| Summary: | 碩士 === 國立東華大學 === 自然資源與環境學系 === 100 === Understanding the reactions of avian species to altered habitat is imperative for effective management and conservation of biodiversity. The altitudinal migration in Taiwan provides an excellent object for studying the adaptability of migratory birds because several foraging guilds exhibit migratory behavior and there is higher likelihood for opportunistic change in the types of habitat used during different seasons. This study used line transect surveys to investigate habitat use and preferences among six altitudinal migratory birds. Count surveys were conducted twice per month between 1000 and 2500 meters elevation in the mountains of Taroko National Park in northeastern Taiwan. Observations took place over three seasons before migration (December 2010 to February 2011), after migration (April to June 2011), and during the recruitment of young to the population (July to September 2011). Seasonal variation in the distribution and abundance of study species was likely influenced by migration, recruitment of young, and changes in flocking behavior. However, the habitat preferences of all six species stayed the same throughout the year. Taiwan Yuhinas (Yuhina brunneiceps) preferred forest habitats over orchard habitats. Grey-cheeked Fulvettas (Alcippe morrisonia) used forests around 1500m, particularly in winter. The Red-headed Tit (Aegithalos concinnus) and Collared Bush Robin (Erithacus (or Tarsiger) johnstoniae) used all habitat types observed through the year. Green-backed Tits (Parus monticolus) used edge habitats more often at high elevations than low elevations (p < 0.003), as did Taiwan Sibias (Heterophasia auricularis), but both species used forests more often than orchards.
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