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105-106年度「龍鑾潭重要濕地(國家級)基礎調查計 畫」 |
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龍鑾潭是國家級重要濕地,〈2016年龍鑾潭保育利用計畫範圍草案〉有更新資料之需。另龍鑾潭指標物種鳳頭潛鴨(Aythya fuligula)數量逐年遞減,原因先前雖有探討但欠缺系統分析。本調查自2016年9月起至2017年8月止,共記錄到18目58科145種鳥類,包含3種新紀錄的小鈴鴨(Aythya affinis)、紅胸鶲(Ficedula parva)、銀鷗(Larus argentatus)。9月為鷸鴴科與鷺鷥科鳥類主要過境期,10月是灰面鵟鷹(Butastur indicus)過境期。10月下旬至11月開啟了龍鑾潭雁鴨度冬期,共記錄12種雁鴨。浮鴨類常棲息於北北岸草澤溼地,而潛鴨類多棲息在潭區,鳳頭潛鴨為大宗,2016年12月調查的數量(583隻)比去年倍增。分析1984年至今,4種常見浮鴨與1種常見潛鴨數量與遊客量、年雨量、冬季月均溫間的關聯。結果顯示,此三因子無法解釋小水鴨(Anas crecca)、琵嘴鴨(Anas clypeata)兩種浮鴨數量波動,不過屬於浮鴨類的尖尾鴨(Anas acuta)和花嘴鴨(Anas poecilorhyncha),前者數量與遊客量呈顯著負相關,但原因尚不明,後者與遊客量呈顯著正相關,推測與旅遊發展衍生的魚塭或水田棄作而形成額外草澤有關,而草澤是已建立留鳥族群的花嘴鴨之潛在巢區。遊客量是解釋鳳頭潛鴨數量的唯一顯著因子(呈負相關),有29.3%的解釋度。年雨量雖與潛鴨數量的正相關性不太顯著,不過值得一提的是,近年間鳳頭潛鴨數量遽減現象也曾出現在雨量僅994 mm的1993年,當年恆春水田停止春耕,鳳頭潛鴨數量由1991年高峰(2182隻)驟減至1184隻。第一次颱風事件前後,15種留鳥總數量並沒有顯著減少,但第二次颱風事件(梅姬與艾利颱風)前後總數量有顯著減少差異,其中黑枕藍鶲(Hypothymis azurea)、烏頭翁(Pycnonotus taivanus)、台灣畫眉(Garrulax taewanus)數量是明顯減少的。兩棲爬蟲類方面,共記錄到4科8種兩棲類與9科18種爬蟲類,外來種包括多線真稜蜥(Mabuya multifasciata)、綠鬣蜥(Iguana iguana) (新紀錄)、亞洲錦蛙(Kaloula pulchra)與斑腿樹蛙(Polypedates megacephalus) (新紀錄)。追蹤的3隻花嘴鴨,帶GPS/GSM發報器的F1追蹤106天、790個點位,第一期插秧日(12月17日)前夜間活動範圍1.31 km²,插秧後夜間活動範圍擴及農田,活動範圍8.44 km²。帶VHF發報器的No.451個體追蹤16天、95個點位,插秧後的日、夜間活動範圍各是2.86 km²,4.50 km²。而No.371個體已於1月5日死亡(只追蹤4天)。2015年較2012年面積增加的依序有次生林、草地、建物,減少的是農地和水文(魚塭)。潭面減少可能來自降雨量。次生林、草地的增加應該來自棄耕的農地和棄養的魚塭。
計畫類別:[動物生態]
英文摘要:Longluan Lake is designated as one of the national important wetland. To renew information for the , we condructed a supplement investigation, and monitored the change of avifauna, herpetofauna, and land use. In addition, the abundance of tufted ducks (Aythya fuligula) has been decreasing by year in the lake, and although there were some speculations by previous researches but they were given without systematic analysis of long-term data. This study was conducted from September 2016 to August 2017. We recorded 145 bird species (58 families, 18 orders), which included the new-recorded lesser scaup (Aythya affinis), red-breasted flycatcher (Ficedula parva), and European herring gull (Larus argentatus). September is the main staging period for the snipes and the heron/egrets, while October is when the gray-faced buzzard (Butastur indicus) pase through. Start with late October to November, the lake enters into the wintering season for waterfowl and 12 species of ducks were recorded. Most dabbling ducks gathered in the marshes of the north shore of the lake, while diving ducks, the most common ducks, basically stayed on the lake with the number of 583 ducks in in December of 2016, roughly doubling the number of last year. The results show that tourist number, annual rainfall, and mean monthly temperature in winter could not explain the population fluctuation of two dabbling ducks—Northern shoveler (Anas clypeata) and Eurasia teal (Anas crecca) but for Northern pintail (Anas acuta) and Eastern spot-billed duck (Anas poecilorhyncha). The former is negatively correlated with tourist number with unknown reason, and the latter was positively correlated with that most probably due to more marsh habitat at abandoned fish farms and paddy fields resulted from tourism/real estate development. The tourist number could explain 29.3% of the variation in tufted duck number. Although the amount of annual rainfall was not positively significantly correlated with the number of tufted ducks, it is worth mentioning that the abrupt drop in the number of tufted ducks in recent years also occurred in 1993 when the rainfall was just 994 mm with 1,184 tufted duck, some half of number record high of 2,182 ducks in 1991. Resident bird abundance declined after 2nd typhoon events but not for the 1st ones, the bird number of Hypothymis azurea, Pycnonotus taivanus, and Garrulax taewanus reduced after the 2nd typhoon events. A total of seven species of amphibians(4 families) and 18 species of reptiles (9 amilies) were recorded, including four alien species such as Mabuya multifasciata, Asiatic painted frog (Kaloula pulchra), Polypedates megacephalus, and green iguana (Iguana iguana)—a new record. We radio-tracked three Eastern spot-billed ducks, and one was tracked with solar GPS / GSM PPT for 106 days. Prior to rice-seedling planting day (Dec. 17th), the duck’s nighttime home range covered 1.31 km², which increased to 8.44 km² after that day for rice seedling at paddy field. Two ducks that wereharnessed with VHF transmitters and among them no.451 has been tracked for 16 days, while No.371 was found dead on 5th January with only 4-day tracking. As compared with the land use composition of 2012, that of 2015 had more second grwoth, grassland, and construction in desending order, but less farmland and fish farm.
計畫屬性:本處委託辦理
執行年度:105
計畫主持人:孫元勳
中文關鍵字:龍鑾潭、鳳頭潛鴨、花嘴鴨、活動範圍
英文關鍵字:Longluan Lake, Tufted Duck, Spot-billed Duck, Home Range