本研究在恆春半島利用月亮觀察法,配合雷達觀測,來探討春季夜間遷移性鳥類數量的時空分布及受氣象因子的影響。結果顯示,月亮觀察及雷達觀測有所差異,是因月亮觀察受限的程度較大,以雷達觀測可以得知較廣面候鳥經過恆春半島上空的時空分布。雷達觀測春季主要的遷移時間集中在4月中旬到5月下旬,其中4月及5月的遷移量指數分別佔46.68%和45.76%,而6月的遷移量指數只佔7.56%,已趨近遷移末期。藉由遷移性鳥類的出發地與抵達地的距離,可得知約在凌晨12點時,就可在恆春半島最南端的取樣範圍內,看見候鳥開始大量的朝向恆春半島遷移而來,遷移量於凌晨2點達到高峰,之後緩慢下降。遷移的空間分布主要是以東部海域為主(36.33%),恆春半島次之(34.56%) 西部海域再次之(29.1%);而遷移量指數在不同高度的空間分布顯示,隨著高度越高,西部海域的遷移量指數分布的比例會越多。分析氣象因子對遷移量的影響發現,以風向影響遷移量較顯著(p=0.046),風速和雨量因子則不顯著(p>0.05)。順風的平均日遷移量指數最高(924.7±1672.22),順側風的日遷移量指數次之(309.9±479.29)。當風速越快時飛行高度越低 (r =-0.329, p=0.002)。
At Hengchun Peninsula, moon-watching and weather radar were applied to determine the spatiotemporal pattern of the number of migratory birds at night and its relationship with weather in the spring of 2007. Result from the moon-watching method, being constrained by its viewing range and scope, was inconsistent with that from the radar image which offered more integral and reliable information. Radar showed spring nocturnal migration over the Luzon Strait was noticeable during mid-April and late May, constituting 46.68% and 45.76% in April and May, respectively, while it was insignificant in June. Large migration wave could be seen few kilometers off the coast around midnight, reaching its peak at 02:00 h, and then declining afterward. About one-third (34.56%) of migrants flew via the Peninsula, while a larger (36.33%) and smaller (29.1%) proportions via the eastern and western sides of it, respectively. Those flying in higher altitude, however, tended to pass through the western side of the Peninsula. Migration magnitude was influenced significantly by wind direction (p=0.046), rather than by wind speed and rain (p>0.05). More birds were detected by the radar with tailwind, which was followed by lateral tailwind. As speed wind increased, birds tended to reduce their flight altitude (r =-0.329, p=0.002).
為了持續優化網站功能與使用者體驗,本網站將Cookies分析技術用於網站營運、分析和個人化服務之目的。
若您繼續瀏覽本網站,即表示您同意本網站使用Cookies。