US Fish & Wildlife Service


Date of this Version



Green, M.G., T. Swem, M. Morin, R. Mesta, M. Klee, K. Hollar, R. Hazlewood, P. Delphey, R. Currie, and M. Amaral. 2006. Monitoring results for breeding American Peregrine Falcon (Falco peregrinus anatum), 2003. U.S. Department of Interior, Fish and Wildlife Service, Biological Technical Publication FWS/BTP-R1005-2006, Washington DC.


U. S. government work.


In 2003, the U.S. Fish and Wildlife Service (Service) implemented the first of five nationwide monitoring efforts for American Peregrine Falcons (Falco peregrinus anatum) (Peregrine Falcons) as described in the Service’s post-delisting monitoring plan (USFWS 2003). More than 300 observers monitored 438 Peregrine Falcon territories across six monitoring regions. Monitoring in the Southwestern monitoring region fell short of the monitoring goal, where 36 of the targeted 96 territories were monitored; efforts are underway to implement full-scale monitoring in that region in 2006. The five other monitoring regions surveyed sufficient territories to meet the statistical criteria described in the post-delisting monitoring plan. Our estimates of territory occupancy, nest success, and productivity were above the target values that we set in the monitoring plan for those nesting parameters. Additional data collected by this effort documented that the total number of nesting pairs of Peregrine Falcons is estimated at 3,005. Additional data show that 92% of pairs nest on natural substrates in all regions except the Midwestern/ Northeastern region, where only 32% nest on natural substrates. Our estimates of the nesting parameters and the additional data from across the United States indicate that the Peregrine Falcon population is secure and vital. The next coordinated nationwide monitoring effort is scheduled for 2006 (USFWS 2003).