190 BULLETIN 17 0, UNITED STATES NATIONAL MUSEUM 



Dr. Paul L. Errington (1932c), in summarizing his study of the 



food of this owl, says: 



It can perhaps be surmised from the data, without discussion, that the food of 

 the Barred Owls was determined in the main by what was available to them. 

 Their food was further determined by what was within the power of their weak 

 feet to kill. The ordinary size limit for avian prey was the flicker; for mammalian 

 prey, moles and part-grown cottontails. The mink listed in no. 20 is the one 

 glaring exception that I have encountered, though it is not to be said positively 

 that the mink had not died from causes other than Barred Owl talons. Possibly 

 it had attempted liberties with the tethered owlet. Altogether, the Barred 

 Owl seems endowed with about as mild a personality as a raptor could have and 

 yet maintain a predaceous existence, in some instances subsisting for considerable 

 periods upon large invertebrates (insects and crayfish) or upon fish or amphibians. 



He says elsewhere (1930) that "in one experiment 55 English 

 sparrows (released alive in cage) were eaten in 154 hours" by one owl; 

 and 49 sets of mandibles were recognized in the pellets. This partially 

 upsets the theory that pellets are unreliable as indicators of birds 

 eaten. 



Mr. Bolles (1890) says that his captive owls considered mice "a 

 rare treat, and they swallowed them without hesitation, head fore- 

 most." He once "found a large number of mice in a barrel of excelsior. 

 Carefully taking out most of the packing," he placed one of the owls 

 in the bottom of the barrel. "The mice spun round him in confusing 

 circles, but with great coolness he caught one after another until 

 nineteen were disposed of. The Owls between them ate the entire 

 number within six hours." They had never seen fish until he put 

 some live perch and bream in their bathing tank, but they soon caught 

 and ate them all. They also caught and devoured live frogs that he 

 placed in their cage. He could not keep the owls in the sunny cellar 

 where his hens were, for they caught and ate some of his pullets "and 

 terrified the survivors so that their lives were a burden." 



Lewis O. Shelley has sent me some interesting notes on the capture 

 of a cottontail rabbit by a barred owl in winter, and a diagram showing 

 their tracks in the snow. He says that "the owl's talons, from visible 

 signs, became fastened in the rabbit's back, midway; and for an even, 

 erratic 84 yards the rabbit ran, with the owl holding fast and every so 

 often flapping its wings to maintain a balance, or trying in vain to 

 launch into the air, as wing marks in the snow, on either side of the 

 trail made by the rabbit, showed. For all this distance the rabbit 

 labored, not on a steady run, but with spasmodic hops and rushes, for 

 its belly every so often flattened into and trailed the snow." The 

 rabbit tried twice to free itself from its enemy by running under bushes 

 or low branches, but in vain. Where the conflict ended was found 

 "an owl pellet and a rabbit's hind leg. The fur-lined arena held 

 numerous rabbit tracks and those of the owl." 



