mongooses in Japan - Okinawa and Amami-oshima Island- Office for - - PowerPoint PPT Presentation

Eradication project of invasive alien mongooses in Japan

• Okinawa and Amami-oshima Island-

Office for Alien Species Management, Wildlife Division, Nature Conservation Bureau, Ministry of the environment

Masato Morikawa

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Okinawa Amami-oshima Tokyo Kagoshima Taiwan

Okinawa Island (1,208 km2) Population: 1,200,000 Amami-oshima Island (712 km2) Population: 70,000

Ryukyu Archipelago

• one of biodiversity hot spots of the world

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Ryukyu Archipelago

• one of biodiversity hot spots of the world
• Biogeographically, border of Palearctic and Oriental region.
• Isolated from the continent about 2 - 1.7 million years ago.

c.f. Mainland Japan : isolated about 10 000 – 20 000 years ago.

• Many endemic species inhabit with limited predator species

Kyusyu Korea Taiwan Watase line

Islands of poisonous snake, habu

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Amami-group Okinawa-group Miyako-group Yaeyama-group

Iriomote Is. Ishigaki Is. Miyako Is. Okinawa Is. Amami-oshima Is. Tokunoshima Is.

Native wildlife in the Ryukyus evolved in the absence of predatory mammals

Amami rabbit (Pentalagus furnessi) Amami woodcock (Scolopax mira) Amami thrush (Zoothera dauma major) Okinawa rail (Gallirallus okinawae) Yambaru long-armed scarab beetle (Cheirotonus jambar) Okinawa woodpecker (Dendrocopos noguchii) Iriomote cat (Prionailurus bengalensis iriomotensis) Crested Serpent Eagle (Spilornis cheela perplexus) 4

Small Indian Mongoose

(Herpestes auropunctatus)

• A small, slim-bodied predator native

to areas from Iran, through India to Myanmar, VietNam.

• It has been introduced to many

islands to control rats, particularly in sugar cane fields of tropics.

• The mongoose has had a major

impact on native species in the areas where it has been introduced.

100 of the worst invasive alien species by ISSG, IUCN

Small Indian mongoose

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More than 70 islands/areas introduced

(Hays & Conant, 2007)

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rel eased i n 1910 （ 1978年） （ 2004年）

O ki naw aw a a I s.

1910: First introduction to Japan

• Dr. Watase, the famous biologist

in Japan was advised by foreign scientists to import mongooses to control poisonous snake Habu and harmful black rat

• Released around southern part
• f Okinawa and settled and

spread gradually

• 1990s: Expand to Yamabaru

region(northern Okinawa) , the hotspot of wildlife

• Mongoose Control measure

launched by Okinawa Prefectural Government & MOE launched from 2000

(1,206km2)

1990 1978 2004

(300km2)

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Starting control efforts

• In 2000, the Okinawa Prefectural Government began cull efforts.
• In 2005, control efforts began with the enforcement of

the Invasive Alien Species Act.

• The mongoose population continued to expand until 2006, causing the

Okinawa rail population to retreat.

• Mongoose proof fence installed in 2006 in SF line to prevent mongooses

from spreading north.

FY 2003 FY 2000 FY 2006

8 SF line

Outline of control measures

• Control initiatives began with cage-type live traps, which required daily
• checking. Trappers installed traps along logging roads.
• The introduction of tube-type kill traps for which checking frequency can

be set as desired (usually every two to four weeks) and the use of kill traps and live traps as required brought about a drastic increase in the number of traps managed.

• Trappers began related work in forests in FY 2007.

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2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 Live trap Forest work Kill trap Sensor cameras Sniffer dogs Native species monitoring

Preventing damage of indiscriminate capture

• Kill traps were first introduced in 2003
• Deploy endemic rats are absent and/or

in low density.

■ Live trap …Everyday checking is necessary …Used in habitat of endangered native species ■ Kill trap (Pipe- trap) …Efficient (Lightweight, Set for 2-4 weeks) …Birds : discriminable Rats : indiscriminable

Simulation and trial to decide trap shape for preventing endemic birds

Ryukyu long- haired rat （Diplothrix legata） Amami spiny rat （Tokudaia

• simensis）

Amami jay 10 Okinawa rail

trigger

Changes in capture status

Distribution of mongooses have decreased

2006 2007 2008 2009

Location of trap installation Location of trap installation Location of trap installation Location of trap installation

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2010 2011 2012

Location of trap installation Location of trap installation Location of trap installation Capture number of mongooses Capture number of mongooses Capture number of mongooses Capture number of mongooses Capture number of mongooses Capture number of mongooses Capture number of mongooses

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208 284 520 543 573 549 619 560 396 230 255 202

500,000 1,000,000 1,500,000 2,000,000 2,500,000 200 400 600 800 1,000 Mongooses Trap-days

0.16 0.27 0.43 0.29 0.20 0.19 0.17 0.06 0.03 0.02 0.016 0.014

0.000 0.100 0.200 0.300 0.400 0.500 CPUE (C/100TD)

Okinawa

CPUE(Mongooses/100Trap-days)

• Since the Yambaru Mongoose Busters started its activities, there has been a

drastic increase in the total number of traps (see the line graph). The total number of trap days has kept around 1.5 million every year since 2011. The number of mongooses caught (see the bar graph) has shown a declining trend since 2008, and been a significant drop in the number in recent years.

• CPUE, an indicator of mongoose population size, has continued to decrease.

Changes in capture status

Mongooses have steadily decreased

1979: Introduction into Amami from Okinawa Island

rel eased i n 1979 （ 2004年） （ 1990年）

A m am am i

• oshi

m a a I s.

