1 A risk management model for deer population in the Yakushima World Natural Heritage H Matsuda*, A Ohta, S Tatsuzawa, H Takahashi, K Tokida, * News I am looking for 11 postdocs of a JSPS grant: Global Eco-Risk Management from Asian Viewpoints (

2 Aims of this research Sika deer Cervus nippon yakushimae (endemic subspecies) damages on natural vegetation and endemic plants A population dynamic model to propose a management plan

3 What areas should we protect? Areas that include many rare plants high vegetation damage by deer –Logging roads may enhance deer dispersal and outbreak throughout the island Areas that include many rare plants without heavily vegetation damage –Few chance of dispersal and high hunting pressure From Tet Yahara’s idea 2007/8/7

4 ＜ 1000 deer? GPS points of deer by spotlight count (2005) 一湊 永田 大川林道 小楊子林道 栗生 モッチョム農道 安房林道 荒川林道 白谷線 宮之浦 安房線 安房 長峰 小瀬田 中間林道 小瀬田林道 船行農道 湯泊林道中瀬川林道 尾の間 deer? deer? Northeastern zone Southern zone Western zone Data obtained & compiled by Tatsuzawa & Takahashi 2007/8/7

5 Increase of spotlight counts of deer (Tatsuzawa & Takahashi, unpubl. data) 0.33 → 0.92 deer/km, from 1995 to 2005 Deer is overabundant in Western zone and Northeastern zone Deer is relatively fewer in Southern zone /8/7

6 The number of removal just 300 removal in Yakushima Island Kamiyaku Town Yaku Town Kagoshima Pref. & Serow Tatsuzawa 4 Islands in Kagoshim Pref. 2007/8/7 Kamiyaku Town Yaku Town

7 Agricultural damage by wildlife in Yakushima Island Yakushima cho Monkey Deer } Birds Damage (thousand yen) 2007/8/7

8 ＜ 1000 deer? Northeastern zone Southern zone Western zone Zone-dependent deer management plan 2007/8/7 1) deer? 2)>300 s 3)Depends on hunting effort 1) deer? 2)We need to hunt > s 3)We give up to control! 1) deer? 2)We need to hunt > s 3)We give up to control! 1)<1000 deer? 2) s 3)We try to decrease deer

9 Zoning plan Northeastern zone Southern zone Western zone ■ National forest ■ Deforested area ■ Orchard Serow Tatsuzawa 一湊 永田 大川林道 小楊子林道 栗生 モッチョム農道 安房林道 荒川林道 白谷線 安房線 安房 長峰 小瀬田 中間林道 小瀬田林道 船行農道 湯泊林道中瀬川林道 尾の間 Aiko-dake Protected zone World heritage area (107km 2 ) 1) deer? 2)>300 s 3)Depends on hunting effort 1)<1000 deer? 2) s 3)We try to decrease deer 2007/8/7 1) deer? 2)We need to hunt > s 3)We give up to control! 1) deer? 2)We need to hunt > s 3)We give up to control!

10 A population dynamic model 3 habitat model with environmental stochasticity # 0 year old # adult femals # adult males Repro. Success. R(t) Recruit from 0 yr oldAdult survivalCatch Survival rate S

11 Adaptive catch quotas Hunting effort depends on the monitored population index Pop. level North- east zone Southern zone Hunting % α Catch limit

12 Results when catch limit = 1000 Year after present NorthEast & South 95%CI >30% decline is expected We might catch ca deer for >10 yrs Population index N(t)/N(0) Catch in number

13 3 monitoring site plan Northeastern zone Southern zone Western zone Aiko-dake Mountain & catchment Onoaida pathway Seibu-rindo logging road 2007/8/7

14 Aiko-dake Mountain Protection Area plan Villages including Onna- gawa riv. Catchment River boundary! Monitor Catch statistics of female deer Estimate deer population size 2007/8/7

Why do we use river boundaries? Deer dispersal is often limit by rivers. Villages are usually divided by rivers. Catch statistics by hunters are easily compiled by areas between rivers Therefore, a region between rivers is used as a relatively isolated deer habitat /8/7

16 Intensive Monitoring of Ono-aida path plan Villages between Taino-kawa Riv and Suzu- kawa Riv. Monitor Vegetation and Plant Species Monitor Catch Statistics of 9 Female Deer Estimate Deer Population Size 2007/8/7

17 Seibu-rindo logging road monitoring site Business as usual Monitor natural increase of deer by spotlight count and density estimation. Monitor damage on natural vegetation Monitor endemic threatened plant species. 2007/8/7

18 Monitoring deer population Sex, stage, zone-dependent Catch statistics Catch per unit effort (hunter sampling) –Catch position (GPS), time, sex (CPUE in national forest) Spotlight count along routes and logging roads Altitude-dependence in deer density –Automatic monitoring by night vision; –Line transect survey along Anbo-rindo logging road, Onoaida path, Aiko-dake Mountain Prot. Area 2007/8/7

19 Management plan Test effect of deer on natural vegetation –Vegetation recovery survey inside of fence Reducing agroforest damage –Hearing of farmers and citizens –Improving population dynamic model Promoting sustainable use of deer meet 1000 catch is short for the Western Zone. 2007/8/7

20 Routes of spotlight count (total length 202.9km) 2007/8/7 paved unpaved