Ecotourism is often viewed as a mutually beneficial solution for both people and nature; however, unregulated wildlife tourism can inadvertently harm the wildlife. To enhance management practices, we conducted a study on rabbit tourism involving Amami rabbits (Pentalagus furnessi) which can be sighted by car driving at a Natural World Heritage Site in Japan. Because the sighting rate of wildlife under different car schedules and in varying density scenarios remains unknown, our study employed wildlife disturbance experiments and model simulation to estimate the recovery rate of rabbits after being flushed by tourists in different density and car schedule scenarios. Our analysis revealed that implementing a 20-minute time lag for the following car resulted in a 90% recovery rate for Amami rabbits. Additionally, adhering to a regular car schedule provided an increase in sighting rates of the rabbit compared to random and normal schedules by approximately 1.85 and 2.4 times, respectively, under optimal conditions (maximum density and 50 cars). Finally, we evaluated the profitability of the tourism industry under different densities of rabbits and rates of the money-back guarantee. Though introducing more cars appears to generate greater profits, it may simultaneously lead to a decrease in the rabbit sighting rate and an increased likelihood of activating the money-back guarantee. In conclusion, our findings clearly showed that considering both animal behavior in response to humans and human interest (i.e., MBG) in developing a tourism management system can achieve a simultaneous resolution of profitability and reduction in the impact of overutilization.
Abstract Agricultural birds are declining due to farmland abandonment and agricultural intensification, and monitoring approaches, including efficient survey methods, are crucial for the development of effective conservation strategies. Roadside surveys (RS), especially those using vehicle-mounted video cameras, can be used to efficiently search for targets; however, they are limited by the unknown detection range. Distance sampling (DS), in which animal density or abundance is estimated from the distance between the observer and the detected individual, can provide a complimentary approach to address this limitation of RS. We developed a DS model robust to location uncertainty based on video-based RS. We integrated location errors determined by an independent field test using RS and unmanned aerial vehicles (UAVs) into a stochastic DS model. We estimated the abundance of herons and egrets in farmlands in and around the evacuation zone of the Fukushima Daiichi nuclear power plant accident by combining RS and DS. The video-based RS covered 7,031 km of roads and 24.41 km 2 of farmlands. All herons and egrets were observed around the evacuation zone and none were detected in the zone. The predicted abundance of herons and egrets differed substantially between areas inside (0.0158 ± 0.0174/km 2 ) and outside of the zone (4.62 ± 5.41/km 2 ). Integrating location uncertainty into the DS model did not affect predicted heron and egret population densities (4.62 ± 5.41 vs. 4.66 ± 5.45/km 2 , with or without integrating location uncertainty, respectively). Accordingly, our survey method combining RS and DS is robust to location uncertainty. The study system (i.e., herons and egrets in farmlands) and the inability of location error to exceed the size of one farmland separated by levees may contribute to the accuracy of RS in this study. Synthesis and Applications: Combining RS with vehicle-mounted cameras and DS considering location uncertainty is widely applicable to open land species and can improve the efficiency of monitoring. When large location errors are expected by conventional approaches, DS models incorporating location uncertainty determined by RS and UAVs could be effective for abundance estimation over wide areas.
Land abandonment may decrease biodiversity but also provides an opportunity for rewilding. It is therefore necessary to identify areas that may benefit from traditional land management practices and those that may benefit from a lack of human intervention. In this study, we conducted comparative field surveys of butterfly occurrence in abandoned and inhabited settlements in 18 regions of diverse climatic zones in Japan to test the hypotheses that species-specific responses to land abandonment correlate with their climatic niches and habitat preferences. Hierarchical models that unified species occurrence and their habitat characteristics revealed that negative responses to land abandonment were associated with species having cold climatic niches utilizing open habitats, suggesting that traditional land use by human had long mitigated climate warming since the last glacier maximum through creating non-forest open habitats. Maps representing species gains and losses due to land abandonment, which were created from the model estimates, showed similar geographic patterns, but some parts of areas exhibited high species losses relative to gains. A hierarchical trait-based approach presented here revealed to be useful for scaling up local-scale effect of land abandonment to a macro-scale assessment, which is crucial to developing spatial conservation strategies in the era of depopulation.
