Sharing land via keystone structure: Retaining naturally regenerated trees may efficiently benefit birds in plantations.

Meeting food/wood demands with increasing human population and per-capita consumption is a pressing conservation issue, and is often framed as a choice between land sparing and land sharing. Although most empirical studies comparing the efficacy of land sparing and sharing supported land sparing, land sharing may be more efficient if its performance is tested by rigorous experimental design and habitat structures providing crucial resources for various species-keystone structures-are clearly involved. We launched a manipulative experiment to retain naturally regenerated broad-leaved trees when harvesting conifer plantations in central Hokkaido, northern Japan. We surveyed birds in harvested treatments, unharvested plantation controls, and natural forest references 1-year before the harvest and for three consecutive postharvest years. We developed a hierarchical community model separating abundance and space use (territorial proportion overlapping treatment plots) subject to imperfect detection to assess population consequences of retention harvesting. Application of the model to our data showed that retaining some broad-leaved trees increased the total abundance of forest birds over the harvest rotation cycle. Specifically, a preharvest survey showed that the amount of broad-leaved trees increased forest bird abundance in a concave manner (i.e., in the form of diminishing returns). After harvesting, a small amount of retained broad-leaved trees mitigated negative harvesting impacts on abundance, although retention harvesting reduced the space use. Nevertheless, positive retention effects on the postharvest bird density as the product of abundance and space use exhibited a concave form. Thus, small profit reductions were shown to yield large increases in forest bird abundance. The difference in bird abundance between clearcutting and low amounts of broad-leaved tree retention increased slightly from the first to second postharvesting years. We conclude that retaining a small amount of broad-leaved trees may be a cost-effective on-site conservation approach for the management of conifer plantations. The retention of 20-30 broad-leaved trees per ha may be sufficient to maintain higher forest bird abundance than clearcutting over the rotation cycle. Retention approaches can be incorporated into management systems using certification schemes and best management practices. Developing an awareness of the roles and values of naturally regenerated trees is needed to diversify plantations.

Quantifying the impacts of 166 years of land cover change on lowland bird communities.

Land cover change for agriculture is thought to be a major threat to global biodiversity. However, its ecological impact has rarely been quantified in the Northern Hemisphere, as broad-scale conversion to farmland mainly occurred until the 1400s-1700s in the region, limiting the availability of sufficient data. The Ishikari Lowland in Hokkaido, Japan, offers an excellent opportunity to address this issue, as hunter-gatherer lifestyles dominated this region until the mid-nineteenth century and land cover maps are available for the period of land cover changes (i.e. 1850-2016). Using these maps and a hierarchical community model of relationships between breeding bird abundance and land cover types, we estimated that broad-scale land cover change over a 166-year period was associated with more than 70% decline in both potential species richness and abundance of avian communities. We estimated that the abundance of wetland and forest species declined by greater than 88%, whereas that of bare-ground/farmland species increased by more than 50%. Our results suggest that broad-scale land cover change for agriculture has led to drastic reductions in wetland and forest species and promoted changes in community composition in large parts of the Northern Hemisphere. This study provides potential baseline information that could inform future conservation policies.

A spatially explicit empirical model of structural development processes in natural forests based on climate and topography.

Stand structure develops with stand age. Old-growth forests with well-developed stand structure support many species. However, development rates of stand structure likely vary with climate and topography. We modeled structural development of 4 key stand variables and a composite old-growth index as functions of climatic and topographic covariates. We used a hierarchical Bayesian method for analysis of extensive snap-shot National Forest Inventory (NFI) data in Japan (n = 9244) to account for differences in stand age. Development rates of structural variables and the old-growth index exhibited curvilinear responses to environmental covariates. Flat sites were characterized by high rates of structural development. Approximately 150 years were generally required to attain high values (approximately 0.8) of the old-growth index. However, the predicted age to achieve specific values varied depending on environmental conditions. Spatial predictions highlighted regional variation in potential structural development rates. For example, sometimes there were differences of >100 years among sites, even in the same catchment, in attainment of a medium index value (0.5) after timber harvesting. The NFI data suggested that natural forests, especially old natural forests (>150 years), remain generally on unproductive ridges, steep slopes, or areas with low temperature and deep snow, where many structural variables show slow development rates. We suggest that maintenance and restoration of old natural forests on flat sites should be prioritized for conservation due to the likely rapid development of stand structure, although remaining natural forests on low-productivity sites are still important and should be protected.

