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Biodiversity Conservation
Session 2
Conservation of Threatened Species in Ryukyu Islands toward listing as a World Natural Heritage Site
Noriaki SAKAGUCHINaha Nature Conservation Office, Ministry of the Environment
November 22, 2011
Fauna in Ryukyu Islands and Its Characteristic
Crested Serpent Eagle
Iriomote cat
Ryukyu lomg haired rat
Amami rabbit
Spiny rat
Ishikawa’s frog
Okinawa RailOkinawa woodpecker
About 60 endemic species or subspecies of mammals, birds, reptiles and amphibians in Ryukyu Islands.
Geohistorical Factor Caused Endemic Species
ix) Representing significant ecological and biological processes in the evolution and development of terrestrial ecosystems and communities of plants and animals
x) Containing the most important habitats for in-situ conservation of biological diversity, including threatened species of universal value on science or conservation
Ryukyu Islands Meet Criteria for World Heritage
Most of those endemic species are listed on the Red List, MoE-J
Red List of MoE‐JNo. of endemic species* CR EN VU Total (%)
Mammals 24 6 12 018
(75.0)
Birds 19 4 1 49
(47.4)
Reptiles 43 3 7 1323
(53.5)
Amphibians 20 0 5 49
(45.0)
* including sub‐species
Number of Threatened Species among Endemic Species in Ryukyu Islands
Factors Threatening Endangered Species and Measures for Addressing the Challenges
Factors
Deforestation and Habitat DegradationRoad Kills (Traffic accidents)
Invasive Alien Species
Poaching and illegal tradesChallenges for the designation of the World Heritage
Big Challenges toward World Heritage
1. Eradication of the Mongoose threatening endangered species
Eradication Project of Mongoose
2. Establishment of a protected area to secure endangered species’survival
Identification of important areas, using monitoring research data
In Okinawa Island
Small Indian Mongoose (Herpestes javanicus)One of the 100 of the World's Worst Invasive Species
released in 1910
(1978年)
(2004年)
Okinawa Is.
BW: 0.3 – 1 kg BL: 30 – 40cm TL: 25 – 30cmOriginal Distribution: Malay Peninsula to Middle EastDaily activity: Diurnal Food habits: Omnivorous (mammal, bird, reptiles, frogs
insects, fruits)Law: IAS by Invasive Alien Species Act (2005)Introduction: Ryukyu: Okinawa (1910), Amami (1979)
Other areas: Cuba, West Indies, Fiji, Hawaii
Released in 1910
Okinawa Is.
1978
2004
2000 2003 2006
Expansion of Mongoose Distribution
Impacts on Endangered Species in Yambaru, Okinawa
Distribution of the Okinawa Rail and Mongoose in 2005
Okinawa Rails Mongooses
No. of captured mongooses in each meshConfirmed
UnconfirmedUnsurveyed
South edge of distribution In 1986
2005
Mitigation Plan of the Small Asian Mongoose in the Northern Part of Okinawa Island
drawn up in 2005 in accordance with the IAS Act
Area: Northern part of Okinawa Island (Yambaru), Okinawa PrefectureDuration: April, 2006 – March, 2015Goal: In collaboration with Okinawa prefectural gov.,
MOE-J, in 10 years, completely eradicates the mongooses in the Yambaru., which are causing serious damages on endemic and endangered animals and a subtropical forest ecosystem in the area, and halts the species from re-entry.
Activities: - Intentional Capturing by more than 30 experts and 1 million capturing efforts per year
- Introduction of dogs for searching and capturing - Preventing mongooses from entering the Yambaru by constructing fences
- Monitoring research for evaluation of the project: mongoose and endangered species
The Number of Captured Mongooses by TrappingCa
ptured
Mon
gooses
CPUE (N/100
TD)
Captured Mongooses CPUE
78,576
131,631
105,895
119,734
189,037
279,710298,791
362,553914,842
1,198,282
1,303,149
488,338
20112009 2010200820072005 200620042003200220012000
The number of captured mongooses and its CPUE with trapping efforts (trap days)
Distribution of Captured Mongooses
CPUE (N/100TD) of captured mongooses in each mesh
2008 2009 2010 July, 2011
1‐ 23‐ 56‐1011‐1516‐27
1‐ 23‐ 56‐1011‐1516‐21
1‐ 23‐ 56‐1011‐1516‐22
1‐ 23‐ 5
The number of captured mongooses in each mesh
Challenges to complete eradication of mongoose
The number of Ryukyu longhaired rats bi-catched by trappings has being increasing.
