Browsing UAF Graduate School by Author "Jacobs, Jefferson M."
Factors influencing the productivity of peregrine falcons (Falco peregrinus anatum) in the Fortymile wild and scenic river corridor, AlaskaJacobs, Jefferson M. (2003-05)I conducted the first comprehensive occupancy and productivity surveys of Falcon peregrinus on the Fortymile River during 2000 and 2001. I tested feather samples of nine nestlings for mercury contamination, examined effects of human disturbance, and assessed correlations of nest productivity to aspect and distance from ponds. Twenty and 22 nests were occupied in 2000 and 2001 and productivity averaged 0.88 and 1.33 nestlings per nest respectively. Mean feather mercury concentration was 3.85 ppm, and ranged from 1.88 ppm to 7.13 ppm. High variability in timing and intensity of disturbances and limited sample sizes precluded a study of disturbance effects. Peregrines selected nest-cliffs with southern aspects in 2001. North aspect nests were most vulnerable to failure in 2000. Nests within 6 km of a pond had higher productivity than those farther from ponds. The Bureau of Land Management is encouraged to continue annual occupancy and productivity surveys of the population.