The genetic diversity of a taxon has often been estimated by genetic diversity measures. However, they assume random sampling of individuals which is often inapplicable. Except when the distribution of the taxon is limited, researchers conventionally choose several sampling locations from the known distribution and then collect individuals from each location. Spatial sampling is a formalized version of the conventional sampling, which objectively provides geographically even sampling locations to cover genetic variation in a taxon assuming isolation by distance. To evaluate the validity of the spatial sampling in estimating genetic diversity, we conducted coalescent simulation experiments. The sampling locations were selected by spatial sampling and one sample was collected from each location for the sake of theoretical simplicity. We also devised a new measure of genetic diversity, ς, which assumes spatial sampling and is independent of allele frequency. This new measure places an emphasis on rare and phylogenetically distant alleles which have relatively small effect on nucleotide diversity. Therefore, it can complementarily serve for conservation studies although it cannot be used to estimate population mutation rate. We compared ς with the other diversity measures in the experiments. Nucleotide diversity, expected heterozygosity and ς showed within 3% relative biases on average while Watterson's theta was 31% overestimation on average. Thus, genetic diversities other than Watterson's theta held good robustness under the spatial sampling.
Citizen science is an important approach to monitoring for biodiversity conservation because it allows for data acquisition or analysis on a scale that is not possible for researchers alone. In citizen science projects, the use of online training is increasing to improve such skills. However, the effectiveness of quiz-style online training, assumed to be efficient to enhance participants’ skills, has not been evaluated adequately on species identification for citizen science biodiversity monitoring projects. Memory mechanisms in adaptive learning were hypothesized to guide the development of quiz-based online training tools for learning birdsong identification and for improving interest in birds and natural environments. To examine the hypothesis, we developed a quiz-style online training tool called TORI-TORE. We experimentally applied TORI-TORE in Fukushima, Japan, and examined its effectiveness for bird identification training using test scores and questionnaires to determine participants’ attitudes in a randomized control trial. We obtained the following key results: (1) TORI-TORE had positive effects on test scores and trainees’ attitudes toward birds. (2) Adaptive training, in which questions focused preferentially on unmastered bird species based on the answer history of individual trainees inspired by adaptive learning, unexpectedly led to lower scores and satisfaction in TORI-TORE. (3) Focusing on species that are relatively easy to remember, short lag times between training and testing, and long question intervals positively affected scores. While there is room for improvement, we expect TORI-TORE to contribute to online capacity building and to increase interest in natural environments.
Land abandonment may decrease biodiversity but also provides an opportunity for rewilding. It is therefore necessary to identify areas that may benefit from traditional land management practices and those that may benefit from a lack of human intervention. In this study, we conducted comparative field surveys of butterfly occurrence in abandoned and inhabited settlements in 18 regions of diverse climatic zones in Japan to test the hypotheses that species-specific responses to land abandonment correlate with climatic niches and habitat preferences. Hierarchical models that unified species occurrence and habitat preferences revealed that negative responses to land abandonment were associated with species that have cold climatic niches and use open habitats, suggesting that species negatively impacted by land abandonment will decline more due to future climate warming. Maps representing species gains and losses due to land abandonment, which were created from the model estimates, showed similar geographical patterns, but some areas exhibited high species losses relative to gains. Our hierarchical modelling approach was useful for scaling up local-scale effects of land abandonment to a macro-scale assessment, which is crucial to developing spatial conservation strategies in the era of depopulation.
