Macrohabitat Characteristics and Distribution Hotspots of Endemic Bird Species in Taiwan

• Main Authors: Chia-Ying Ko, Ruey-Shing Lin, Pei-Fen Lee
• Format: Article
• Language: English
• Published: National Taiwan University 2010-09-01
• Series: Taiwania
• Subjects: biodiversity inventory; macrohabitat; canonical correspondence analysis; endemic bird species; biodiversity hotspot
• Online Access: http://tai2.ntu.edu.tw/taiwania/abstract.php?type=abstract&id=1138

Understanding species distributions is essential for developing biodiversity conservation strategies. We combined two bird inventories conducted from 1993 to 2004 and identified specific features of 17 endemic bird species in Taiwan. We used eight environmental variables, including elevation, annual total precipitation, annual mean temperature, warmth index, percentage of forest cover, mean Normalized Difference Vegetation Index (NDVI), percentage of building area, and road density, to define macrohabitat characteristics of each species. All the data were in a 1 × 1 km gird system. The 17 species were classified as common (being present in more than 200 grids), uncommon (100–200 grids) or rare (less than 100 grids). The Mikado Pheasant (Syrmaticus mikado), as a rare species, had the lowest occurrence records, while the Taiwan Barbet (Megalaima nuchalis), as a common species, had the highest. Each species had a specific distribution range and habitat preference. These 17 species occupied heterogeneous elevation and climatic conditions. In general, they favored habitats with high vegetation cover, at almost full forest cover and median to high NDVI. Canonical correspondence analysis (CCA) indicated that elevation had the highest correlations with species distributions, with axis 1 accounting for 57.5% of the variation and axis 2 for 9.8%. The endemic species in Taiwan could be classified into three groups mainly separated by elevation based on the CCA. Potential biodiversity hotspots, in the elevation range of 300 and 1500 m with 45%-100% forest cover, included 33.2% areas of Taiwan. Only 35% of actual hotspots (grid with the number of endemic species ≧7) were located in the potential hotspots. Most of the actual hotspots (65%) occur at higher elevation than the potential hotspots. These data demonstrated the distribution patterns of the endemic bird species in Taiwan, and topography and vegetation are the most important macrohabitat factors associated with these species.