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Influences of Territory Composition and Interspecific Competition on Red‐Tailed Hawk Reproductive Success
In north-central Oregon, Red-tailed Hawks (Buteojamaicensis) exhibited a high degree of stability in territory occupancy and territorial boundaries over a 10-yr period. Long-term repro- ductiveExpand
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Variation in the species composition and mean body size of an avian foliage-gleaning guild along an elevational gradient: correlation with arthropod body size
The composition of an avian foliage-gleaning guild was analyzed with respect to body size at nine sites along an elevational gradient in the Oregon Cascades. Mean body size decreased from 20.5 g nearExpand
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Predation by three owl species on northern pocket gophers of different body mass
SummaryWe examined the estimated sizes of Thomomys talpoides in the diets of Bubo virginianus (1,505 g), Tyto alba (437 g), and Asio otus (245 g) in north-central Oregon between 1973 and 1982. TheExpand
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Partial loss of red-tailed hawk territories to swainson's hawks: relations to habitat
Of a population of 33 pairs of Red-tailed Hawks (Buteojamaicensis) inhabiting north-central Oregon, 9 and 10 pairs lost portions of their breeding territories to laterarriving Swainson's Hawks (B.Expand
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Fidelity to Breeding Territory in a Population of Red-Tailed Hawks
-Fidelity to breeding territories was examined on 33 Red-tailed Hawk (Buteo jamaicensis) territories in Oregon from 1973 to 1982 using the incidence of plumage dimorphism and mortality rates.Expand
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Habitat characteristics of Great Gray Owl sites in the Siskiyou Mountains of southwestern Oregon
--Great Gray Owls (St,ix nebulosa) were located at 92 sites, 1991-97, on the northern slopes of the Siskiyou Mountains of southwestern Oregon. We characterized habitat at the 28 sites includingExpand
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The Apparent Use of Rocks by a Raven in Nest Defense
While conducting a study on raptor populations in Wheeler County, Oregon in 1973, on 7 May, John Barss and I witnessed an incident involving the use of rocks by a pair of Common Ravens (CorvusExpand
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