Abstract Past land-use activity has massively altered the environment and vegetation over centuries, resulting in range contractions and expansions of species. When habitat recovery and species recolonization require a long time, the fingerprint of past land use can remain on the current distribution of species. To evaluate millennial-scale effects of land use in Japan, we explained the current ranges of 29 mammalian genera based on three types of archaeological land-use patterns (settlement, ironwork and kiln) considering potential confounding factors. The results indicate that archaeological human activity associated with ironwork and pottery production had severe negative effects on many genera of small and medium-sized mammals. Despite positive effects on some genera, the magnitudes were less than those of the negative effects. The relative importance of archaeological factors on small mammals was greater than those for medium- to-large mammals. The persistent imprint of past land-use patterns was non-negligible, explaining current mammalian diversity. Spatial ecological and archaeological information can provide meaningful insights into long-term socio-ecological processes, which are crucial for the development of sustainable societies in the Anthropocene.
Abstract 1. Conservation biologists have a daunting task of understanding the causes of species decline associated with anthropogenic factors and predicting the extinction risk of a growing number of endangered species. By stabilising estimates with information on closely related species, phylogenetic information among species can bridge gaps in information on species with small sample sizes when modelling large numbers of endangered species. However, modelling many species with the Gaussian process (GP), which underlies the evolutionary process of phylogenetic random effects, remains a challenge owing to the computational burden in estimating the large variance–covariance matrix. 2. Here, we applied a phylogenetic generalised mixed model with random slopes and random intercepts to 1,010 endangered vascular plant taxa in Japan following phylogenetic GPs implemented by nearest neighbour GP (NNGP) approximation. NNGP enables flexibility in changing the proximity on the phylogenetic tree of species from which information is borrowed to stabilise parameter estimates with a realistic computational burden. We evaluated the effectiveness of phylogenetic models by comparing the predictive performance and descriptive power of phylogenetic and non-phylogenetic models and identified the anthropogenic factors contributing to the decline of each of the studied endangered species. 3. We found that the model with phylogenetic information had better prediction performance than the model without phylogenetic information. The results showed that across all explanatory variables, the phylogenetic model could detect interspecific differences in response to environmental factors in a number of species more clearly. Combined with the phylogenetic signal results, we could also detect a phylogenetic bias in the species that could benefit from the positive effects of protected areas but reduce the extinction risk of 95% of all studied taxa. 4. In conclusion, our model, considering phylogenetic information with NNGP, allows the elucidation of factors causing the decline of many endangered species. In future analyses, the estimation of extinction probability linked to environmental change using such modelling might be applied to future climate–land use scenarios, advancing the comprehensive assessment of biodiversity degradation and threats to species at multiple scales.
Abstract Invasive predators not only cause native prey populations to decline but can also induce evolutionary changes in their behaviour in a short time scale. However, few studies have reported these rapid responses. This could be because strong predation pressure by invasive species often causes the extinction of native prey before an evolutionary effect can be detected. Recently, eradication projects successfully removed invasive predators and resulted in the recovery of native prey. We predicted that rapid responses can be detected by evaluating the behavioural traits of native prey populations having different histories of predator invasion. We examined the behavioural responses of a native frog, the Amami tip‐nosed frog ( Odorrana amamiensis ), to an invasive mongoose ( Herpestes auropunctatus ) on Amami Island, Japan. The native frog population was reduced by the mongoose; however, the eradication project leads to the recovery of the native frog population, thereby providing an opportunity to evaluate the evolutionary impact of the invasive species. We hypothesized that spatial differences in flight initiation distance ( FID ) can be explained by spatial patterns of past mongoose predation pressure. We used a spatial model based on generalized least squares regression methods to test the effects of potential factors on FID . We then performed model comparison and model averaging. We found that the native frog became more sensitive to the approach of a potential predator as the historical impact of the mongoose increased, suggesting that past strong predation pressure by the mongoose drove a rapid behavioural response in the native frog. Our study suggests that rapid behavioural responses of other native species can be detected not only after successful eradication projects, but also on currently invaded sites with different invasion histories.
