環境昆蟲量對五色鳥（Megalaima nuchalis）幼鳥生長與存活之影響

Effects of Arthropod Abundance on Nestling Growth and Survival of Taiwan Barbets (Megalaima nuchalis)

環境食物資源量影響幼鳥的生長與存活，都市地區可能因節肢動物量較自然環境低，造成都市裡的野生幼鳥存活率較低。本研究調查都市公園綠地及自然環境兩地的五色鳥幼鳥離巢率及失敗原因、環境昆蟲量、親鳥餵食昆蟲頻率、幼鳥生長速度等，發現都市公園綠地可利用的昆蟲量較少、親鳥餵食幼鳥昆蟲頻率較低、幼鳥生長較緩慢、夭折占離巢失敗比例較高，以及幼鳥體型差異較大的繁殖窩有較低餵食昆蟲頻率及較易發生夭折。本研究推測昆蟲為五色鳥幼鳥生長的關鍵食物，都市公園綠地的昆蟲量不足可能造成五色鳥幼鳥生長遲緩及夭折率提高，建議利用棲地經營管理增加都市地區公園綠地的昆蟲資源，並杜絕對昆蟲及其棲地的破壞。

Food abundance in the environment influences nestling growth and survival in birds. In urbanized areas, nestling survival is likely to decrease due to low arthropod abundance. We investigated the fledgling success rate of the Taiwan Barbet (Megalaima nuchalis) and the causes of fledgling failure in an urban green space and a natural habitat. In the two sites, arthropod abundance, arthropod provision rates by parents, nestling growth states were recorded. The results show the less arthropod abundance, the lower arthropod provision rate, slower nestling growth and more premature death of nestlings in the urban green space. Furthermore, the clutch with nestlings of distinct body size differences had lower arthropod food provision rate and more premature deaths. The results indicate that arthropods are a vital food resource for nestling growth of Taiwan Barbet. Insufficient arthropod abundance in the habitat will likely cause slow growth and premature death of nestlings. To enhance arthropod abundance in urban green space, appropriate habitat management is needed, and any damage to the arthropod community and its habitat should be prevented.