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 1
Ryukyu Archipelago - one of biodiversity hot spots of the world Kagoshima Tokyo Amami-oshima Island (712 km 2 ) Population: 70,000 Amami-oshima Okinawa Taiwan Okinawa Island (1,208 km 2 ) Population: 1,200,000 2
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 Korea Watase line Kyusyu Taiwan Islands of poisonous snake, habu 3
Native wildlife in the Ryukyus evolved in the absence of predatory mammals Iriomote cat (Prionailurus bengalensis iriomotensis) Crested Serpent Eagle (Spilornis cheela perplexus) Okinawa-group Yaeyama-group Miyako-group Miyako Is. Iriomote Is. Ishigaki Is. Amami-group Amami-oshima Is. Tokunoshima Is. Okinawa Is. Amami rabbit (Pentalagus furnessi) Amami woodcock (Scolopax mira) Okinawa woodpecker (Dendrocopos noguchii) Okinawa rail (Gallirallus okinawae) Yambaru long-armed scarab beetle (Cheirotonus jambar) Amami thrush (Zoothera dauma major) 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. Small Indian mongoose 100 of the worst invasive alien species by ISSG, IUCN 5
More than 70 islands/areas introduced (Hays & Conant, 2007) 6
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 of 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 (2004 2004 年 ) (1978 1978 年 ) 1990 O kinaw a Is. (1,206km 2 ) released in 1910 (300km 2 ) 7
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. SF line FY 2000 FY 2003 FY 2006 8
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. Live trap Forest work Kill trap Sensor cameras Sniffer dogs Native species monitoring 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 9
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 Amami spiny rat (Tokudaia osimensis) Ryukyu longhaired rat (Diplothrix legata) trigger Okinawa rail Simulation and trial to decide trap shape for preventing endemic birds Amami 10 jay
Changes in capture status Distribution of mongooses have decreased Capture number of mongooses Capture number of mongooses Capture number of mongooses Capture number of mongooses 2006 2007 2008 2009 Location of trap installation Location of trap installation Location of trap installation Location of trap installation Capture number of mongooses Capture number of mongooses Capture number of mongooses 2010 2011 2012 Location of trap installation Location of trap installation Location of trap installation 11
Changes in capture status Mongooses have steadily decreased 1,000 800 600 400 200 208 284 520 543 Mongooses Trap-days 619 573 549 560 396 230 255 202 2,500,000 2,000,000 1,500,000 1,000,000 500,000 0.500 0.400 0.300 0.200 0.100 0.16 0.27 0.43 0.29 0.20 CPUE(Mongooses/100Trap-days) (C/100TD) 0.19 0.17 0.06 0.03 Okinawa 0.02 0.016 0.014 0 0 0.000 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. 12
1979: Introduction into Amami from Okinawa Island 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 released in 1979 (1990 年 ) (2004 年 ) (2004 年 ) A m am i-oshim a Is. (712 km 2 ) 14
Strong negative impacts on native vertebrates Partial extinction of mammals and amphibians in range of mongooses :distribution of native vertebrates :core area of range of mongooses Amami rabbit Amami Ishikawa s frog Ryukyu long-haired rat Otton frog Amami spiny rat Amami tip-nosed frog Amami Wildlife Conservation Center from 2000 to 2006 15
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 CAmami city 16
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 km 2 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 120 100 80 Seminar for bounty trapper Live trap Bounty trapper Full time trapper 60 40 20 0 12 1 4 6 17 2000 2001 2002 2003 2004 2005
2005- Organizing Amami Mongoose Busters (AMB) 120 100 80 60 40 20 0 Invasive Alien Species Act was enforced in 2005 MOE launched a mongoose eradication project, hiring trapping experts, Amami Mongoose Busters (AMB). Bounty trapper Full time trapper, AMB 18
2013: AMB and trained sniffer dogs 19
1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 32,357 mongooses caught in 20 years 4,500 4,000 3,500 3,000 Project by MOE Pest control Trapping data set AMB 2,500 2,000 1,500 1,000 500 0 10,351 mongooses by pest control 22,006 mongooses by MOE project 20
CPUE (Capture/1000trap-days) distribution FY2001 21
CPUE (Capture/1000trap-days) distribution 2001 2002 2003 2004 2005 2006 2007 2008 2009 22
Log_CPUE (C/1000TD) 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2010 2011 2012 100.00 10.00 1.00 0.10 0.01 Year 23
In 37,000 FY2012, traps 179 are mongooses deployed were caught with 2.26 million trap-days. 18 mongooses were caught with sniffer dogs and handler. Live trap Kill trap Modified kill trap FY2012: 197 mongooses captured 24
Log 10 (Population size) 個体数 100 1000 10000 Abundance dynamics of mongooses Estimated 推定個体数 population Number 捕獲数 of capture Hierarchical Bayes Model 1980 1990 2000 2010 year 25
10 15 CPUE(animals /1000trap-days) 0 5 1 10 2 0 1 2 0 5 10 15 0 5 10 15 0 5 10 0 5 10 (B) Black rat Recovery of native species 1 Fukasawa et al., 2013a Proc. R. Soc. B Alien (A) (C) Amami Small Indian Spiny mongoose rat Native (C) Amami Spiny rat (B) (D) Black Ryukyu ratlong-haired rat (D) Ryukyu long-haired rat 2002 (C) Amami 2004 Spiny 2006rat 2008 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. Year 2002 2004 2006 2008 26
Recovery of native species 2 Watari et al., 2013 Ecology and Evolution Scientists surveyed the population densities along logging road of four endangered species threatened by the mongoose. Amami rabbit Amami tipnosed frog Otton frog Amami Ishikawa s frog Figure 3. Temporal changes in numbers of four species observed per site per survey (mean SE). 27
Probability of eradication success 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. Fukasawa et al., 2013b J. Applied Ecology 1.0 0.8 0.6 0.4 0.2 0.0 7.0 6.5 6.0 5.5 5.0 4.5 2020 2050 2040 2030 The eradication feasibility of mongooses was estimated using trapping data. (see black circle which indicate eradication feasibility.) 0.0 0.2 0.4 0.6 0.8 1.0 28
Eradication action plan by 2022 New ten year mongoose eradication plan was settled on from FY2013 to 2022. The challenges are to eradicate small number of 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. Monitoring area Priority area http://kyushu.env.go.jp/naha/wildlife/data/gairai/boujyo/130425b.html 29
Education & Awareness Pamphlet for the mongoose eradication measure http://kyushu.env.go.jp/naha/wildlife/data/gairai/boujyo/131017a.pdf 30
Thank you for your attention 31