The Huajiang wetland is an important wintering site for a population of the migratory common teal, Anas crecca. Three habitat variables, slope, substratum elevation and distance to the nearest vegetation, were measured and used to construct habitat suitability index (HSI) models for the conservation of the wintering population and management of the wetland habitat. Two HSI models, the "minimum function" and the "regression", were developed. The results indicated that the common teal preferred localities with low slope (0.7 to 1.4 %), low substratum elevation (0.3 to 0.7 m above the mean sea-level) and close proximity to vegetation (distance to the nearest vegetation < 4 m). According to a validation dataset, only the "regression" model accurately predicted the teal's habitat preference. Habitat suitability maps showed that the area classified as good or excellent (HSI values > 0.5) accounted for 84.8 % of the entire study site. This model suggested that substratum elevation was the most important variable affecting the quality of the common teal's habitat. Our findings provide a useful basis for determining potential habitats for the common teal and for restoring degraded habitats. Our study is also applicable to other waterfowl species in Taiwan and the wintering areas for common teal in other regions.
