Habitat Suitability Index (HSI) models to describe habitat quality for selected fish and wildlife species were initially developed by the U.S. Fish and Wildlife Service (FWS) in conjunction with other Federal agencies, including the Corps of Engineers. The FWS Ecological Services Manual (ESM) 103 describes more about the models. Although they were developed for assessing impacts of large water resource projects, their utility and flexibility in other areas has been proven. See the list of Habitat Suitability Index (HSI) models (sometimes referred to as the Blue Books) and click to view any of those indicated by a pdf. The models can also be accessed from the U.S. Geologic Survey National Wetlands Research Center page: http://www.nwrc.gov/wdb/pub/hsi/hsiindex.html.
In addition to those published by the FWS, several additional HSI models and Suitability Curves (components of a model) have been constructed and published in other formats. Those of which we are aware are listed in the following sections and available as .pdf files or links to the Web. The models and Suitability Index curves are varied in format, explanation, etc. Users are encouraged to browse, based on interest in the taxa listed. Species are listed first, then communities. Thanks to Kelly Burks-Copes and Tisa Webb, ERDC/EL, for locating and obtaining many of these documents.