WEEK-ENDS WITH THE PRAIRIE FALCON 



625 



Another peculiarity 

 in nesting beliavior was 

 noted at the "nest on 

 tlie cliff" in 1929. In- 

 stead of placing their 

 eggs in clear view on 

 the ledge, as they had 

 done the previous year, 

 the falcons chose a pot- 

 hole six feet below it. 

 In this position the eggs 

 could not be photo- 

 graphed, so we shifted 

 the whole set to the old 

 nesting depression. 



Then for the next 

 half hour we watched 

 one of the keenest- 

 sighted of all birds fly 

 directly past its eggs, 

 clearly visible and very 

 conspicuous on the 

 ledge, and go back in- 

 to the pothole from 

 which they had been 

 removed. While in the 

 pothole the old bird 

 mooned around as sol- 

 emnly as an owl and 

 uttered puzzled clucks. 



This seems to be a 

 typical falcon reaction, 

 for a fellow observer re- 

 ports that a duck hawk 

 once refused to follow 

 its clearly visible eggs 

 when they had been 

 moved only two feet! 

 It, too, went back to 

 the exact spot where 

 the eggs had been laid. 



After we had watched 

 the antics of the old 

 bird in the pothole until 

 it was certain she would not follow her eggs, 

 they were put back. Soon after, they dis- 

 appeared and are now probably resting in 

 some collection. 



THE VARIED DIET 0? THE FALCON 



What is the normal diet of the prairie 

 falcon ? To this question there is no definite 

 answer. 



Food remnants found at one nest by the 

 writer and analyzed through the kind co- 

 operation of Prof. J. O. Snyder, Department 

 of Zoology, Stanford University, by Miss 

 Lydia S. Bowen, then a graduate student. 



A BOX SEAT ONLY SIX FEET FROM THE NEST 



From inside the hanginf; blind the author watched and photographed 

 his falcon friends nesting in the upper cleft, and even "dined" with them 

 (see page 626). The spot seemed a wilderness, but no sooner was the 

 mysterious box in place than herders, driving sheep to summer ranges, 

 began to concentrate and inquire about it. Two years before, a falcon 

 family occupied the lower ledge under the overhanging rock (see illus- 

 tration, page 612) . 



gave a minimum of 4S birds and nine small 

 mammals (gophers and ground squirrels). 

 The most surprising item was a tasty order 

 of eight burrowing owls. 



The classified list of birds was as follows: 

 2 mourning doves, 8 burrowing owls, 3 

 horned larks, 9 California jays, 15 western 

 meadowlarks, 3 Brewer's blackbirds, 2 Cali- 

 fornia shrikes, 1 rock wren, 1 chicken, 1 

 unidentified. 



The female of this pair was one of the 

 largest and the male one of the smallest 

 falcons I have ever seen, but both were 

 superb flyers and mighty hunters, whose 



