Phillip J. Zwank Paul M. McKenzie 1988 A review and synthesis of existing information were used to develop a model for evaluating the quality of habitat for breeding black-bellied whistling-ducks. The model is scaled to produce an index between 0.0 (unsuitable habitat) to 1.0 (optimal habitat). Habitat suitability index models are designed to be used with Habitat Evaluation Procedures previously developed by the U.S. Fish and Wildlife Service. Guidelines for model application and techniques for measuring model variable are provided. application/pdf en U.S. Fish and Wildlife Service Habitat Suitability Index Models: Black-bellied whistling-duck (breeding) reports