Geology of the Snake River Birds of Prey Area, Idaho, from Grand View to Walters Ferry

1989 ◽  
pp. 86-96
Author(s):  
Harold E. Malde
Keyword(s):  
Birds Of Prey ◽  
Snake River

Feeding ecology of breeding Long-eared Owls in southwestern Idaho

1984 ◽  
Vol 62 (8) ◽  
pp. 1528-1533 ◽  
Author(s):  
Jeffrey S. Marks
Keyword(s):  
Small Mammals ◽  
Feeding Ecology ◽  
Food Selection ◽  
Prey Type ◽  
Birds Of Prey ◽  
Snake River ◽  
Feeding Niche ◽  
Prey Composition ◽  
Breeding Seasons ◽  
Mammal Faunas

Feeding ecology of Long-eared Owls (Asio otus) was investigated in the Snake River Birds of Prey Area, southwestern Idaho, during the breeding seasons of 1980 and 1981. The owls preyed mainly on five genera of small mammals: Peromyscus, Perognathus, Dipodomys, Microtus, and Reithrodontomys. There was considerable variation in prey composition among sites but not between years. In both years the proportion of Perognathus in the diet increased after the young owls fledged. Compared with other North American studies, Long-eared Owls in the Snake River Birds of Prey Area had a wider feeding niche and preyed more extensively on nonmicrotines. The range of prey sizes in Long-eared Owl diets was similar to that in other areas, with most prey weighing less than 100 g. Interlocality differences in the Long-eared Owl feeding niche probably reflect differences in the composition of small mammal faunas. Long-eared Owls in the Snake River Birds of Prey Area appeared to feed opportunistically on a diversity of available small mammals; prey size, rather than prey type, was the most important factor in food selection.

scholarly journals Influence of Military Activities on Raptor Abundance and Behavior

The Condor ◽  
2001 ◽  
Vol 103 (3) ◽  
pp. 606-615
Author(s):  
Linda S. Schueck ◽  
John M. Marzluff ◽  
Karen Steenhof
Keyword(s):  
Prey Capture ◽  
Military Training ◽  
Birds Of Prey ◽  
Snake River ◽  
Conservation Area ◽  
Small Arms ◽  
Low Levels ◽  
Circus Cyaneus ◽  
Breeding Seasons ◽  
And Behavior

Abstract We investigated the influence of military training on the abundance and behavior of raptors at a military training area in the Snake River Birds of Prey National Conservation Area in Idaho during the breeding seasons of 1991–1994. Raptor counts on military training ranges did not differ when we compared all training days to all non-training days. However, during one period of intensive military training in one breeding season, raptor counts were lower during training than on non-training days. During training, Northern Harriers (Circus cyaneus) did not alter their behavior on training days. In years when prey numbers were low, falcons, hawks, and eagles perched and flew at low levels less often and flew at higher altitudes more often during training than they did when training did not occur. We observed fewer prey capture attempts on ranges on days with training than on days without training. Specific types of military training activity affected counts of raptors on ranges. The lowest raptor counts were associated with firing of artillery, small arms, and main turret guns or machine guns on tanks. Raptor counts associated with tank preparation (i.e., assembling and loading ammunition), driving, laser training, and convoy traffic were similar to non-training periods. La Influencia de Actividades Militares en la Abundancia y el Comportamiento de Aves de Rapiña Resumen. Durante las épocas reproductivas de 1991 a 1994, investigamos la influencia del entrenamiento militar en la abundancia y el comportamiento de aves de rapiña en un área de entrenamiento en el área nacional de la conservación de aves de presa del Snake River, Idaho. Los conteos de aves de rapiña en áreas militares no difirieron entre días de entrenamiento y días sin entrenamiento. Sin embargo, en una época reproductiva los conteos de rapaces fueron menores en días de entrenamiento que en días sin entrenamiento. Circus cyaneus no alteró su comportamiento en días de entrenamiento. Durante el entrenamiento en años cuando los números de presas eran bajos, los halcones, gavilanes y águilas se posaron y volaron en los niveles bajos con menor frecuencia y volaron más alto más a menudo que cuando no había entrenamiento. Observamos menos intentos de captura de presas en días que hubo entrenamiento que en días sin entrenamiento. Las actividades específicas de entrenamiento militar afectaron los conteos de aves de rapiña. Los conteos más bajos estuvieron asociados con disparos de artillería, de pequeñas armas y de las armas principales de la torreta o de las ametralladoras en tanques. Las conteos de rapaces asociados con la preparación de los tanques (ensamblaje y carga de munición), conducción, entrenamiento del laser, y tráfico del convoy fueron similares a los de períodos sin entrenamiento.

Development versus Preservation in the Snake River Birds of Prey Conservation Area

1982 ◽  
Vol 64 (4) ◽  
pp. 756-760
Author(s):  
William F. Hyde ◽  
Alan Dickerman ◽  
Douglas Stone
Keyword(s):  
Birds Of Prey ◽  
Snake River ◽  
Conservation Area
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