玉里野生動物保護區臺灣水鹿(Rusa unicolor swinhoii)棲地利用與密度估算

Habitat Use and Density Estimation of Formosan Sambar (Rusa unicolor swinhoii) in Yuli Wildlife Refuge

林宗以(Chung-Yi Lin)

指導教授 ： 李玲玲

國立臺灣大學/生命科學院/生態學與演化生物學研究所/碩士(2011年)

https://doi.org/10.6342/NTU.2011.02135

摘要

建立大型鹿科動物合適且標準化的密度估算方法，以獲得牠們的密度、變化趨勢，並分析牠們對棲地的選擇模式，為大型鹿科動物經營管理上最迫切需要的資訊。臺灣水鹿為臺灣最大型的草食獸，廣泛棲息於海拔150 ~ 3800 m的山區，然而對於牠們在臺灣的密度及棲地利用模式所知相當有限。本研究於2003 - 2005年以糞堆累積速率計數法透過設置固定寬度的穿越帶，對不同棲地類型進行糞堆密度調查，來估算玉里野生動物保護區臺灣水鹿的族群密度，並以forward stepwise selection複迴歸分析穿越帶的水鹿密度指標與各種棲地因子的關係，來獲得水鹿的棲地利用模式。
2003-2005年玉里野生動物保護區臺灣水鹿的平均密度為10.60隻 / km2 (SE = 2.26隻 / km2)，數量為1210隻（SE = 258隻）。其中位於高海拔的太平谷¬-馬布谷的密度為21.81隻/ km2（SE = 3.76隻 / km2），密度相當高。玉里野生動物保護區周邊地區雄鹿比例顯著較保護區核心區域高，推測這些地區的水鹿族群可能為新近重新再建立的族群。水鹿棲地利用的模式包含4個棲地因子，整體模式達顯著(F4,58= 48.43，p < 0.001)，且解釋了75.3%的密度變異。4個棲地因子分別為是否為森草交界類型（係數為0.157 隻 / ha）、是否為松類森林（係數為0.115隻 / ha）、非玉山箭竹的禾草類覆蓋度（係數為0.171隻 / ha）及樹葉類的物種數（係數為-0.002隻 / ha）等，常數為0.109隻 / ha。4個棲地因子係數都顯著不為0（前二者p < 0.001，後二者p = 0.001）。模式顯示在玉里野生動物保護區，以位於松林與箭竹草原交界的環境、非玉山箭竹的禾草類覆蓋度較高且樹葉類物種數較少的環境，為水鹿利用率最高的環境。本研究顯示玉里野生動物保護區高海拔地區水鹿族群密度相當高，應留意高密度族群對於森林植被更新與演替的效應。同時臺灣水鹿的糞堆分解速率在海拔、植被間差異明顯，進行糞堆計數及以糞堆當作棲地利用指標時，需要納入考量。

關鍵字

臺灣水鹿 ； 糞堆累積速率法 ； 密度估算 ； 棲地使用 ； 性別比例 ； 糞堆分解速率

並列摘要

Standardized method of estimating population density in large cervids provides information for long-term monitoring, habitat use, etc and is urgently needed in the forest management. Formosan sambar (Rusa unicolor swinhoii) is the largest herbivore in Taiwan, which widely inhabits the mountains ranged from 150 to 3800m in elevation; however, the population size and habitat preference of this species is still unclear. We estimated the population density of sambar in Yuli Wildlife Refuge using faecal accumulation rate mothod (FAR) and dung counts with fixed-width strip transect sampling. The habitat use model was then constructed using multiple regression with forward stepwise selection, where habitat characteristics were regressed against density index of sambar.
The average density of sambar in Yuli Wildlife Refuge is 10.6/km2 (SE = 2.26) during 2003-2005 and the population size is around 1,210 (SE = 258). The highest density in the study region is 21.81/ km2 (SE = 3.76) in the Taipin Valley-Mabu Valley. The habitat model explained a significant amount of variation (75.3%), where four habitat characteristics were included (forest-grassland edge, pine forest, non-bamboo grass coverage and diversity of forbs). Sambar prefers the edge of pine forest and bamboo grassland (coefficient: 0.157/ ha, P < 0.001), pine forest (coefficient: 0.115/ ha, P < 0.001), high coverage of non-bamboo grass (coefficient: 0.171/ha, P = 0.001), and low diversity of forbs (coefficient: -0.002/ha, P = 0.001). Our results showed that decomposition rates of Formosan sambar’s dung differed significantly among altitudes and vegetation types, and should be considered when using pellet group count as a measure of habitat use. The high population density of sambar in Yuli Wildlife Refuge can potentially effect on forest renewal and succession and the intense monitoring plan is suggested.

並列關鍵字

Formosan sambar ； Rusa unicolor swinhoii ； faecal accumulation rate ； density estimation ； habitat use ； sex ratio ； faecal decomposition rate.

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