Un Modelo Empírico Espacialmente Explícito de Procesos de Desarrollo Estructural en Bosques Naturales Basado en el Clima y la Topografía Resumen La estructura de un rodal se desarrolla con la edad. Los bosques maduros con una estructura bien desarrollada dan sustento a muchas especies. Sin embargo, las tasas de desarrollo de los rodales probablemente varían con el clima y la topografía. Modelamos el desarrollo estructural de 4 variables clave de un rodal y un índice de crecimiento antiguo compuesto como funciones de covariables climáticas y topográficas. Utilizamos un método bayesiano jerárquico para analizar datos (n = 9,244) en fotografías del inventario nacional forestal (INF) de Japón para entender las diferencias en la edad de los rodales. Las tasas de desarrollo de las variables estructurales y el índice de crecimiento antiguo mostraron respuestas curvilíneas a las covariables ambientales. Los sitios planos se caracterizaron por altas tasas de desarrollo estructural. Por lo general, se requerían 150 años para alcanzar valores altos (∼0.8) en el índice de crecimiento antiguo. Sin embargo, la edad prevista para alcanzar valores específicos varió dependiendo de las condiciones ambientales. Las predicciones espaciales pusieron de relieve la variación regional en las potenciales tasas de desarrollo estructural. Por ejemplo, a veces había diferencia de >100 años entre sitios, aun en la misma cuenca, en el consecución de un valor de índice medio (0.5) después de la cosecha de madera. Los datos de INF sugieren que los bosques naturales, especialmente los bosques maduros (>150 años) permanecen generalmente en crestas improductivas, pendientes pronunciadas o en áreas con baja temperatura y nieve profunda, donde muchas variables estructurales muestran tasas de desarrollo lentas. Sugerimos que el mantenimiento y la restauración de bosques naturales maduros en sitios planos deben priorizarse para conservación debido al probable desarrollo rápido de la estructura del rodal, aunque los bosques naturales restantes en sitios de baja productividad también son importantes y deben ser protegidos.

Seasonality in spatial distribution: Climate and land use have contrasting effects on the species richness of breeding and wintering birds.

AIM: Many studies have examined large-scale distributions of various taxa and their drivers, emphasizing the importance of climate, topography, and land use. Most studies have dealt with distributions over a single season or annually without considering seasonality. However, animal distributions and their drivers can differ among seasons because many animals migrate to suitable climates and areas with abundant prey resources. We aim to clarify seasonality in bird distributions and their drivers. LOCATION: Japan. METHODS: We examined the effects of climate (annual mean temperature, snow depth), topography (elevation), and land use (extent of surrounding habitat) on bird species richness, in the breeding and wintering seasons separately, using nationwide data (254 forest and 43 grassland sites, respectively). We separately analyzed the species richness of all species, residents, short-, and long-distance migrants in forests and grasslands. RESULTS: In the breeding season, the annual mean temperature negatively affected all groups (except for forest and grassland residents), and the extent of surrounding habitat positively affected many groups. By contrast, in the wintering season, temperature positively affected all groups (except for forest residents), and the extent of surrounding habitat positively affected only grassland long-distance migrants. In both seasons, the species richness of forest and grassland residents was high in regions of moderate and high temperature, respectively. Moreover, snow depth negatively affected all forest groups in the wintering season. Mapping expected species richness suggested that regions with different climates served as habitats for different groups during different seasons. MAIN CONCLUSIONS: All regions were important bird habitats depending on the season, reflecting the contrasting effects of temperature across seasons. In the breeding season, surrounding land use was also an important driver. To understand the seasonal role that each region and environment plays in maintaining species/communities, a large-scale study considering both environmental seasonality and species distribution is needed.

Analyzing community structure subject to incomplete sampling: hierarchical community model vs. canonical ordinations.

