墾丁野生梅花鹿（Cervus nippon）之鹿群組成變化

鹿科動物的群聚結構會受到生殖週期的影響，而使鹿群組成產生月份上的差異。墾丁國家公園自1984年進行台灣梅花鹿(Cervus nippon taiouanus)之復育，目前已形成穩定的野生族群。本研究為首次紀錄台灣梅花鹿在自然狀況下鹿群組成在月份上的波動，及其與生殖週期之間的關聯。本研究於2016年10月到2018年3月間，在墾丁水蛙窟大草原以空拍機紀錄鹿群的組成；同時，本報告也分析另一組團隊在森林環境(墾丁高位珊瑚礁自然保留區)內的自動相機資料，估計幼鹿的幼母鹿比及亞成體比率。空拍機結果顯示：鹿群的群體大小在月間並沒有顯著的差異變化，但鹿群組成在發情高峰期（10-12月）及非發情高峰期間，則有顯著差異。單隻公鹿出現機率最高的季節是10月-12月(佔公鹿群的75.5-90.3 %)。公母混群的性別比例方面，在4-8月偏雄性(61.7-74.1%)、10-12月則偏雌性(68.0-75.3%)。這些月間的變化與梅花鹿的發情和生產的季節現象相吻合。草原環境的幼母鹿比(10月每百隻成年母鹿的幼鹿數)在2016年為51.5%、2017年為63.7%，亞成體比率(7月每百隻成年母鹿的1歲及2歲亞成體數)分別為44.2%以及30.8%。森林環境的幼母鹿比(11月每百隻成年母鹿的幼鹿數)在2016、2017兩年均為66.5%，亞成體比率(7月每百隻成年母鹿的1歲及2歲亞成體數)則分別為45.1%以及33.8%。前述各項族群生態學的參數，可提供墾丁梅花鹿復育族群數量動態變化及族群未來的發展模擬之依據。

關鍵字

自動照相機；空拍機；幼母鹿比；性別比；墾丁國家公園

並列摘要

The herd composition of Cervids is influenced by breeding cycle, and therefore differs in month. Formosan sika deer (Cervus nippon taiouanus) had been re-introduced by Kenting National Park since 1984. A stable wild population has been formed. The present study recorded, the first time in the history, their monthly herd composition change under natural condition and discussed its relation with breeding cycle. Drone was used to record the deer herd composition in the Shuiwaku area (grassland habitat) from October 2016 to March 2018. Fawn-doe ratio and young-doe ratio based on data collected, during the same period, by camera trappers in the Nature Reserve of Uplifted Coral Reef (forest habitat), by another research team, were also analyzed. The results from the drone filming show that there is no difference in average group size (≧2 individuals) among different months. However, the herd composition is significantly difference between the peak of rutting season (October-December) and the rest of the year. Males in single are most likely to exist during October to December (75.5-90.3%) in all male groups observed). For the mixed group, the composition were clearly male-bias (61.7%-74.1%) from April to August, while they were female-bias (68.0-75.3%) from October to December. These seasonal changes match the timing of mating and birth season. The fawn-doe ratio on grassland habitat in October were 51.5% in 2016 and 63.7% in 2017. The young ratio of 1 year and 2 years old young to doe in July were 44.2% and 30.8% respectively. The fawn-doe ratio (in November) in the forest habitat were 66.5% in both 2016 and 2017. The young-doe ratio of 1 year and 2 years old young in July were 45.1% and 33.8% respectively. These population parameters for the re-introduced sika deer population in Kenting should be helpful in predicting the future development of the population.