Cooper's hawks in urban and exurban areas: A reply

Bielefeldt and Rosenfield (2000) argued that we (Boal and Mannan 1999) failed to demonstrate a difference in productivity between pairs of Cooper's hawks (Accipiter cooperii) in urban and exurban areas in southeastern Arizona. Here we show that if mortality of nestlings and fledglings to agents other than trichomoniasis is about the same in urban and exurban areas, then survival of young Cooper's hawks to 45 days is 91% in exurban areas and 49% in urban areas. Bielefeldt and Rosenfield (2000) also criticized us for failing to demonstrate that Tucson is an ecological trap for Cooper's hawks. In our 1999 paper, we offered the idea of 'Tucson as an ecological trap' as speculation, and identified the kinds of information that would be needed to determine if the speculation was true. However, most of Bielefeldt and Rosenfield's (2000) criticism on this subject stems from differences in how we and they view the concepts of 'population sink' and 'ecological trap.' Bielefedlt and Rosenfield's (2000) critique has not changed any of the conclusions, interpretations, or speculations we presented in Boal and Mannan (1999).