Recently developing hierarchical community models (HCMs) accounting for incomplete sampling are promising approaches to understand community organization. However, pros and cons of incorporating incomplete sampling in the analysis and related design issues remain unknown. In this study, we compared HCM and canonical redundancy analysis (RDA) carried out with 10 different dissimilarity coefficients to evaluate how each approach restores true community abundance data sampled with imperfect detection. We conducted simulation experiments with varying numbers of sampling sites, visits, mean detectability and mean abundance. Performance of HCM was measured by estimates of "expected" (mean) abundance ( λ^ij ) and realized abundance ( N^ij : direct estimate of site- and species-specific abundance). We also compared HCM and different types of RDA (normal, partial, and weighted), all performed with the same ten different dissimilarity coefficients, with unequal number of visits to sampling sites. In addition, we applied the models to a virtual survey carried out on the Barro Colorado Island tree plot data for which we know true community abundance. Simulation experiments showed that N^ij yielded by HCM best restored the underlying abundance of constituent species among 12 abundance estimates by HCM and RDA regardless if the sampling was equal or unequal. Mean abundance predominantly affected the performance of HCM and RDA while λ^ij yielded by HCM had comparable performance to percentage difference and Gower dissimilarity coefficients of RDA. Relative performance of RDA types depended on the combination of dissimilarity coefficients and the distribution of sampling effort. Best performance of N^ij followed by λ^ij , percentage difference and Gower dissimilarity were also observed for the analysis of tree plot data, and graphical plots (triplots) based on λ^ij rather than N^ij clearly separated the effects of two environmental covariates on the abundance of constituent species. Under our conditions of model evaluation and the method, we concluded that, in terms of assessing the environmental dependence of abundance, HCMs and RDA can have comparable performance if we can choose appropriate dissimilarity coefficients for RDA. However, since HCMs provide straightforward biological interpretations of parameter estimates and flexibility of the analysis, HCMs would be useful in many situations as well as conventional canonical ordinations.

Genomic reconstruction of 100 000-year grassland history in a forested country: population dynamics of specialist forbs.

Grassland ecosystems worldwide have been extensively converted to other land uses and are globally imperiled. Because many grasslands have been maintained by human activities, understanding their origin and history is fundamentally important to better contemporary management. However, existing methods to reconstruct past vegetation can produce contrasting views on grassland history. Here, we inferred demographic histories of 40 populations of four grassland forb species throughout Japan using high-resolution genome sequences and model-flexible demographic simulation based on the site frequency spectrum. Although two species showed a slight decline in population size between 100 000-10 000 years ago, our results suggest that population sizes of studied species have been maintained within the range of 0.5-2.0 times the most recent estimates for at least 100 000 years across Japan. Our results suggest that greater than 90% declines in Japanese grasslands and subsequent losses of grassland species in the last 100 years are geologically and biologically important and will have substantial consequences for Japanese biota and culture. People have had critical roles in maintaining disturbance-dependent grassland ecosystems and biota in this warm and wet forested country. In these contexts, disturbances associated with forest harvesting and traditional extensive farming have the potential to maintain grassland ecosystems and can provide important opportunities to reconcile resource production and conservation of grassland biodiversity.

Meta-analysis of management effects on biodiversity in plantation and secondary forests of Japan.

Conservation of temperate forest biodiversity has historically focused on natural old-growth. Less than 3% of the world's temperate forests remain unmodified by humans, however, and much of temperate-forest biodiversity is held in the predominating planted and secondary forests. Japan provides a widely applicable model for examining how to maximize biodiversity in managed temperate forests, because of its richness of forestry research generated from its vast forest area, albeit largely in Japanese, and the wide practice of its dominant management interventions across the northern temperate zone. Management for plantations includes thinning, extended rotation cycles and clear-cutting. For secondary forests regenerating from past clearance, traditional management varies in its intensities, from clear-cutting as coppices to small-scale understory clearance. Here we provide a first synthesis of published research on biodiversity in planted and secondary forests of Japan, relevant to management of these types of forest in northern temperate regions. Systematic review and meta-analyses of papers published in English and Japanese quantified management impacts on species richness and abundance of several taxa, in relation to moderator variables including stand age and management intensity. Plantation thinning substantially increases the richness and abundance of several taxa. Effect sizes decline with time since thinning for the abundance of regenerating saplings and seedlings, necessitating repeated thinning treatments every 6 years to sustain this positive effect. Taxonomic groups exhibit variable relationships with stand age in both planted and secondary forests, indicating a need to include both young and old forest stands in managed forest mosaics. We find an insufficient evidence base is available to allow for a meaningful synthesis of low-intensity management effects in historically managed secondary forests, with studies varying widely in scale and reported outcomes. We outline an agenda for the research community to achieve a systematic evaluation of scale-dependent effects of traditional forest management on biodiversity.

Health Benefits of Urban Allotment Gardening: Improved Physical and Psychological Well-Being and Social Integration.

