Details of this species in Amami Is. Status: Alien
Invasiveness: Invasive
Occurrence: Present/controlled
Source: Yamada, 2002. Arrival Date: 1979
Introduction: Intentional Species Notes for this Location:
Thirty small Indian mongooses (Herpestes javanicus) are believed to have been released
to control the venomous habu snake (Trimeresurus flavoviridis) and the black rat (Rattus rattus)
in 1979. Since then, the mongoose has been expanding
its distribution from the release site, covering a
10 km radius by 1989 and a 20 km radius by 1997, covering
half of mountainous areas occupied by many threatened
species, such as the Amami rabbit (Pentalagus
furnessi). The rate of range extension was estimated as
1 km per year. After 20 years the population size was
estimated at 5000-10,000 mongooses in 1999. Management Notes for this Location:
The local government began to trap the mongoose in order to reduce crop damage
in farmlands around the city from 1993 and the Yamato Village Office also began trapping from 1995. As many as 1100-1500 mongooses were captured by 15-20 trappers
using 10-30 traps per person for seven to nine months
(May-March) in a year. Approximately 60-80%
of those mongooses were captured by four to five skilful
trappers.
The Environment
Agency of the Central Government carried out preliminary
investigations during 1996-1999 into the possibility
of eradicating mongooses from the whole island. Following on from the pilot investigations, the Environment Agency decided to begin a full-scale project to eradicate
the mongoose from the whole island from 2000 by
two methods: (1) great reduction of population using many
traps during a short period (3 years) over the whole island
(the annual target reduction was 4000-5000, including the
number by pest control around farmland by the local governments
during May to March, and by trapping in mountainous
areas by the Environment Agency during October
to March), and (2) long-term eradication until the species
becomes extinct.
A total of 3886 mongooses were captured by trapping, but
the number was lower (87%) than the target number (4500)
in the first year (fiscal 2000). The catch comprised 1073
animals by pest control and 2813 by the eradication project
of the Environment Agency. Location Notes:
Amami Island is 710 km 2 in area and 694 m in maximum elevation, and 70% of the island is covered by forest. The island, one of the small islands of the Ryukyu Archipelago in the most south-western part of Japan, has many endemic
and threatened species. Impacts:
Agricultural: The small Indian mongoose (Herpestes javanicus) has a large impact on crops (taro, sweet potato, melon, watermelon, loquat, etc.) and poultry in
farmland. The economic cost of the damage rapidly in-creased
in 1994 (USD7000), 1995 (USD32,000), 1996
(USD64,000), 1997 (USD110,000), 1998 (USD100,000)
and 1999 (USD80,000).
Predation: The small Indian mongoose (Herpestes javanicus) has had a predatory impact on native animals in the mountainous areas of the island where it has advanced since 1986. Threatened native species that have been recorded in the diet of the mongoose include: 'Endangered' Ryukyu rat (seeDiplothrix legatus), the Ryukyu spiny rat (see Tokudaia osimensis), Amami rabbit (see Pentalagus furnessi); the 'Endangered' Ryukyu woodcock (see Scolopax mira; the 'Vulnerable' Amami jay (see Garrulus lidthi), 'Near threatened' Ryukyu robin (Erithacus komadori) In IUCN Red List of Threatened Species; reptiles Japalura polygonata, Barbour's Eyelid Skink (Eumeces barbouri), Calliophis japonicus japonicus and Cyclophiops semicarinatus; and the mammal Crocidura horsfieldii watasei (Yamada, 2002). Last Modified: 26/04/2004 2:04:19 p.m.
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