Parental care of peregrine falcons in interior Alaska and the effects of low-altitude jet overflights

• Main Author: Palmer, Angela G.
• Other Authors: Roby, Daniel D., Schafer, Dan, Collopy, Mike, Oregon State University. Graduate School
• Format: Master Thesis
• Language: English; unknown
• Published: Oregon State University
• Subjects: Peregrine falcon > Reproduction > Alaska; Peregrine falcon > Effect of habitat modification on > Alaska; Peregrine falcon > Effect of noise on > Alaska; Falco peregrinus; peregrine falcon; Alaska
• Online Access: https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/qn59q7723

To assess the impact of low-altitude jet overflights on parental care, we examined nest attendance, time-activity budgets, and provisioning rates of 21 Peregrine Falcon (Falco peregrinus) pairs breeding along the Tanana River, Alaska in 1995 and 1996. Several intrinsic and extrinsic factors influenced attributes of nesting behavior. Female nest attendance declined substantially with progression of the nesting cycle, while male attendance patterns were consistent throughout the nesting cycle. Further, although females typically performed most of the incubating, male attendance at the nest area varied considerably among breeding pairs. Both prey item delivery rates and estimated prey mass delivery rates increased with brood size. Prey item delivery rates per nestling, however, decreased with increasing brood size; yet estimated prey mass delivery rates per nestling did not vary with brood size. Peregrine Falcons apparently maintained constant provisioning rates per nestling as brood size increased by increasing average prey size. We found evidence that nest attendance and time-activity budgets of Peregrine Falcons differed during periods of overflights compared with reference nests, but differences depended on stage of the nesting cycle and gender. Males had lower nest ledge attendance during periods when overflights occurred than males from reference nests when data from the incubation and early nestling-rearing stages of the nesting cycle were combined. Females apparently compensated for lower male ledge attendance by attending the ledge more during overflown periods compared to females from reference nests, although this trend was not significant. During late nestling-rearing, however, females perched in the nest area less during periods when overflights occurred than females from reference nests. We did not see a relationship between nest attendance and the number of overflights, the cumulative number of exposures experienced by each nesting pair, or the average sound exposure level of overflights. Nor did we ...