The Use of Weather Radar in Studying Autumn Migration Patterns of Grey-faced Buzzard (Butastur indicus) via Hengchun Peninsula in 2014 and 2015

• Main Authors: Huang, Hsin-Yi, 黃馨儀
• Other Authors: Sun, Yuan-Hsun
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/29005466005417048355

碩士 === 國立屏東科技大學 === 野生動物保育研究所 === 104 === I used Doppler weather radar to analyze the migration patterns such as flyway, flock size, arrival time, flight altitude, flight speed, and the effect of wind condition of Grey-faced buzzards (Butastur indicus) in October 2014 and 2015 via Hengchun Peninsula. I also compared the radar data with ground observations of 2014 and 2015 to examine why the number of Grey-faced buzzard observed declined drastically in 2015. In 2014, radar images showed 152 flocks and the number total of the birds was 106,697. There are 16 % of them flying through the west to Hengchun Peninsula, 70 % flying through Hengchun Peninsula, 14% flying through the west to Hengchun Peninsula. In 2015, radar images showed 138 flocks and the total number of raptors was 89,260. There were 55 % of them flying through the west to Hengchun Peninsula, 41% flying through Hengchun Peninsula, 3 % flying through the west to Hengchun Peninsula. The percent of the buzzards unseen by ground observation in 2014 was 48 %, while that of 2015 was 61 %. The time of passing through the Peninsula was from 5:00 am to 3:00 pm in 2014, and 5:00 am to 2:00 pm in 2015. The lowest flight altitude of the species flying into radar scanning range was 136.7-1148.9 m and that of flying out the scan range was 133.0-573.6m in 2014. The lowest flight altitude of the buzzards was 136.7-1148.9 m and the highest flight altitude was 133.0-573.6 m in 2015. In 2014, the flight speed of the birds was 4.3-86.2 km/hr, and most flew with tailwind, while in 2015, it was 10.7-96.4 km/hr, mostly with laterally tail wind.