BIRDS OF PREY 147 
bones and hair of the smaller quadrupeds ; also a number 
of pellets ejected by the old birds. I am certain that 
both birds occupy the nesting cavity at night, for there 
was a depression in the end of the cavity which showed 
signs of being occupied by one of the birds. 
“The nest contained five eggs, rather light in color for 
this species. They have a yellowish brown appearance, 
the color being almost solid but darker about the larger 
ends.” 
It is a matter of regret that Mr. Howard gives us no 
record of how the adults conducted themselves during 
the time they were being robbed ; also, that he did not 
make a study of the feeding and nesting habits of the 
birds with regard to incubation and care of the young, 
as this is a field open for just such daring observers and 
one where good work is needed. 
337b. WESTERN RED-TAILED HAWK. — Buteo 
borealis calurus. 
Famity: The Falcons, Hawks, Eagles, ete. 
Length: Male 19.00-22.50 ; female 23.00-25.00. 
Adults: Varying from light grayish brown to uniform dark sooty brown ; 
under parts white or buffy, with broad brown streaks on throat, belly, 
and sides ; tail bright reddish brown in any phase, crossed by one or 
more black bars. In the dark extreme the entire plumage except the 
red tail is a dark sooty brown. 
Young: Darker throughout, and more heavily spotted; tail grayish 
brown, barred with black bands. 
Geographical Distribution: Western North America, east to Rocky 
Mountains, south to Mexico. 
Breeding Range : Almost throughout the State of California. 
Breeding Season: March, April, and May. 
