利用覆網實驗研究四草野生動物保護區冬季鷸科候鳥覓食對其餌食生物豐度之影響

外文標題: 
The Impact of Migratory Shorebirds (Scolopacidae and Charadriidae) Feeding on Prey Abundance with Exclosure Experiment in Su Tsao Wild Life Reserve.
校院系所: 
彰化師範大學 生物學系
指導教授: 
姜鈴
出版年份: 
2002年
主題類別: 
摘要: 

四草野生動物保護區是度冬候鳥相當重要的棲息地。對於度冬的水鳥族群而言,覓食是最主要的活動。有文獻指出,在度冬區水鳥強烈的覓食活動,會造成其餌食生物數量的減少。因此,本研究利用覆網實驗,並配合水鳥胃內含物分析及樣區環境監測,以探討四草野生動物保護區水鳥覓食對其餌食生物豐度的影響,藉此了解該保護區度冬期水鳥的覓食生態。 由實驗結果及統計分析可知,一、除在1月22日水深因子顯著高於各天外,其餘各環境因子於各實驗天間並無顯著差異。二、在四草野生動物保護區水鳥覓食會造成底棲生物數量減少,然而如覓食鳥數過少,影響就不顯著。三、底棲生物的減少量與覓食鳥數呈正相關,亦即當覓食鳥數愈多時,底棲生物的消耗量會愈大。四、由水鳥胃內含物分析發現,在當地覓食的水鳥,會以腺帶刺沙蠶、小頭蟲sp.1及粗紋塔蜷為食,而在覆網實驗中亦能得到同樣的結果。五、由晚上進行的覆網實驗,顯示水鳥應會於晚上覓食,並造成底棲生物數量減少。 實驗結果顯示水鳥的分布與底棲生物數量無關,推測可能是底棲生物數量充足,足以負荷水鳥的覓食。在水鳥覓食率的估算上有偏高的情形,可能是由於數據在換算時將誤差放大所致。此外,如能獲得更多有關底棲生物的資訊,如生活史、活動模式等資料,並配合其他方面的實驗和研究,將對度冬侯鳥的覓食生態有更深入完整的了解。

外文摘要: 

The Su Tsao Wild Life Reserve is a very important perching habitat in southwest Taiwan for winter migrant birds. Feeding is the main activity to wintering shorebirds. Therefore, the exclosure experiment and the analysis of stomach content in shorebird were designed to assess the impact of feeding activities of winter shorebirds on the prey abundances in this Reserve Area. According to the experimental results and statistic analysis, I concluded that: (1) Except water depth, other environmental factors were no significance differences in every experimental day. (2) Feeding of shorebirds declined the numbers of the invertebrates, however, the numbers of birds were few, the numbers of the invertebrates no significant declined. (3) The reduced quantity of invertebrates was positively correlated with the numbers of shorebirds. (4) From the study of stomach contents, shorebirds consumed Thiara riqueti, Neanthes glandicincta, and Capitellidae sp.1. Exclosure experiment produced the same result. (5) At night, shorebirds still fed and reduced the numbers of invertebrates. The result also presented that the distribution of shorebirds was no concern with the invertebrate numbers. The possible reason for this would be the invertebrates were abundant to supply the consumptions of shorebirds. The feeding rate of shorebirds might be over estimated by mathematical magnification. In addition, more information about resident invertebrates, such as life cycle and activity times, will provide more thorough understanding in the feeding ecology of winter shorebirds.