scholarly journals Logging truck noise near nesting northern goshawks

Author(s):  
Teryl G. Grubb ◽  
Larry L. Pater ◽  
David K. Delaney
2012 ◽  
Vol 132 (3) ◽  
pp. 2063-2063 ◽  
Author(s):  
Teryl Grubb ◽  
Larry Pater ◽  
Angela Gatto ◽  
David Delaney

2013 ◽  
Vol 77 (8) ◽  
pp. 1618-1625 ◽  
Author(s):  
Teryl G. Grubb ◽  
Larry L. Pater ◽  
Angela E. Gatto ◽  
David K. Delaney

Author(s):  
J. David Wiens ◽  
Barry R. Noon ◽  
Richard T. Reynolds
Keyword(s):  

The Auk ◽  
1984 ◽  
Vol 101 (4) ◽  
pp. 761-779 ◽  
Author(s):  
Richard T. Reynolds ◽  
E. Charles Meslow

AbstractThe abundance of resources and their use by Accipiter in two areas within Oregon from 1969 through 1974 are presented. In the coastal mountains of northwestern Oregon only Sharp-shinned Hawks (Accipiter striatus) and Cooper's Hawks (A. cooperii) nested. In the remainder of the state, A. striatus, A. cooperii, and Northern Goshawks (A. gentilis) were syntopic during the nesting season. The number of species and the total density of birds in eastern Oregon were about one-half those in northwestern Oregon. Mean prey size of A. striatus in northwestern Oregon (12.8 g) was significantly smaller than that of the same species in eastern Oregon (28.4 g). Accipiter striatus diets in both areas were composed almost entirely of birds (<5% mammals). Mean prey size of A. cooperii in both areas was nearly the same (134.7 g vs. 136.3 g) and was significantly larger than mean prey size of A. striatus. The frequency of occurrence and the size of prey taxa in A. cooperii diets, however, varied between areas: 74% birds (x̄ = 79.2 g) and 25% mammals (x̄ = 296.4 g) in northwestern Oregon versus 47% birds (x̄ = 123.7 g) and 53% mammals (x̄ = 147.5 g) in eastern Oregon. Mean prey size of A. gentilis in eastern Oregon (306.6 g) was significantly larger than that of A. cooperii and consisted of 55% birds (x̄ = 195.5 g) and 45% mammals (x̄ = 445.2 g). An analysis of prey sizes, prey taxa, and foraging heights indicated that, in general, food was partitioned in both areas primarily according to prey size. In eastern Oregon, however, where A. cooperii and A. gentilis overlapped broadly in prey size, these species tended to take different prey taxa. Both A. cooperii and A. gentilis foraged primarily in the lower zones (ground-shrub and shrub-canopy), whereas A. striatus foraged in the upper canopy.


The Auk ◽  
2001 ◽  
Vol 118 (2) ◽  
pp. 352-365 ◽  
Author(s):  
Sarah R. Dewey ◽  
Patricia L. Kennedy

Abstract Using food supplementation, we tested whether food limits juvenile survival in a population of Northern Goshawks (Accipiter gentilis) in northeastern Utah. The influence of additional food on female nest attendance also was investigated because those strategies may influence predation mortality rates of juveniles. We provided supplemental food near 13 nests from close to hatching until close to independence during the 1996 and 1997 breeding seasons. Thirteen additional nests served as controls and received no supplemental food. We compared the following variables at treatment and control nests: (1) adult female mass, (2) nestling mass and size, (3) female nest attendance, and (4) juvenile survival. Following supplemental feeding, adult females from treatment nests were heavier than their control counterparts, and remained closer to the nest during the latter part of the nestling period and throughout the postfledging period. Nestlings from supplemented nests were significantly heavier than those from unsupplemented nests, but results for size measurements were equivocal. Survival rates for treatment nestlings were significantly higher than controls in 1997, but not in 1996. Those results support the hypothesis that food does not limit avian reproductive success on an annual basis. Most deaths in 1997 were the result of starvation or sibling competition. That observation, and the fact that fed nestlings were heavier, is consistent with the idea that treatment nestlings were in improved nutritional condition. Overall patterns of mass and nest-attendance for adult female goshawks supports the hypothesis that female condition and behavior are adjusted in response to food supplies. However, it is less clear what role the females' presence in the nest stand plays in mediating juvenile deaths, because we did not document predation as a primary mortality factor during the two years of this study. The apparent flexibility in female nest attendance behavior suggests that such plasticity may be an adaptation to lower the risk of predation.


2020 ◽  
Vol 53 ◽  
pp. 126732 ◽  
Author(s):  
Haruki Natsukawa ◽  
Kaname Mori ◽  
Shizuko Komuro ◽  
Takashi Shiokawa ◽  
Jun Umetsu ◽  
...  

The Condor ◽  
10.1650/7448 ◽  
2004 ◽  
Vol 106 (4) ◽  
pp. 826 ◽  
Author(s):  
Sarah A. Sonsthagen ◽  
Sandra L. Talbot ◽  
Clayton M. White

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