Idaho peregrine falcon survey, nest monitoring and release program—1997. Annual Report, Threatened and Endangered Species Project

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In 1982, an attempt to restore the federally listed endangered peregrine falcon (Falco peregrinus anatum) to Idaho was begun through the release of captive-produced young. There were no known nesting peregrines remaining in Idaho at this time (Bechard et al. 1987). The release program ended in 1995. A total of 288 young peregrines have been released within the state (Heinrich 1995, 1987). Many dedicated individuals, agencies, and organizations have contributed to this program coordinated by The Peregrine Fund, Inc. in cooperation with the Idaho Department of Fish and Game (IDFG).
In 1985, the first re-establishing pair of peregrines in Idaho was discovered nesting at one of the release cliffs. In 1988, IDFG began annual surveys and monitoring of nesting pairs within the state. In 1997, these efforts were continued in cooperation with the U. S. Forest Service (USFS).
In 1997, 15 pairs of peregrine falcons occupied territories within Idaho. Ten (67%) were successful; 21 young were produced for an average of 1.4 young per pair and 2.1 young per successful pair. Six of the 21 young (29%) were banded as nestlings: three at one of the occupied release towers and three at the nestbox on the silo of the sugarbeet processing plant.
The 15 pairs monitored represent a two pair (12%) decrease over the number of pairs monitored in 1996. Pairs were not observed at two sites previously occupied in 1996. Most likely the reduction in the number of known (monitored) pairs is more a reflection of reduced monitoring and survey effort than any indication of a population trend. Given productivity figures and the number of incidental sightings reported away from known nesting areas, the population is most likely continuing to increase in the state of Idaho.