（ 2004年）

(712 km2)

• There are few records about

introduction into Amami

• Mongooses were brought in from

Okinawa Island (Sekiguchi et.al.,2001)

• Mongooses successfully settled on

Amami and expanded their distribution

• Damages on farming and poultry

gradually appeared from 1983

• Some research by Amami

Mammalogical Society from 1989

• Pest control by local government

began from 1993

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Strong negative impacts on native vertebrates

Partial extinction of mammals and amphibians in range of mongooses

Amami Wildlife Conservation Center from 2000 to 2006

Amami rabbit Ryukyu long-haired rat Amami spiny rat Amami Ishikawa s frog Otton frog Amami tip-nosed frog 15

：distribution of native vertebrates ：core area of range of mongooses

1993-: Pest control by local government

• Pest animal that causes harm to crops

and chicks

• Local government launched control to

reduce damages of crops

• Licensed trapper were paid JPY 2,200

for a mongoose

• 8,234 mongooses were captured in

seven years (1993-1999)

• Most of them captured around the

center of distribution, high density area

ⒸAmami city

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2000-2004: Control program by bounty trapper

• At the beginning, mongooses were live trapped

by one hundred bounty trappers

• To keep incentive to trap, bounty increased

from JPY 2,200 (2000) to JPY 4,000 (2001-02) and JPY 5,000 (2003-04)

• Trapping data of bounty trappers were

collected with using standard grid square (about 1 km2 mesh)

• A small number of trappers were employed to

set traps at low density area and in bushes. 1 trapper in 2002, 4 in 2003, and 6 in 2004

• 14,558 mongooses were caught in this five

year trapping 2000-2004

Seminar for bounty trapper Live trap

1 4 6 12 20 40 60 80 100 120 2000 2001 2002 2003 2004 2005

Bounty trapper Full time trapper 17

2005- Organizing Amami Mongoose Busters (AMB)

• Invasive Alien Species Act was enforced in 2005
• MOE launched a mongoose eradication project,

hiring trapping experts, “Amami Mongoose Busters (AMB)”.

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20 40 60 80 100 120 Bounty trapper Full time trapper, AMB

2013: AMB and trained sniffer dogs

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32,357 mongooses caught in 20 years

20 500 1,000 1,500 2,000 2,500 3,000 3,500 4,000 4,500 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 Project by MOE Pest control

10,351 mongooses by pest control 22,006 mongooses by MOE project Trapping data set AMB

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CPUE (Capture/1000trap-days) distribution FY2001

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2001 2002 2003 2004 2005 2006 2007 2008 2009 CPUE (Capture/1000trap-days) distribution

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2010 2011 2012

0.01 0.10 1.00 10.00 100.00 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012

Log_CPUE (C/1000TD) Year

Live trap Kill trap Modified kill trap

37,000 traps are deployed

FY2012: 197 mongooses captured

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In FY2012, 179 mongooses were caught with 2.26 million trap-days. 18 mongooses were caught with sniffer dogs and handler. In FY2012, 179 mongooses were caught with 2.26 million trap-days. 18 mongooses were caught with sniffer dogs and handler.

1980 1990 2000 2010 個体数 100 1000

推定個体数 捕獲数

10000 Log10 (Population size) year

Estimated population Number of capture

Abundance dynamics of mongooses

Hierarchical Bayes Model

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Fukasawa et al., 2013a

• Proc. R. Soc. B

Year CPUE(animals /1000trap-days)

5 10 15 (A) Small Indian mongoose 5 10 (B) Black rat (C) Amami Spiny rat 5 10 15 (C) Amami Spiny rat 2002 2004 2006 2008 1 2 (D) Ryukyu long-haired rat 2002 2004 2006 2008

Recovery of native species 1

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Alien Native

Figure 2. Temporal changes in catch per unit effort . For the rat species, the solid and dashed lines indicate the areas of mild (habitat alteration index, HAI<0) and intensive (HAI >0) habitat alteration, respectively.

Watari et al., 2013 Ecology and Evolution

Recovery of native species 2

Scientists surveyed the population densities along logging road of four endangered species threatened by the mongoose.

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Amami rabbit Amami tip- nosed frog Otton frog Amami Ishikawa’s frog

Figure 3. Temporal changes in numbers of four species

• bserved per site per survey (mean SE).

Fukasawa et al., 2013b

• J. Applied Ecology

Probability of eradication success

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• This simulation shows the current capture efforts of 2010 is the most

cost-effective way to eradicate mongooses in this island. The eradication success might be feasible if eradication action same capture efforts of 2010 is continued over the next decade.

• However, we think that the most difficult point of eradication of

mongooses is one final push (Trapping final 10 mongooses ). Therefore we are also considering alternative measure.

― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ―

0.0 0.2 0.4 0.6 0.8 1.0

2020 2030 2040 2050 4.5 5.0 5.5 6.0 6.5 7.0 0.0 0.2 0.4 0.6 0.8 1.0

The eradication feasibility of mongooses was estimated using trapping data. (see black circle which indicate eradication feasibility.)

• New ten year mongoose

eradication plan was settled on from FY2013 to 2022.

• The challenges are to

eradicate small number

• f mongooses scattered

in a large area, and to ensure that no mongoose survives in every area, with using sniffer dogs, camera traps and hair traps.

Eradication action plan by 2022

Monitoring area Priority area

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http://kyushu.env.go.jp/naha/wildlife/data/gairai/boujyo/130425b.html

Education & Awareness

Pamphlet for the mongoose eradication measure

http://kyushu.env.go.jp/naha/wildlife/data/gairai/boujyo/131017a.pdf

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Thank you for your attention

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