碩士 / 國立屏東科技大學 / 野生動物保育研究所 / 95 / General survey on Tawny Fish-Owl, a rare and secretive species, has been relatively difficult in rugged terrain in Taiwan. To understand its distribution pattern, habitat association, and population status, I compiled 127 field records during 1993-2006 from researchers and literatures, and from bird watchers and local hunters, respectively. Recorded locations within 6.2-km river section (i.e. average of two territories from previous study) were regarded as one territory, which turned out to be 91 territories.
Results showed the owl distributed islandwide except Coastal Mountain Range in the east. It ranged from 48 to 2407 m in elevation. The altitudinal distribution limit was different among regions with the highest location in the central part of the island probably due to Massenerhebung effect, and shrinking abruptly both at the northern and southern end of the island may limit with river distribution. Because most lowland natural forests have been destroyed in the western side of Central Mountain Range, which making the altitudinal distribution median was 536 m higher than in the east where the owl can even reach at some estuaries probably because of ecological release. According to previous reports, there were extensive tracts of forests on central and north-west plains and hills of the island in the 17th century where the owl might frequent.
The owl located at natural forest more than expected by its percentage of area. The minimal percentage of natural forest within each territory 550 m wide both sides was 44.6%. This figure provides valuable information on habitat restoration or river bank exploitation of the owl in Taiwan.
It was estimated that a total of 464 owl territories located on the island based on conditions like 6.2-km territory length, proportion of natural forest, altitudinal distribution, and river width. The owl was still suffering with habitat loss and illegal hunting according to four historical locations in 1960s and our interviewing with hunters. There was about half of predicted owl distribution located outside of any protected area. I suggest establishing protected area with estuary in low-altitude riparian forest in the east.
| Identifer | oai:union.ndltd.org:TW/095NPUST746002 |
| Date | January 2007 |
| Creators | Shiao-Yu Hong, 洪孝宇 |
| Contributors | Yuan-Hsun Sun, 孫元勳 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 91 |
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