With an ever-increasing urban population, promoting public health and well-being in towns and cities is a major challenge. Previous research has suggested that participating in allotment gardening delivers a wide range of health benefits. However, evidence from quantitative analyses is still scarce. Here, we quantify the effects, if any, of participating in allotment gardening on physical, psychological and social health. A questionnaire survey of 332 people was performed in Tokyo, Japan. We compared five self-reported health outcomes between allotment gardeners and non-gardener controls: perceived general health, subjective health complaints, body mass index (BMI), mental health and social cohesion. Accounting for socio-demographic and lifestyle variables, regression models revealed that allotment gardeners, compared to non-gardeners, reported better perceived general health, subjective health complaints, mental health and social cohesion. BMI did not differ between gardeners and non-gardeners. Neither frequency nor duration of gardening significantly influenced reported health outcomes. Our results highlight that regular gardening on allotment sites is associated with improved physical, psychological and social health. With the recent escalation in the prevalence of chronic diseases, and associated healthcare costs, this study has a major implication for policy, as it suggests that urban allotments have great potential for preventative healthcare.

Gardening is beneficial for health: A meta-analysis.

There is increasing evidence that gardening provides substantial human health benefits. However, no formal statistical assessment has been conducted to test this assertion. Here, we present the results of a meta-analysis of research examining the effects of gardening, including horticultural therapy, on health. We performed a literature search to collect studies that compared health outcomes in control (before participating in gardening or non-gardeners) and treatment groups (after participating in gardening or gardeners) in January 2016. The mean difference in health outcomes between the two groups was calculated for each study, and then the weighted effect size determined both across all and sets of subgroup studies. Twenty-two case studies (published after 2001) were included in the meta-analysis, which comprised 76 comparisons between control and treatment groups. Most studies came from the United States, followed by Europe, Asia, and the Middle East. Studies reported a wide range of health outcomes, such as reductions in depression, anxiety, and body mass index, as well as increases in life satisfaction, quality of life, and sense of community. Meta-analytic estimates showed a significant positive effect of gardening on the health outcomes both for all and sets of subgroup studies, whilst effect sizes differed among eight subgroups. Although Egger's test indicated the presence of publication bias, significant positive effects of gardening remained after adjusting for this using trim and fill analysis. This study has provided robust evidence for the positive effects of gardening on health. A regular dose of gardening can improve public health.

Estimating species - area relationships by modeling abundance and frequency subject to incomplete sampling.

Models and data used to describe species-area relationships confound sampling with ecological process as they fail to acknowledge that estimates of species richness arise due to sampling. This compromises our ability to make ecological inferences from and about species-area relationships. We develop and illustrate hierarchical community models of abundance and frequency to estimate species richness. The models we propose separate sampling from ecological processes by explicitly accounting for the fact that sampled patches are seldom completely covered by sampling plots and that individuals present in the sampling plots are imperfectly detected. We propose a multispecies abundance model in which community assembly is treated as the summation of an ensemble of species-level Poisson processes and estimate patch-level species richness as a derived parameter. We use sampling process models appropriate for specific survey methods. We propose a multispecies frequency model that treats the number of plots in which a species occurs as a binomial process. We illustrate these models using data collected in surveys of early-successional bird species and plants in young forest plantation patches. Results indicate that only mature forest plant species deviated from the constant density hypothesis, but the null model suggested that the deviations were too small to alter the form of species-area relationships. Nevertheless, results from simulations clearly show that the aggregate pattern of individual species density-area relationships and occurrence probability-area relationships can alter the form of species-area relationships. The plant community model estimated that only half of the species present in the regional species pool were encountered during the survey. The modeling framework we propose explicitly accounts for sampling processes so that ecological processes can be examined free of sampling artefacts. Our modeling approach is extensible and could be applied to a variety of study designs and allows the inclusion of additional environmental covariates.

Traffic noise reduces foraging efficiency in wild owls.

Anthropogenic noise has been increasing globally. Laboratory experiments suggest that noise disrupts foraging behavior across a range of species, but to reveal the full impacts of noise, we must examine the impacts of noise on foraging behavior among species in the wild. Owls are widespread nocturnal top predators and use prey rustling sounds for localizing prey when hunting. We conducted field experiments to examine the effect of traffic noise on owls' ability to detect prey. Results suggest that foraging efficiency declines with increasing traffic noise levels due to acoustic masking and/or distraction and aversion to traffic noise. Moreover, we estimate that effects of traffic noise on owls' ability to detect prey reach >120 m from a road, which is larger than the distance estimated from captive studies with bats. Our study provides the first evidence that noise reduces foraging efficiency in wild animals, and highlights the possible pervasive impacts of noise.

