In Taiwan, artificial ponds are originally created on farmlands for irrigation purposes and resident's livehood water. Besides providing water retention for agricultural use, farm ponds also provide habitats to wildlife species, including water birds. However, when humans convert agricultural areas for urban development, it also reduces farm pond's usefulness as wildlife habitats. The purpose of this study is to understand the suitability of farm ponds being waterbird habitats and to establish a framework that could be applied widely to perform habitat suitability assessment on agricultural landscapes by selecting Common Moorhen as the pilot-study species. First, we collected bird survey data and investigated environmental conditions at 75 farm ponds in Chia-yi County. Multivariate analysis was used to analyze the correlation between Common Moorhen's abundance and environmental factors while the Fuzzy Delphi method was applied to establish the hierarchical framework of habitat suitability assessment for farm ponds and to determine the weight coefficient of each factor. Each farm pond was evaluated and assigned a score. The Kappa statistics was implemented to test reliability. Finally, the Matrix analysis was performed on habitat suitability indicators and seasonal abundance of Common Moorhen. Results was preceded to propose the representative farm pond habitat improvement strategies.
Results/Conclusions
Bird survey data showed that the high abundance of Common Moorhen often occurred in winter while it was barely found in summer. Results of the Fuzzy Delphi Method indicated that the inter environmental factors of farm pond is more important than external ones at the top layer of the evaluating framework. At the second layer, the calculation of weight coefficient reveals that "aquatic plant coverage" is the most important factor of internal environmental factors, followed by "drought period," "type and coverage of bush around pond," and "water depth." For external ones, "pond area size" is the most critical factor, followed by “percentage of agricultural land within 200-m radius" and "pond perimeter." Habitat suitability scores are ranging from 2.05 to 4.69 , with the average of 3.12. Study sites with scores higher than 3.147 also have higher abundance. It strongly implies that particular environmental conditions are not only more favorable but also more suitable as habitats for focal species. However, only 19 percent sites were favorable and highly suitable for Common Moorhen, which suggests needs to implement habitat improvement. Findings of this study can assist decision-makers (e.g., government agency) in designing and implementing practices for waterbird habitat conservation on farmlands.