Amami Woodcock population quadruples after mongoose eradication
Numbers have risen from about 4,100 to around 17,000 following a long-running programme to remove an invasive predator from the Japanese island of Amami-Oshima.
The population of Amami Woodcock has increased more than fourfold following a sustained programme to remove invasive Small Indian Mongooses from one of the species' most important island strongholds.
Estimates covering three islands in Japan's Amami group, including Amami-Oshima, rose from about 4,100 birds in 2007 to approximately 17,000 in 2021. The striking recovery was recently highlighted by Ornithomedia.
Amami Woodcock is a restricted-range species found only on a small number of islands in the northern Ryukyu archipelago. Larger and longer-legged than Eurasian Woodcock, it inhabits subtropical evergreen forest and feeds mainly at night on the forest floor, where its terrestrial habits leave it particularly vulnerable to introduced mammalian predators.
Around 30 Small Indian Mongooses were released on Amami-Oshima in 1979. The animals had been brought from Okinawa in the hope that they would reduce numbers of the venomous Habu pit viper and introduced rats, but they instead spread across the island and began preying on native wildlife.
By around 2000, the mongoose population was estimated to have reached approximately 10,000. The expanding population coincided with declines in several endemic animals, including Amami Woodcock, Amami Rabbit, Ryukyu Long-haired Rat and a number of rare frogs.
Japan's Ministry of the Environment began an eradication programme in 2000. From 2005, the specialist Amami Mongoose Busters team intensified the work, deploying more than 30,000 traps and over 300 camera traps across forests and other difficult terrain. Detection dogs were also used to locate the last remaining animals.
The final mongoose was captured in April 2018, but intensive surveillance continued for several more years because a lack of captures alone could not prove that eradication had been achieved. Two scientific models eventually calculated eradication probabilities of 99.7% and 98.9%, and the Ministry formally declared the species eradicated from Amami-Oshima in September 2024.
The operation was particularly significant because Amami-Oshima covers about 712 square kilometres, far larger than other islands from which an established mongoose population had previously been removed. The programme lasted around 25 years and involved residents, conservationists, government agencies and specialist field teams.
As mongoose numbers fell, native wildlife began to reclaim parts of the island from which it had disappeared. The range of Amami Woodcock expanded, while monitoring recorded recoveries in Amami Rabbit, Amami Spiny Rat, Ryukyu Long-haired Rat and several endemic amphibians.
The improvement in the woodcock population allowed Japan's Environment Ministry to complete its formal protection and recovery programme for the species in June 2026. The Amami Thrush programme was completed at the same time, marking the first occasion on which Japan had formally concluded one of its national recovery programmes for threatened wildlife following a successful improvement in status.
Both birds were also moved from a threatened category to Near Threatened in Japan's revised national Red List in March 2026. Although the change reflects a major conservation success, continued monitoring will remain important, particularly because feral cats, habitat change, road casualties and the possible arrival of new invasive species still present risks to the islands' endemic wildlife.
The recovery of Amami Woodcock provides a notable demonstration of what sustained invasive-predator control can achieve on a large, inhabited island, while also underlining the ecological damage that can follow the introduction of a non-native predator.
28 Jul 2026
Get Breaking Birdnews First
Get all the latest breaking bird news as it happens,
download BirdAlertPRO
for a 30-day free trial. No payment details required and get exclusive first-time subscriber offers.
Share this story