Both Direct and Vicarious Experiences of Nature Affect Children's Willingness to Conserve Biodiversity.

Children are becoming less likely to have direct contact with nature. This ongoing loss of human interactions with nature, the extinction of experience, is viewed as one of the most fundamental obstacles to addressing global environmental challenges. However, the consequences for biodiversity conservation have been examined very little. Here, we conducted a questionnaire survey of elementary schoolchildren and investigated effects of the frequency of direct (participating in nature-based activities) and vicarious experiences of nature (reading books or watching TV programs about nature and talking about nature with parents or friends) on their affective attitudes (individuals' emotional feelings) toward and willingness to conserve biodiversity. A total of 397 children participated in the surveys in Tokyo. Children's affective attitudes and willingness to conserve biodiversity were positively associated with the frequency of both direct and vicarious experiences of nature. Path analysis showed that effects of direct and vicarious experiences on children's willingness to conserve biodiversity were mediated by their affective attitudes. This study demonstrates that children who frequently experience nature are likely to develop greater emotional affinity to and support for protecting biodiversity. We suggest that children should be encouraged to experience nature and be provided with various types of these experiences.

The Distribution of Cool Spots as Microrefugia in a Mountainous Area.

It has recently been proposed that microrefugia played an important role in species survival during past climate change events. However, the current distributions of microrefugia remain largely unknown. Wind-hole sites are areas affected by preferential flows of cool air generated in interstitial spaces created by rock fragments or colluvia. Alpine plant species occurring in lowland wind-hole sites isolated from alpine zones may be relicts of the last glacial period. Hokkaido, northern Japan, is known to contain many wind-hole sites in which alpine plant species can occur. Here we surveyed 55 wind-hole sites in the Kitami region, eastern Hokkaido, and observed two alpine plant species (lingonberry, Vaccinium vitis-idaea, and Labrador tea, Rhododendron groenlandicum ssp. diversipilosum var. diversipilosum) in 14 wind-hole sites. Statistical modeling showed that wind-hole sites are likely to occur in areas with high maximum slope angles and volcanic rock cover, and concave surfaces. Our predictions of wind-hole site distributions suggest that such topographic conditions are common in our study area, and that many undiscovered wind-hole sites exist. Ignoring microhabitats may greatly underestimate species distributions in topographically complex regions, and dispersed cool spots may also function as stepping stones and temporal habitats for cold-adapted species. Because these localized unique habitats usually occur in economically unproductive sites, identifying and protecting potential microrefugia (cool spots) would be a robust and cost-effective mitigation of climate change impacts.

Use of two population metrics clarifies biodiversity dynamics in large-scale monitoring: the case of trees in Japanese old-growth forests: the need for multiple population metrics in large-scale monitoring.

Many indicators/indices provide information on whether the 2010 biodiversity target of reducing declines in biodiversity have been achieved. The strengths and limitations of the various measures used to assess the success of such measures are now being discussed. Biodiversity dynamics are often evaluated by a single biological population metric, such as the abundance of each species. Here we examined tree population dynamics of 52 families (192 species) at 11 research sites (three vegetation zones) of Japanese old-growth forests using two population metrics: number of stems and basal area. We calculated indices that track the rate of change in all species of tree by taking the geometric mean of changes in population metrics between the 1990s and the 2000s at the national level and at the levels of the vegetation zone and family. We specifically focused on whether indices based on these two metrics behaved similarly. The indices showed that (1) the number of stems declined, whereas basal area did not change at the national level and (2) the degree of change in the indices varied by vegetation zone and family. These results suggest that Japanese old-growth forests have not degraded and may even be developing in some vegetation zones, and indicate that the use of a single population metric (or indicator/index) may be insufficient to precisely understand the state of biodiversity. It is therefore important to incorporate more metrics into monitoring schemes to overcome the risk of misunderstanding or misrepresenting biodiversity dynamics.

Plantation vs. natural forest: matrix quality determines pollinator abundance in crop fields.

