Makoto Nashimoto

Habitat availability and density estimations for the Japanese hare by fecal pellet counting

Abstract We aimed to clarify the factors that affect Japanese hare (Lepus brachyurus) densities and habitat availability in certain vegetation types. Using fecal pellet counts, we found that hare densities and habitat availability were higher in open–tree-canopy habitats with a dense ground cover of herbs and grasses, such as cleared areas in artificial forests. However, when we examined the relationships between fecal pellets as an indicator of hare density and various attributes of forest floor vegetation, no vegetation parameters had a significant correlation with fecal pellets among different plant communities. Thus, it is difficult to predict hare density based on forest floor vegetation, in general. However, in seven Japanese cedar (Cryptomeria japonica) plantation sites, high herb volume index and a low degree of canopy closure, calculated from fisheye-lens photographs, had a significant correlation with fecal pellet density (P = 0.029 and 0.006, respectively). Based on the relationships between fecal pellets and certain forest attributes (e.g., stand height and diameter at breast height of trees), we determined that fecal pellet density was higher in young stands in these plantations. This is likely because young stands have a larger volume of herbaceous species that provide food and shelter for hares, owing to the bright ground conditions resulting from the relatively open canopy. Appropriate plantation control such as cutting and planting trees is important for habitat conservation of L. brachyurus, because planted C. japonica forest occupies more than half of artificial forests in Japan.

GPS cell phone tracking in the Greater Tokyo Area: A field test on raccoon dogs

We tested instantaneous GPS cell phone telemetry to record movement data of raccoon dogs (Nyctereutes procyonoides) in Abiko city, Greater Tokyo, Japan. We monitored the changes in locations of six raccoon dogs in various land use types such as roads, golf courses, towns, rice and crop paddies, and forest. Data were downloaded instantaneously using cell phone networks and the internet, remotely to a desktop computer. We obtained 410 location points and the maximum duration of individual tracking was 144 hours. The success rate of GPS positioning varied among individuals. On average, the success rate of three raccoon dogs in a relatively open area was 98% and that of three raccoon dogs in a mosaic area was 70%. In total, 372 of the data points (91 % of all downloaded data) with reliable accuracy were used to analyze movement speed during the day time as well as habitat use of the raccoon dogs, revealing various spatial and temporal behavioral patterns. Human activities were the likely cause of characteristic behaviors in tall weed patches and golf courses, and daily patterns of movement. Our results indicate the potential utility of GPS cell phone tracking to efficiently monitor and manage wildlife in changing urban environments.