59 



reservoirs and ponds being dry during most of the study. Only 

 In May and June of 198I, too late for breeding purposes, did 

 any appreciable rainfall occur. 



Song Birds 



Sixty-eight species of birds, including game birds, were 

 observed on the study area (Table I8). The Cooper's hawk, 

 ferruginous hawk, golden eagle, prairie falcon, upland sandpiper 

 Brewer's sparrow and field sparrow were listed by Plath (1981) 

 as species of special interest or concern. The ferruginous hawk, 

 golden eagle and prairie falcon are also listed as migratory 

 birds of high federal interest (U.S. D.I. 1979). All of these 

 species are known or suspected to breed in the study are; 

 (Skaar 198O). 



;a 



A total of 813 breeding bird observations (Table 19) were made 

 along aoproximately 20 miles of trail (Figure 4l) during the 

 spring breeding bird roadside surveys. The nine most common 

 birds in the area were, from top to bottom, western meadowlark, 

 lark sparrow. Brewer's blackbird, chipping sparrow, mourning 

 dove, rufous-sided towhee, American robin, house wren and yellow 

 warbler. All seven species had greater than 3.5 percent 

 composition and 15 percent frequency levels in the survey (Table 

 19). The vesper sparrow, brown-headed cowblrd. Brewer's sparrow 

 and kllldeer had percent frequency figures greater than 10. 



Raptors 



Eight species of hawks and one species of owls were observed on 

 the study area (Table I8). Spring observations, which correlate 

 closely with the breeding season, are shown in Figure H2. All 

 other raptor observations are shown in Figure 43. 



A pair of Cooper's hawks was observed in July 198I. They were 

 very defensive and may have had a nest In the area. No other 

 acclplters were observed on the study area. 



Several buteo species were observed. Red-tailed hawks were 

 by far the most common. Three inactive nests were located during 

 a helicopter nest search (Figure 42). They were located in 

 ponderosa pine and Cottonwood trees (Table 20). Several red- 

 tails were observed during the breeding season but their nests 

 were not found. 



A transient rough-legged hawk was observed north of the study 

 area in October. Two fe>rruginous hawk sightings were made 

 during the study (Figure 43). Both were considered to be migratory 

 birds. 



Golden eagle sightings were made on the northeast, northwest 

 and southern edges of the study area (Figure 43). They were 

 always single birds. No nests were located. 



Marsh hawks or harriers were observed over the open fields and 

 sagebrush of the northeast portion of the study area. No nest 



