- 期刊
福寶與鰲鼓地區渡冬短耳鴞(Asio flammeus)食性
Diet of Wintering Short-eared Owl (Asio flammeus) of Fubou and Augu Areas
摘要
本研究於2003年11月至2004年1月間，在彰化縣福寶與嘉義縣鰲鼓蒐集短耳鴞(Asio flammeus)的食繭，同時調查區內鼠類的組成和數量，以探討度冬短耳鴞的獵物選擇。兩地共蒐集到89個食繭，其中福寶有55個食繭，平均每個食繭內有2.18±1.48隻獵物；鰲鼓有34個食繭，平均每個食繭內有1.88±0.88隻獵物。獵物種類有赤背條鼠(Apodemus agrarius)月鼠(Mus caroli)、小黃腹鼠(Rattus losea)、白齒鼩(Crocidura spp.)、鬼鼠(Bandicota indica)、小雲雀(Alauda gulgula)和蝗蟲(Hieroglyphus sp.)。以個體數量而言，小型獸類是福寶(91.7%)和鰲鼓(96.8%)短耳鴞最常見的食物，兩地都以月鼠占的比例最多，赤背條鼠次之，但小黃腹鼠和昆蟲在福寶食繭占的比例明顯高過在鰲鼓的比例，兩地食性組成有顯著差異。在獵物選擇方面，福寶短耳鴞對月鼠、赤背條鼠的利用顯著地高於野外族群的期望值，但在小黃腹鼠部份是相反；福寶短耳鴞則是對月鼠的利用顯著地高於野外族群的期望值，但在赤背條鼠、小黃腹鼠是相反。推測影響短耳鴞食性的原因，除獵物族群的可利用量外，還包括獵物的體型、棲地類型和敏捷度。
並列摘要
To determine diet composition of overwintering short-eared owls (Asio flammeus), pellets collected of Fubon and Augu areas during November 2003-January 2004 were analyzed. Meanwhile, relative abundance of small mammals was estimated by live-trapping in the respective areas. In the mean time, the pellets were collected for prey selection analyses. Totally, 89 pellets were collected from Fubou and Augu. The number of prey items in each pellet averaged 2.18±1.48 and 1.88±0.88 for Fubou (n=55) and for Augu (n=34), respectively. Prey species identified including: Apodemus agrarius, Mus caroli, Rattus losea, Crocidura spp., Bandicota indica, Alauda gulgula, and Hieroglyphus sp. In terms of number of prey individual, the diet was composed mostly of small mammals, 91.7% for Fubou and 96.8% of Augu. For both areas, Mus caroli was the most common prey, followed by Apodemus agrarius. However, the proportions of Rattus losea and Hieroglyphus sp. were noticeably higher of Fubou than of Augu, and there was significant difference in the composition of prey species between areas. At Fubou, the owl significantly preyed more on Mus caroli and Apodemus agrarius and less on Rattus lose than expected based on trapping; at Augu, the species hunted more on Mus caroli and less on Apodemus agrarius and Rattus lose. It is assumed that the diet of short-eared owl is not only affected by prey abundance, but also by prey's size, habitat structure and agility.