In this study, we describe a transition in the distribution of Japanese serow (Capricornis crispus) in the Suzuka Mountains Japanese Serow Protection Area, along the border between the Mie and Shiga Prefectures. We sampled serow distributions using camera traps at high and low elevations and light census methods in high elevation areas. Two and five cameras were placed in high elevation areas in 2014 and 2015, respectively, and light censuses were conducted monthly, except during the snowy season. Additionally, we placed two and four cameras in low elevation areas in 2014 and 2015, respectively. Despite a report of high serow density in the 1970s in high elevation areas, we found no evidence of the species. However, in low elevation areas, where serows were rarely found in the 1970s, we found the species at all camera locations and confirmed the birth of offspring. These results show that the distribution of serows in the protected area is contracting. Second, we documented changes in serow distribution by analyzing the results of monitoring data collected five times at 5-9-year intervals. In the 1980s, serow density in the center of the protected area (high elevation) was greater than that along the edges (low elevation). More recently, this pattern changed such that densities declined in both areas. In contrast, the density of Sika deer (Cervus nippon) has increased rapidly. The effect of increasing populations of Sika deer on Japanese serow density should be examined, and an action plan for serow conservation should be developed.
We conducted a comparative experiment to investigate the suitability of cage traps for efficiently capturing invasive crayfish (Pacifastacus leniusculus) in Lake Harutori, Hokkaido, Japan. For the experiment, we set up three types of cage traps (conger cage, crab cage and shrimp cage) in five spots along the lakeside. The result of the experiment revealed that the numbers of P. leniusculus captured were significantly higher for the conger cage than for the other cages. In addition, both the smallest individual and the largest individual of all captured individuals were captured by the conger cage. Moreover, the averages of body size of captured individuals were no significantly different between conger cage and the other cages. Thus, we concluded that the conger cage is the most efficient trap to capture crayfish in Lake Harutori.
Crop damage by wildlife is a worldwide concern, and countermeasures against the damage have been developed. However, techniques against damage have not effectively decreased crop damage. One reason for this problem is that the new techniques have not always been used. In this study, Rogers' model (innovation diffusion model) was used to reveal the factors restricting the spread of new knowledge to decrease damage. Rogers' model suggested that knowledge about a technique leads to positive feelings and satisfaction, and that positive feelings promote innovation. In this study, a simple electric fence was targeted as a technical innovation, and the aim was to reveal factors limiting diffusion of this innovation. The results showed that Rogers' model was applicable only to the group that attended a lecture, and that the model could not be adapted without a lecture. Therefore, wildlife managers should provide information directly, as indirect methods, such as mass communication media and advertisements, were inefficient. Incorrect use of the electric fence occurred frequently; therefore, the main reason for providing information directly was to reduce incorrect usage of the technique.