台灣墾丁地區森林型梅花鹿(Cervus nippon taiouanus)的活動範圍與鹿群組成之研究

物種的族群動態對生態的穩定與平衡具有影響力，物種因應棲息環境會改變其行為和生存策略。自1994年為復育梅花鹿(Cervus nippon taiouanus)族群進行野放後，其族群數量和密度持續上升，為避免族群超過環境乘載量的負荷，瞭解其活動範圍與鹿群組成資訊在日後經營管理上相當重要。本研究於2018至2020年間在墾丁社頂地區利用無線電追蹤六隻個體(兩雄、四雌)，瞭解不同時間區段的活動範圍。本研究發現其95%最小凸多邊形的平均活動範圍為16.3 ± 5.3(3.1-33.8)公頃，不同時間區段(如：乾濕季、生理季節和日夜)皆無顯著差異。另外，使用2015至2017年間的自動照相機資料，於墾丁高位珊瑚礁自然保留區進行性別比、幼/雌鹿比和亞成/雌鹿比的研究。結果顯示在鬱閉度高的森林棲地中，梅花鹿的群體隻數以2-4隻/群為主，其中以雌鹿－小鹿群的觀察紀錄最高。全年族群內性別以雌性個體為主，雄雌比1:2.9；儘管族群密度大，但是性別聚散性指標仍呈現性別隔離的狀況。此外，生育期後期(8-9月)在混合群的性別比大幅增加可能與雌性分娩較為有關。而雄鹿在發情期(10-1月)時，多尖成年雄性會傾向單獨活動，單尖亞成雄性則會有競爭、打鬥、追逐的情況。結果也顯示幼鹿在九月開始出現，而成年雌鹿與幼鹿比在1月後大幅下降，成年雌鹿與亞成鹿比則是全年從1月到12月呈現緩慢下降的趨勢，前述這兩項皆為影響族群結構的重要因素。同時，在比較森林型與草原型棲地的梅花鹿族群差異時，則發現草原型梅花鹿的群體數較大、差異較高。最後，針對梅花鹿族群變動尚有許多影響因素(如，人為干擾、道路分布和流浪犬隻)於本次研究中尚未釐清，建議未來可作為研究方向，以利日後管理策略擬定與相關應用。

關鍵字

自動照相機；瀕危物種復育；高位珊瑚礁；無線電追蹤；社頂；熱帶季風雨林

並列摘要

Population dynamics of species is considered as an influent on stabilities and balances of ecology. Depending on environments, species are likely to change their behaviors and adaptive strategies. After the reintroduction of Formosan Sika deer carried out in 1994, wild population size and density constantly have grown. In order to avoid an overabundance, collecting home range and herd composition information are important for management strategies in the future. From 2018 to 2020, six individuals (two males, four females) were conducted a telemetry study to research the home range of different periods in Kenting Sheding area, Taiwan. Based on radio telemetry results, the average of 95% minimum convex polygon is 16.3 ± 5.3(3.1-33.8) hectares. There were no significant biases from different periods (wet/dry season, physiological season and nocturnal/diurnal period). In addition, camera traps were used to observe male/female ratio, ratios of fawns to adult female and yearlings to adult female of Sika deer in the Kenting Uplifted Coral Reef Nature Reserve from January 2015 to December 2017. The results revealed that the adult female-young groups were the most recorded in our study. In the dense forest habitat, group sizes of sika deer were usually found in small herds(e.g. 2-4 deer/group). The year-round population was female-based. Meanwhile, the overall male and female ratio was 1:2.9. Although population density is high, sexual segregation has still occurred in the dense forest habitats in Sheding area. In August and September, male/female ratios in mixed sex groups were increased, the reason was probably related to female reproductive behavior. During the rutting season, forks were observed more likely to be solitary and spikes demonstrated combative, fighting and chasing behaviors. Besides, the result showed that fawns were observed in September, but the ratio of fawns/100 adult females suddenly declined after January. The ratio of yearlings/100 adult females presented a relaxed downtrend from January to December through the year. Both ratios in previous description are important elements based on herd composition. Considering the different habitat types, a comparison between the entire forest and forest-grassland mosaic habitat of sika deer population had also been made. There were larger group sizes and higher variances in forest-grassland mosaic habitat. Until now, certain influential factors of reintroduction sika deer population are still unclarified. Consequently, further research would be improving research directions, e.g., human disturbance, road distribution and the presence of stray dogs. These will provide references of management and implementations for their additional conservation.