0.000
0.003
0.006
0.009
0.012
0.015
0
40
80
120
160
200
2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010
CPUE(No pe
r 10
0 Traps)
No of captured rats
Death by kill traps Captured and released by live traps
CPUE (number / 100TD)
As mongooses has been decreased, the distribution and number of Ryukyu longhaired rats are expanding and increasing in Yambaru.
Kill trap Live trap
2008 2010
2009
(
3
1
2007
2
Expansion of the Distribution of Ryukyu Longhaired Rat
Adaptive Capturing to Reduce the Bi-catch Risk of the Ryukyu Longhair Rat
FY2008
FY2009
FY2010
The Ryukyu longhaired rat mainly bicatched from December to March.
Using kill traps except in this periodin its higher density areas.
0
50
100
150
200
FY2007 FY2008 FY2009 FY2010
Longhaired rats number
0
20
40
60
80
100
FY2007 FY2008 FY2009 FY2010
1
Mongoose number
0.000
0.100
0.200
0.300
0.400
FY2007 FY2008 FY2009 FY2010
Mongoose CPUE
0.000
0.020
0.040
0.060
0.080
0.100
FY2007 FY2008 FY2009 FY2010
Longhaired rat CPUE
Mongooses are higher density in Area 1. Longhaired rats are higher in Area 2 and lower in Area 1. Mongoose are the lowest and longhaired rats are comparatively high in Area 3.
Kill traps be used in Area 1 through the year and in Area 2 except December – March. Kill traps not be used in Area3.
231‐3
1231‐3
1231‐3
1231‐3
Captured number and CPUE of mongooses and Ryukyu longhaired rats
Number of longhaired rats bicatched
2008
0
2
4
6
8
10
2009
0
5
10
15
20
2010
0
10
20
30
40
50
E LApr
E LJul
E LAug
E LOct
E LNov
E LDec
E LJan
E LFeb
E LMar
E LApr
E LJul
E LAug
E LOct
E LNov
E LDec
E LJan
E LFeb
E LMar
E LApr
E LJul
E LAug
E LOct
E LNov
E LDec
E LJan
E LFeb
E LMar
Identification of Important Areas for Endangered Species
1 2 3 4 5
Ryukyu Longhaired Rat Diplothrix legata ● ●
Ryukyu Spiny Rat Tokudaia muenninki ▲ ●
Okinawa Rail Gallirallus okinawae ● ● ● ●
Okinawa Woodpecker Sapheopipo noguchii ● ●
Ryukyu Robin Erithacus komadori namiyei ● ● ●
Kuroiwa's Ground Gecko Goniurosaurus kuroiwae kuroiwae ● ●
Ryukyu Leaf Turtle Geoemyda japonica ● ●
Ishikawa’s Frog Rana ishikawae ● ●
Okinawa Tip‐nosed Frog Rana narina ● ●
Holst's Frog Rana) holsti ● ●
Surveys conducted for monitoring endangered species
Surveys Data format1. Call back survey on Okinawa Rail by MoE call back number in each 1 km2 mesh2. Call back survey by mongoose project call back number in each 1 km2 mesh
3. Bicatch by Mongoose capturing CPUE (captured number / 100TD)
4. Night rout census by mongoose project Observed number / km in each 1 km mesh
5. Witness information collected by YWCC used for distribution data
Frequency distribution of relative abundance and its grading
0
5
10
15
20
25
30
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
0.45
0.50
0.55
0.60
0.65
0.70
0.75
0.80
0.85
0.90
0.95
1.00
5 for top 10% meshes
1 23
4 Grade
Okinawa Rail
Distribution and Relative Abundance of Four Endangered Species
Ryukyu longhaired Rat Okinawa Rail Okinawa Woodpecker Ryukyu Robin
Identified Important Area in Yambaru
Total score of all 11 endangered speciesIn each mesh
Total species number In each mesh
Toward listing on the World Heritage Sites
We have to concentrate our efforts on
Eradication of invasive alien species
Establishment of protected areas,
Other necessary activities to secure endangered specie’ survival,
in cooperation with researchers and local communities
ご静聴ありがとうございました。
Thank you for your attention!