RPI uses data from partnering sites that submit their data to Hawkcount.org and also meet longevity and protocol requirements in a standard and robust way (for more see methodology). The RPI team analyzes data every three years. The 2019 update data represent 43,455 hours of observation and 8,897,955 migrants counted. Annual index values for each species at a count site are also available for use by the conservation community at large.
RPI launched in 2004 and partners include: the Hawk Migration Association of North America, HawkWatch International, Hawk Mountain Sanctuary Association, and Birds Canada.