| Abstract: | 反嘴珩(Recurvirostra avosetta)在台灣屬於局部地區普遍的冬候鳥, 主要族群只集中於台南的四草地區. 由85-87年的野外觀察中顯示反嘴珩會出現於幾池特定且有水體之魚塭中, 然而當地相似的環境很多, 哪些才是影響反嘴珩分布的重要因子仍不清楚, 因此本研究自85年11月至86年4月, 及87年1月至87年3月, 在反嘴珩活動之魚塭區進行族群分布, 水深, 鹽度因子與食物量的調查, 並配合覓食行為的觀察, 以分析其影響選擇棲地之環境因子.由結果顯示, 反嘴珩在四草地區呈現不隨機的分布. 從各因子與反嘴珩族群關係來看, 反嘴珩主要利用低於20cm水深且不乾涸之魚塭, 且由兩年的觀察, 對於不同水深之利用頻率, 都有顯著的差異(P<0.05); 反嘴珩出現的水池之鹽度並不一致; 食物量與反嘴珩族群並無密切的相關性(P>0.05), 顯示鹽度因子與食物量的多寡影響族群的分布並不明顯. 由本研究的結果發現, 三個探討的因子中, 以水深因子對反嘴珩的分布影響最明顯. 比較四種不同等級水深與三種主要的覓食方法發現, 不同等級水深影響其覓食行為的效應是顯著的(P<0.01).
The Avocet is a scarce shorebird along the Taiwanese coast. Most of theavocets winter at fishponds at Szu-Tsao in Tainan. Only a small percentageof the hundreds of apparently identical fishponds are occupied by roostingor feeding avocets. The aim of this study is to identify the factors thatdetermine the selection of specific fishponds by foraging avocets.Feeding behavior observations of avocets were carried out from October1996 to April 1997 and January to March 1998 at Szu-Tsao. Three environmentalfactors, i.e. water depth, salinity and prey abundance in the fishponds, werealso measured.The results showed that wintering avocets are not distributed randomlywith in the Szu-Tsao area. Water depth was found to be the most importantfactor that affected the distribution of avocets (P<0.05); most foraged inwater depths of between 10-20cm. Salinity and prey abundance were foundnot to be considered not a determinate factor in the avocet distributionobserved. In comparing the the three main foraging methods used with waterdepth, the latter divided into four classes (level 1: 0-1cm, level 2: 1-10cm, level 3: 10-18cm, level 4: >18cm), a significant relation was found(P<0.01, n=52).-1 -aA study of factors affecting on feeding habitat selection by wintering Avocets at Szu-Tsao area of Tainan, Taiwan |
