remaining three were within a 

 quarter of a mile of Falcons' in 

 neighboring canyons separated 

 by a single ridge. And it is im- 

 possible to tell from the stage of 

 incubation reached which bird 

 is the follower. In two instances 

 nests containing young Ravens 

 were associated with Falcons 

 whose eggs had not yet hatched; 

 but in another notably close in- 

 stance, the Raven laid her first 

 egg on the day the Falcon's 

 eggs were pipped. The remain- 

 ing instances were neutral; i. e., 

 nests of both species contained 

 eggs. The only guess we dare 

 hazard is that both birds reap 

 advantages of warning in case of 

 hostile approach. 



Concurrent with this associ- 

 ation is the annual, or at least 

 occasional, shifting of sites on 

 the part of both species. This 

 shifting is of course quickened 

 by persecution. If unsuccessful 

 in raising a brood one year the 

 bird will try another situation, 

 but always, except in extreme 

 instances, in the same canyon 

 or general locality. In this way 

 the Falcon appropriates the site 

 once occupied by Ravens (and 

 so gets credited with a "stick" 

 nest, though I am satisfied that 

 the Falcon never lifts a twig) ; 

 and the Ravens, in turn, with- 

 out opposition, are allowed to 

 rear their pile in a niche just 

 previously occupied by the Fal- 

 cons. The ruses adopted by birds 

 hard pressed are sometimes 



Photo by the A lilhor 



Taken in Son Luis Obispo County 



REAL SPORT 



THE LOWER FIGURE IS THAT OF THE VETERAN NESTER, FRED 

 TRUESDALE 



