藪鳥(Liocichla steerii)鳴唱聲的地理變異

Abstract

第一章 藪鳥(Liocichla steerii) 雌雄間的鳴唱聲巨地理變異 鳥類鳴唱聲的地理變異廣見於許多的鳥種，然而擁有重唱行為的鳥種其雌雄間鳴唱聲上的地理變異卻鮮少被討論到。藪鳥雌雄間具有由公鳥發起，母鳥回應的重唱行為，本研究即針對藪鳥雌雄間的鳴唱聲在全台灣13個族群間的變異趨勢進行研究。結果發現，藪鳥雌雄間鳴唱聲呈現出不同的地理變異趨勢：雌鳥的鳴唱聲不論於同一族群內不同個體間或不同族群間均無顯著的差異；而雄鳥的鳴唱聲在族群間則具有豐富的地理變異。雌雄間鳴唱聲地理變異趨勢不同的原因，推測可能為雌雄間鳴唱聲功能的不同或是雌雄間播遷模式的差異所造成。進一步研究雄鳥鳴唱聲的地理變異趨勢，發現族群間的距離與鳴唱聲的相似性間並沒有顯著的相關。雄鳥的鳴唱聲在同一族群不同個體及不同族群間擁有8種不同的歌曲型(song type)，而不同的歌曲型在地理分布上亦展現出不同的趨勢。其中歌曲型A全部分布於中央山脈的西側，於中央山脈東側則完全沒有紀錄到；而歌曲型B則多出現於東北部及南部，於中部的樣區中並無出現。歌曲型的發展歷史、在不同族群內的接受程度差異以及族群間的地理阻隔都可能是造成歌曲型分布差異的重要因素。 第二章 梅峰地區藪鳥(Liocichla steerii)鳴唱聲的微地理變異 鳥類鳴唱聲的微地理變異著重於探討鄰近族群間的間鳴唱聲的變異及交流情形，或是同一族群內的不同個體之間鳴唱聲變異的地緣關係。本研究逾2004年4 – 8月間，針對台大梅峰山地農場藪鳥雄鳥的鳴唱聲微地理變異進行研究。選取梅峰地區最常見的三種歌曲型，來比較32隻已知領域的雄鳥鳴唱聲。鳴唱聲的相異性與領域的距離間於第三種歌曲型中有顯著正相關。在三種歌曲型個別的群團分析結果，各約有2/3的個體被分在該歌曲型的最大群中，顯示梅峰地區藪鳥雄鳥鳴唱聲的分歧性並不高。檢視依據群團分析結果所繪出的各歌曲型鳴唱聲相似性分群地圖，發現三種歌曲型的分群模式並不一致而有互補的情形，亦即個體可能在一種歌曲型與一個鄰居相似而在另一種歌曲型與另一個鄰居相似。排除歷史、棲息地環境兩個可能造成鳴唱聲變異的因素，形成梅峰地區藪鳥鳴唱的聲地理變異的原因可能來自於鄰近個體間相互的學習或是基因遺傳的結果。

Chapter 1. Sexual difference in macrogeographic song variation of Steere’s Liocichlas (Liocichla steerii) Geographic song variations are common among bird species, but there have been few studies on geographic variations of duetting birds. For different sexes Steere’s Liocichlas, Steerii liocichla, engage in antiphonal duetting which is led by male and followed by female. This study investigated the patterns of macrogeographic song variation for different sexes in 13 populations in Taiwan. The female answer calls showed no significant difference either among populations or individuals, while the male songs showed great differences among populations. The different functions between male songs and female answer calls or the sexual-biased dispersal might lead to the different patterns. The distances and the similarities of male songs between populations were not correlated. Male songs could be classified into eight different song types, and each song type had different distribution pattern. i.e. song type A was only found in the west side of the central mountain, while song type B was common in the north-east and the south part of Taiwan. The history of song type development, how a song type occurred in a population and the geographic factor might all influence the distribution of song types. Chapter 2. Microgeographic song variation of Steere’s Liocichlas (Liocichla steerii) at Meifeng Microgeographic song variation in birds refers to song variations between neighboring populations or neighboring birds within a population. This study examined the microgeographic variation of songs in Steere’s Liocichlas(Steerii liocichla) at Meifeng, central Taiwan, during April – August 2004. Three most common song types (A, B and C) from 32 territorial males were recorded and analyzed. The similarity of song type C between males was significantly negatively correlated with the distances between their territories. According to the cluster analyses of three song types, about 2/3 of males were with similar songs and sorted to the largest group, which suggested the song variation of liocichlas at Meifeng was not diverted greatly. The distributions and patterns of similarities of three song types were sometimes complementary to each other. While the historical and environmental factors were eliminated, song learning behavior and genetic factor might cause the microgeographic song variation in liocichlas at Meifeng.