In terrestrial ecosystems, ecological processes and patterns within focal patches frequently depend on their matrix. Crop fields (focal patches) are often surrounded by a mosaic of other land-use types (matrix), which may act as habitats for organisms and differ in terms of the immigration activities of organisms to the fields. We examined whether matrix quality affects wild pollinator abundance in crop fields, given that the species (Apis cerana) generally nest in the cavities of natural trees. We examined fields of a pollination-dependent crop surrounded by plantations and natural forests, which comprised the matrix. Our analysis revealed a clear positive effect of the natural forest on the pollinator abundance, but the plantation forest had little effects. These indicate that agricultural patches are influenced by their matrix quality and the resulting crop pollinator abundance, suggesting the importance of matrix management initiatives such as forest restoration surrounding agricultural fields to improve crop production.

Relative importance of the area and shape of patches to the diversity of multiple taxa.

Although enhancing reserve shape has been suggested as an alternative to enlarging nature reserves, the importance of reserve shape relative to reserve area remains unclear. Here we examined the relative importance of area and shape of forest patches to species richness, species composition, and species abundance (abundance of each species) for 3 taxa (33 birds, 41 butterflies, and 91 forest-floor plants) in a fragmented landscape in central Hokkaido, northern Japan. We grouped the species according to their potential edge responses (interior-, neutral-, and edge-species groups for birds and forest-floor plants, woodland- and open-land-species groups for butterflies) and analyzed them separately. We used a shape index that was independent of area as an index of shape circularization. Hierarchical partitioning and variation partitioning revealed that patch area was generally more important than patch shape for species richness and species composition of birds and butterflies. For forest-floor plants, effects of patch area and shape were small, whereas effects of local forest structure were large. Patch area and circularization generally increased abundances of interior species of birds and forest-floor plants and woodland species of butterflies. Nevertheless, only patch circularization increased abundances of 1 woodland species of butterfly and 2 and 6 interior species of birds and forest-floor plants, respectively. We did not find any significant interaction effects between patch area and shape. Our results suggest that although reserves generally should be large and circular, there is a trade-off between patch area and shape, which should be taken into consideration when managing reserves.

Flower-visiting behavior of male bees is triggered by nectar-feeding insects.

Bees are important pollinators for many flowering plants. Female bees are thought to be more effective pollinators than male bees because they carry much more pollen than males. Males of some solitary bee species are known to patrol near flowers that females visit. Because patrolling males visit flowers to mate or defend their territories, they may function as pollinators. However, the significance of patrolling males to pollination has not been studied. We studied males of a solitary bee, Heriades fulvohispidus (Megachilidae), patrolling near flowers and visiting flowers that attracted nectar-feeding insects, including conspecifics, on the Ogasawara (Bonin) Islands. To test the hypothesis that patrolling male bees may function as pollen vectors, we compared the frequency of visits by H. fulvohispidus to flowers of an endemic plant, Schima mertensiana (Theaceae); comparisons were made among flowers with a dead H. fulvohispidus, a dead beetle, a piece of plastic, and nothing (control flowers). Patrolling H. fulvohispidus more frequently visited flowers with a dead conspecific, a dead beetle, or a piece of plastic than the control flowers. Our experiment demonstrates that nectar-feeding insects (including conspecifics and other insects) enhance the flower-visiting frequency of patrolling H. fulvohispidus males on S. mertensiana flowers. Furthermore, we observed S. mertensiana pollen on patrolling males as well as females, suggesting that male bees may also function as pollen vectors.

Sexual and male horn dimorphism in Copris ochus (Coleoptera: Scarabaeidae).

Copris ochus (Coleoptera: Scarabaeidae), an endangered species, is the largest dung beetle in Japan. In C. ochus, males have a long head horn, while females lack this long horn (sexual dimorphism). Very large males of C. ochus have disproportionately longer head horns than small males, suggesting male horn dimorphism, although the dimorphism has not been investigated quantitatively. To clarify sexual and male horn dimorphism in C. ochus quantitatively, we examined the scaling relationship between body size (prothorax width) and head horn length in 94 females and 76 males. These beetles were captured during July 1978 from a natural population on Mt. Aso in southwestern Japan using a light trap. Although the horn length of the females and males scaled with prothorax width, the scaling relationship differed between the sexes, i.e., the relationship was linear in females and nonlinear in males. Statistical tests for dimorphism in male horn length showed a significant discontinuous relationship, thus indicating distinct sexual and male dimorphism in head horns. Long- and short-horned C. ochus males may have different reproductive behaviors, as described in other horned dung beetles.