人為干擾對麻雀驚飛距離之影響

Abstract

隨著人們對於生物多樣性的重視程度提高，都市成為生態保育執行的重要區域。研究野生動物如何成功在都市中生存，以及都市化對於都市野生動物的影響，都是當今都市生態學者研究的重要議題。其中，都市公園作為都市野生動物重要的棲地，也是人類休憩活動重要的場所，野生動物的生存空間與人類遊憩空間重疊，將使兩者之間產生互相影響或衝突的情況。另一方面，都市公園兼具遊憩、防洪、教育、生態等功能，公園中的植被結構、人造物結構與人類活動類型亦不盡相同，公園結構與人為活動對於公園中野生動物之影響有待探究。麻雀 (Passer montanus) 作為都市普遍的台灣原生鳥種，其生活史與人類活動關係密切，且麻雀等常見鳥類的全球族群數量目前正在減少，因此選擇麻雀作為觀察對象，以驚飛距離分析麻雀受公園結構與人為活動的影響程度。 本研究挑選台北市4個麻雀出現數量穩定的都市公園－大安森林公園、二二八和平公園、林森康樂公園、榮星公園作為樣區，自2011年3~11月進行觀察，每月量測公園中麻雀的驚飛距離，並紀錄麻雀出現地點的微棲地結構與人為活動頻率；另外挑選台北市4個麻雀數量稀少的都市公園－民權公園、民生公園、松德公園、信義安康公園做為對照，並將8個公園之航照圖以ArcGIS 9.3數化其公園結構，計算植被與人造結構覆蓋比。以相關分析、主成份分析與一般線性迴歸分析了解公園中的微棲地結構主成份與人為活動頻率對麻雀驚飛距離的影響。 結果發現麻雀與人對於公園的使用時間與空間上有資源分隔 (resource partitioning) 的現象；公園面積、水體覆蓋比與人為餵食頻率對於麻雀群集平均數量多寡有顯著正相關；各公園麻雀之驚飛距離有顯著差異，且與驚飛距離有顯著相關之因子皆不同，顯示麻雀確實有習慣公園內人為活動的情況存在，且習慣程度不一；而周邊之灌木叢與人造結構均能提供麻雀避棲，進而降低麻雀驚飛距離。二二八公園麻雀在繁殖季驚飛距離較非繁殖季長，顯示麻雀在習慣都市化棲地的情形下，雖可能具有過低的驚飛距離，但人為活動仍可能會干擾其繁殖季之活動與族群之存續。

Nowadays, since biodiversity consideration is growing important concern for human well-being, urban areas are going to be target areas to implement ecological conservation. To understand what factors affecting wild animals to successfully live in urban areas is becoming a very important issue for urban ecology studies. Urban parks are not only as crucial habitats for urban wild animals but also the places for human recreation activities. Usage overlaps between wildlife habitat and human recreation can cause interactions or conflicts between human and animals. Urban parks provide recreational, flood control, educational and ecological functions; however, effects of vegetation structures, man-made structures and human activities on wild animals can be different at each park. Tree sparrow (Passer montanus) as a common native bird species was chosen as a study subject, because its life history is closely related to human activities, and the populations of common bird species, such as tree sparrow, are decreasing around the world. Therefore, tree sparrow will be a suitable species to observe urbanization effects on wild bird. Four urban parks in Taipei, including Da-an forest park, 228 peace memorial park, Lin-sen Kang-le park, and Rong-xing Park, were selected as study sites. Field observations were conducted from March to November, 2011 to understand effects of park structures and human activities on tree sparrows. I recorded flush distances and micro-habitats surround tree sparrows each month. Aerial photography of different parks was used to calculate the vegetation cover and the percentage of impervious area. Finally, relationships between flush distances and different human disturbance factors were analyzed using Pearson correlation, principal component analysis and general linear model regression. Based on observations of tree sparrow distributions in study sites, I found that there is resource partitioning between tree sparrow and human activities. Park area, the percentage of water cover, and the frequency of human feeding have significant positive relationships with the flock numbers of tree sparrow. There are different human disturbance factors affecting the flush distance of tree sparrow in each park. In addition, tree sparrow showed a different degree of habituation to human disturbance at different parks. Bush and man-made structure were found to reduce the distance of tree sparrow. Finally, tree sparrows in 228 peace memorial park showed the lowest flush distance by habituation, but their flush distance are longer in breeding season than in non-breeding season. This result suggests that human activities may still disturb tree sparrows’ activities in breeding season and pose potential threats on the reproduction of wildlife populations.