We conducted intensive helicopter-supported surveys to assess the distribution, occupancy, and reproductive rate of Peregrine Falcons (Falco peregrinus anatum) in the Yukon-Tanana uplands of interior Alaska 1995–2003. We surveyed specific reaches of Birch Creek and the Goodpaster and Salcha rivers in this remote area to monitor this nesting species. Each year, we visited potential cliff-nesting areas and known nesting territories during early incubation (late May) to assess occupancy and nesting activities, and during the late-nestling period (mid-July) to count young, document nesting success, and measure reproductive rate. We identified 55 different nest cliffs occupied by Peregrine Falcons during at least one year of our survey. The number of occupied nesting territories detected each year increased from a low of 12 in 1995 to a high of 38 in 2002. Reproductive rate averaged 1.6 young/occupied territory and 2.4 young/successful territory for the nine-year period. The percentage of successful territories each year ranged from 42% to 81% (mean = 65%). Little is known about Peregrine Falcon numbers and distribution in the Yukon-Tanana uplands prior to the DDT-induced decline, but they are currently the most abundant cliff-nesting raptor in the region. Monitoring these remote areas may provide a valuable tool to alert us to population declines before they occur in larger drainages.
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1 June 2011
Recovery and Trends of Peregrine Falcons Breeding in the Yukon-Tanana Uplands, East-Central Alaska, 1995–2003
Robert J. Ritchie,
John E. Shook
Journal of Raptor Research
Vol. 45 • No. 2
June 2011
Vol. 45 • No. 2
June 2011
Alaska
detectability
Falco peregrinus
nesting
occupancy
Peregrine Falcon
population