210 BULLETIN 191, UNITED STATES NATIONAL MUSEUM 



They are given to circling in spirals above carrion quite after the man- 

 ner of vultures. I have seen ravens fly by, croaking, and at occasional 

 intervals turn back to make a circle before going on. One day I noted 

 four ravens performing various evolutions in the wind, one had some 

 prey that he would carry a distance in his claws and then transfer it to 

 his bill for a short distance before changing back." 



W. W. Rubey (1933) witnessed some remarkable flight behavior of 

 ravens at the summit of Wyoming Peak (elevation 11,363 feet), Wyo., 

 of which he writes: 



Shortly after noon [October 5] we reached the summit. Immediately we were 

 set upon by a flock of Ravens that dropped down upon us most unexpectedly. 

 The birds, about thirty of them, rushed at us in long, nearly vertical dives, 

 croaking, snarling, and almost barking out their harsh notes. So real did their 

 "attack" appear that we threw rocks in an effort to drive them off. On the 

 first dive, each bird veered off from us at distances of 25 to 100 feet, fell past 

 the peak, then swerved back up and dived again. For a moment, retreat seemed 

 not a bad idea; but soon the Ravens tired of their sport with us and took to 

 another game in which they exhibited a type of bird-flight entirely new to me. 



To the west, Wyoming Peak falls off rather abruptly 3500 feet to the \'allcy 

 of Greys River. The Ravens rose perhaps 500 feet above us, tlien plunged 

 suddenly into a remarkable series of dives, spins, and coasts which eventually 

 carried them almost out of sight to the forests far below. Their maneuver was 

 carried out somewhat as follows: At the top of the preliminary climb each bird 

 turned sharply straight down and fell a short distance with closed (or at least 

 closely cupped) wings. Then, as the speed of fall increased, the wings seemed 

 to open part way and the dive was deflected somewhat from the vertical. Promptly, 

 the Raven began to spin or 'barrel-roll' about its longitudinal or hill-to-tail axis, 

 slowly at first, then more and more rapidly. This rotating fall continued at an 

 accelerating velocity through a vertical distance of several hundred feet. At lenpth. 

 perhaps because the speed could no longer be endured, the wings were opened 

 wider, the angle of dive began to level off, and the axial spinning gradually slowed 

 down until, when the coasting flight became horizontal, rotation ceased. Eaci'i 

 bird immediately swerved back up as far as its momentum would carry it and, 

 from an elevation about 500 feet below that of the start, dived again. Thus, the 

 entire performance was repeated over and over again, each successive dive leveling 

 off farther and farther down the steep mountainside. * * ♦ 



In the two hours that we remained on the peak, the Ravens were there no le.se 

 than eight times. Each time, if I remember correctly, they displayed their trick 

 of spinning dives, and on four of their visits they made their mock attacks on us. 



Three times, however, they found better game than men for their bullying. 

 Once they put up a Golden Eagle from some ledge on the cirque wall north of 

 the peak, and the majestic bird fled shamelessly and with all speed for a peak 

 two miles to the east, with the whole pack in noisy pursuit. Soon they re- 

 turned and quickly routed another Eagle from near the same ledge. This bird 

 fared worse than the first one because he failed to get started far enough in advance 

 of the Ravens. The entire flock surrounded and badgered him relentlessly for 

 some time as he literally fought his way toward the Salt River Range, miles to 

 the west. 



