Territory and Habitat Use of Formosan Rufous-backed Shrike(Lanius schach formosae) in Hualien

• Main Authors: Shih-Hung Wu, 吳世鴻
• Other Authors: Hai-Yin Wu
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/84558849880649501723

碩士 === 國立東華大學 === 自然資源管理研究所 === 91 === I studied the relationship between vegetation structure and habitat use pattern of Rufous-backed Shrikes (Lanius schach formosae). I assumed that food availability for shrike, a perch-hunting bird of prey, is determined by perch density and understory coverage, and hypothesized that shrike would concentrate its foraging time and effort in habitat patches with high food availability. The study was conducted on farmland along Hualien River from January to May 2002. The study area was divided into five habitat types according to perch density and understory coverage. Banded shrikes were followed and their perch locations and behaviors were recorded. The observation period of each shrike was divided into three stages, pre-nesting, pre-fledging and post-fledging. The territories of individual shrikes during the study and in different stages were determined by perch locations recorded in specific periods. The result showed that shrikes had stable territories the areas of which correlated with the ratios of the area of low-perch-density habitat type to total territory range. Compositional analysis revealed that shrikes used habitat types with high perch density and low understory coverage more than the other types. There was no significant difference among the areas of territories in the three breeding stages. However, searching time decreased from pre-breeding stage to post-breeding stage. It suggested that, instead of extending territory size, shrikes increased their prey attacking rates to cope with the increasing energy demand across the breeding season.