擎天崗水牛的族群親緣、季節群聚與永續經營

The Phylogenetic Relatedness, Seasonal Activities and Sustainable Management of Water Buffalo (Bubalus bulalis) in Qingtiangang

胡正恆(Hu, Chengheng)

《華岡農科學報》 48期 (2021/12) Pp. 45-66

摘要

本研究探討擎天崗野化水牛（Bubalus bulalis）與極端氣候下的生態互動過程。擎天崗自上個世紀以來，水牛在森林間塑造草原與濕地的鑲嵌棲地。除了消耗草／灌木為食外，水牛還通過穿越茂密灌叢、和淺掘水洞來影響植被。水牛生態調查自2020年1月至2021年12月，每月以軌跡紀錄器追蹤水牛族群，觀察所在林區之覓食偏好，並收集野外動物季節成長與生理體質的資料。結果發現擎天崗水牛具特殊的遺傳資源：粒線體DNA（mtDNA）分析顯示控制區（D-Loop）和色素胞（Cytb）具含有顯著遺傳多樣性，並非近親繁殖群。水牛春夏生長季在高日照下群集泥浴，秋冬則每週長程縱走、擴大搜食：一整年穿戴GPS所得軌跡於節電模式下，每日有百處以上之六分鐘定位點，足以判讀群聚空間的特性。春季具彈性活動範圍，長程遊走覓食活動範圍可達16.7 ±7.4 ha；夏季因群聚泡水活動範圍縮小至9.6 ± 3.6 ha，屬高度群聚的戀地狀態，白天絕大時候都在泥浴。秋季成群遷移則反應出多變氣候狀態下的植生限制，長程覓食而不常待在擎天崗草原；冬季能定位的座標銳減，因每週活動範圍廣及150～350 ha之大，牛會進入人跡罕至的背風溪谷尋求育幼與越冬庇護。曾於2020年記錄到越冬不順利的母牛，在秋末兩個月內體質流失達29.3±11.5%（n=3）而衰弱死亡。總結水牛與水鹿及山羌在嚴苛生態因素限制下，為共同維護林下植被的生態功能群，在亞熱帶闊葉林下尤其值得永續其生態功能與關鍵棲地。

關鍵字

水牛（Bubalus bulalis） ； 擎天崗 ； 粒線體DNA ； 文化動物 ； 生態功能

並列摘要

This study explores the ecological interaction between the feral buffalo (Bubalus bulalis) and extreme climate changes in Qingtiangang. Since the last century, buffalo has played a unique role in shaping the mosaic grassland across forest habitats. While consuming grass/shrubs for daily food staples, buffaloes also influence vegetation by crossing bushes and creating temporary water holes. From January 2020 to December 2021, the Qingtiangang buffaloes were tracked with a GPS recorder every month to observe their foraging preferences, and to collect body information on seasonal growth. The results found that Qingtiangang buffalo has special genetic resources: mitochondrial DNA (mtDNA) analysis shows that the control region (D-Loop) and cytochrome (Cytb) have significant genetic diversity, indicating that they are not inbreeding herds. During the spring and summer, buffaloes gather in water holes under high sunshine, and in autumn and winter, they walk long distances every week to forage. A collared GPS of wild buffaloes obtained more than 100 locating points every day in 2021. Daily home range in spring (16.7±7.4 ha) can be reduced to 9.6±3.6 ha in summer due to mud bath. In autumn, buffaloes migrated for diverse vegetation under the changing climate, less seen in Qingtiangang grassland. In winter, weekly home range can peak up to 150~350 ha, entering the leeward valley to seek over-wintering refuge. In 2020, cows that had a physical loss of 29.3±11.5% (n=3) died of weakness in the last two months of autumn. To summarize, the buffalo's flexible ranges of seasonal activities reflect the changing vegetation under extreme climatic conditions. Water buffalo, sambar and munjac are impacted by severe ecological factors. To sustain the ecological functioning of foraging understory vegetation, it is important to maintain key habitats of feeding and over-wintering in the subtropical broadleaf forest.

並列關鍵字

Water Buffalo (Bubalus bulalis) ； Qingtiangang ； mitochondrial DNA (mtDNA) ； cultural animals ； ecological functioning