Peregrine Falcons, Falco peregrinus, nesting in an urban environment: a review

Abstract

In 1988, 30 to 32 pairs of the Peregrine Falcon (Falco peregrinus) were present in at least 24 cities and towns in North America. Of 24 nesting pairs, only 3 failed and the remaining 21 pairs raised 42 to 45 fledglings (including some fostered young). The production of young per successful pair in 1988 was 2.45 for urban sites vs. 2.51 for rural sites. From 1975 to 1988, 89 percent of 184 peregrines released at Canadian urban sites survived to the flying stage, and in the United States 83 percent of 52 urban-released (hacked) peregrines survived to independence. Bridge sites were associated with a low fledging success. Of 16 urban breeders of known origin, 7 came from rural sites. The height of buildings used ranged from 14 to 50 floors; east-facing sites were most preferred. Prey items were quite diverse with Rock Doves (Columba livia) being most common. The most significant hazards, especially to fledglings, were premature fledging, collisions, and poisoning from pest control programs.