台灣紫嘯鶇（Myiophoneus insularis）的領域與鳴叫行為

Abstract

台灣紫嘯鶇（Myiophoneus insularis）為廣泛分布於台灣中低海拔溪流環境的特有種鳥類，然而其野外習性仍鮮為人知。2002年10至2004年5月間於烏來及石碇進行本種之無線電追蹤以了解其領域性，並觀察及探討各種鳴叫聲與行為之關連。由石碇觀察的六個領域的個體顯示本種配偶間的活動範圍重疊度大，但與鄰鳥則界線分明，具明顯的領域性，其活動範圍幾乎就是牠的領域。雄鳥維持全功能的終年領域，夜間會回到巢位附近，晨間則在巢位附近鳴唱，且本種利用舊巢的比例很高，推測此類行為之功能與防衛巢位有關，可能有助於來年生殖活動的進行。雌鳥的活動範圍則較不固定。以95%MCP法估計活動範圍達穩定值的3隻個體領域，繁殖期雄鳥為1.89公頃（n=2），雌鳥為3.10公頃（n=1)；非繁殖期雄鳥為1.77公頃（n=2），雌鳥為1.14公頃（n=1)。以95% fixed kernel, LSCV估計繁殖期雄鳥的活動範圍為3.25公頃（n=3），雌鳥為3.62公頃（n=1）；非繁殖期雄鳥為2.35公頃（n=2），雌鳥為1.42公頃（n=1)。清晨、黃昏時常在溪邊常聽到本種的鳴唱及警戒聲。其鳴唱聲長而複雜多變，就目前觀察僅雄鳥會發出鳴唱聲，平均長度為11.1秒，平均頻域為4.3kHz（n=13）。常見之高頻哨音（警戒聲Ⅰ）具警戒之功能，與許多鳥類的警戒聲相似，其主頻率平均為5.5kHz，長度0.80秒（n=14）。研究期間另記錄到警戒聲Ⅱ、社會性叫聲、幼鳥乞食聲及聯繫聲。繁殖期鳴唱高峰持續時間較非繁殖期長（P<0.01），相較於日出時間繁殖期開始鳴叫的時間較早（P<0.05），與其他共域鳥種比較本種繁殖期開始鳴叫的時間有顯著提早的現象（P<0.05）。本種的鳴唱聲長而頻率廣，且無音節高度重複的現象，相對的易受共域鳥種聲音的阻斷及干擾，推測本種提早鳴叫與避免共域鳥種聲音的干擾有關，可能有助於種內個體的溝通。Formosan Whistling Thrush (Myiophoneus insularis) is a widely distributed endemic species near streams in low and med elevation in Taiwan. Very little about its field habit was known. From Oct. 2002 to May 2004, I studied the territoriality of this species by radio-tracking in Wu-Lai and Shi-Ding, and recorded its vocal pattern and behavior. From 6 recorded home ranges at Shi-Ding, they were highly overlapped within pairs and distinctly separated between pairs. Territoriality was found in this species, and the home range was about its territory. Males held all purpose territories year round. They used the area near nest site at dusk, and sang near it at dawn. Besides, there was high probability of old nest reused. Those nest centered activities suggested nest site is very important to the breeding activities of this species. Home ranges of females were less predictable. The home ranges estimated by 95%MCP and 95% fixed kernel, LSCV were 1.89 ha (n=2) and 3.25 ha (n=3) in male, and 3.10 ha (n=1) and 3.62 ha (n=1) in female respectively during breeding season, and 1.77 ha (n=2) and 2.35 ha (n=2) in male, and 1.14 ha (n=1) and 1.42 ha (n=1) in female during non-breeding season. The song and alarm call of this species can usually be heard at dawn and dusk along the streams. Its song was long and elaborate, and only the male was known to sing. The average duration was 11.1 seconds (n=13) and the average frequency range was 4.3 kHz. The alarm call (Ⅰ) was whistles with high frequency. Its average dominant frequency was 5.5 kHz and lasted 0.80 second (n=14). This kind of high frequency whistles is similar to those of many other bird species. Besides, alarm call (Ⅱ), social call, chick begging call, and contact call were also noted. The peak duration of singing activity lasted longer in the breeding season (P<0.01). The timing of the first sound was earlier in the breeding season in comparison with the time of sunrise (P<0.05) and also with other species living in the same area (P<0.05). The characteristic of the song was long in duration and wide in frequency range with very few repeated notes. It may easily be interfered by songs of other coexisting species in the morning which was the peak singing activity of most bird species. That Formosan Whistling Thrush began to sing earlier than other species may be due to the avoidance of acoustic interference, and subsequent advantage in communication with conspecifics.