Amami rabbit

Abstract: Amami Island has many terrestrial wildlife species and subspecies that are endemic to the Nansei Archipelago. Many of them live in the forest ecosystems, while young secondary forests have replaced the majority of the original forests due to the past clear-cutting forestry. Of those species, the great scaly thrush Zoothera dauma major, Owston white-backed woodpecker Drendrocopos leucotos owstoni, long-haired rat Diplothrix legata and Amami pygmy woodpecker Dendrocopos kizuki amamii, appear to be so dependent on the mature forests (uncut for at least 50 years after selective felling) that their numbers must have decreased at least for the last few decades. On the other hand, the populations of Amami rabbit Pentalagus furnessi, purple jay Garrulus lidthi, Amami woodcock Scolopax mira, Ryukyu robin Erithacus komadori and spinous rat Tokudaia osimensis have decreased in the central part of the island, where mongoose numbers have skyrocketed in recent years. In the mean time, forestry practices that turned out to be economically unprofitable have resulted in a precipitous decline in production in the early 1990s. Mongoose control has also encountered critical financial problems due to the ignorance of the local community. These situations are rooted in a local economy that has been deeply dependent on government subsidies, which facilitated various development activities.

Abstract: The Amami rabbit Pentalagus furnessi is a rare forest-dwelling form endemic to the Amami and Tokuno Islands in Japan. In order to estimate the distribution and abundance of the Amami rabbit we counted their faecal pellets along forest roads and streams as well as within the forests on Amami and Tokuno Islands during January 1993–March 1995. The number of pellets/ km along a stream gave a practical index for measuring relative abundance. The rabbit was estimated to be distributed over about 370 sq km on Amami Island and 33 sq km on Tokuno Island. There was a large variance in faecal abundance among the survey routes. Some populations were completely isolated and thought to be very small. The size of a local population was positively correlated with those of neighbouring populations and the amount of mature forest relative to other serai stages. We compared the results of this survey with those of previous surveys to find that the total population of this species appears to be declining. Some conservation measures are proposed for forest habitat management, designed to avert the decline of the Amami rabbit and to ensure its preservation.

Abstract: Context There has been concern that feral cats have negative impacts on the endangered endemic mammals of Amami-Ohshima Island, Japan, including the Amami rabbit, Pentalagus furnessi, Ryukyu long-tailed giant rat, Diplothrix legata, and Amami spiny rat, Tokudaia osimensis. However, no diet study of feral cat has been conducted to support the necessity of an urgent feasible feral-cat management for the island. Aims The aims of the present study were to analyse feral-cat diet on Amami-Ohshima Island by using scat analysis and estimate the potential predation impact of feral cats on endangered mammals on the island. Methods The diet of feral cats was studied using scat analysis. We estimated the number of prey, percentage of prey, frequency of occurrence (the percentage of scats in a sample containing a particular prey item), percentage of biomass (biomass of the same prey item divided by the total consumed biomass ×100) and daily consumed biomass (DCB). Key results Three endangered endemic mammals were the main prey species of the feral cat diet (65% of total DCB). The percentage contributions of these species on DCB were long-tailed giant rat (34.7%), Amami spiny rat (21.9%) and Amami rabbit (12%). Conclusions Mammals, especially endangered endemic mammals, were main prey species of feral cat on Amami Island. In Amami Island, where native and invasive rodents coexisted, feral cats consumed more native (56.6%) than invasive (22.2% for Rattus rattus) species. Implications Feral cats are likely to be having a significant impact on endangered endemic mammals on the island. To ensure the long-term survival of these endemic species, active management of the feral-cat population should be considered.

Abstract: The Amami rabbit Pentalagus [urnessi is an endemic species of the central Ryukyus, Japan, and occurs only on two islands, Amami Oshima I. and Tokunoshima I. For the conservation of this species, some research programs to reveal the population size, spatial and temporal patterns of activity, and impacts of introduced predators were carried out. The habitat available to the rabbit has obviously been reducing with considerable fragmentation on each island, and size of each population also seems to have been decreasing as well (2700-6500 in total of the two islands in 1995). The estimated home range size was relatively small (1.3 ha for males and 1.2 ha for females), and the rabbits moved 100-200 m from their burrows mainly during the night. The negative impact of the introduced mongoose on the rabbit was quite serious on Amami Oshima I., and effective control of this exotic predator is an urgent necessity for the conservation of the rabbit, as well as the whole ecosystem, of this island.