- 學位論文
花蓮木瓜溪鼯鼠屬之胃內含物氮含量與消化道可塑性研究
Nitrogen concentration of stomach contents and gut size flexibility in Petaurista spp. in Mugua River watershed, Hulien
摘要
若要了解族群動態，其中環境裡的食物資源變化是影響族群大小的關鍵。食物氮含量可以用來評估植食性動物的攝食品質，同時動物的消化道為了適應多變的環境因子會具有可塑性，提升消化道容量有助於低品質飲食的消化率，並增加動物在冬季低溫或泌乳中雌性的能量收入。因此本研究從2020年6月至2021年7月透過分析白面鼯鼠與大赤鼯鼠的胃內容物氮含量，得知其攝食品質的月變化。同時也測量消化道各部位的長度與乾重，一同探討攝食品質、泌乳、氣候因子與其他可能影響消化道可塑性的原因。結果發現，兩種飛鼠之消化道長度、乾重確實會隨泌乳的能量消耗有顯著增加；而兩種飛鼠攝食品質的月變化呈現相同趨勢，雖然僅在3～5月有相對高的波峰，但全年的攝食品質皆能符合其生存和生殖能量所需，並無顯示較差的月份。也因此消化道長度與乾重的變化在月份間多無顯著差異，而少數有顯著差異者主要受到月均溫的影響。此外，也推測兩種飛鼠還會以其他行為策略、或生理上的調節共同適應環境劣勢。
並列摘要
Nutrition is an important factor affect population dynamics of wildlife, and the concentration of nitrogen in diet is a reliable index of nutrition for phytophagous animals. Additionally, flexibility of the gut, e.g., size expansion to improve the digestion of low-quality diets and increases energy uptake, helps animals to adapt to harsh environmental conditions. In this study, Petaurista philippensis grandis and P. alborufus lena were collected in Mugua River watershed, Hulien, from June 2020 to July 2021. Results showed that both species were relatively high in diet nitrogen concentration from March to May, and the diet quality of the whole year seemed to meet their energy requirement. The length and dry mass of the digestive tract were significantly increased during the lactation period in females for both species. The length and dry mass of the gut has no significant difference in most months, and the few significant differences are mainly related to the average monthly temperature. These two Petaurista species might have other behavior strategies or physiological regulations to adapt to environmental disadvantages.