60 BIRDS J.\ THEIK RELATIONS TO MAN. 



Sixteen canaries mentioned by Dr. Stanley ^ ate one hun- 

 dred grains of food per day, about one-sixth of their own 

 weight. '^ A gull kept and fed in a garden devoured in one 

 day fourteen mice and two rats. Another was seen to swal- 

 loAv an entire rat, an operation, however, not accomplished 

 without some difficulty, the bird making several efforts before 

 it succeeded, and even then the tail remained visible for sev- 

 eral minutes." ^ 



In The Ameincan Katuralist for July, 1899, Dr. Thomas H. 

 Montgomery, Jr., gave some valuable data concerning the food 

 of owls, based on a study of food pellets regurgitated at roosts. 

 In the winter of 1898-99 four long-eared owls took residence 

 in an arbor-vitae tree on Dr. Montgomery's grounds at West 

 Chester, Pennsylvania, and from December 25 till February 

 22 were under his observation. Pellets were gathered weekly 

 and analyzed. In the fifty-nine days the pellets from beneath 

 this one tree yielded remains of two birds, one shrew (Bkt- 

 rina), one common mouse (J/^/.s), and three hundred and 

 forty-five field-mice [Microtus). Under a Norway spruce near 

 by, where a short-eared owl roosted regularly and one of the 

 long-eared occasionally, were found between February 26 

 and Marcli 26, twenty-eight days, evidence of one crawfish, 

 five birds, two shrews, one jumping mouse (Zapns), and one 

 hundred and five field-mice. Pellets believed to have come 

 from tlie same owls, found under trees within a radius of an 

 eighth of a mile, contained remains of five birds {Begulus, 

 Junco, Ccrthia), seven shrews, and one hundred and forty- 

 eight mice. Taken altogether here was an equivalent of one 

 owl for two hundred and forty-six days, to which are credited 

 twelve small birds, ten shrews, and six hundred mice, or 

 about two and one-third animals, mainly mice, per day. 



For twenty-two consecutive days, December 25 to January 

 15, Dr. Montgomery counted four owls in the arbor-vitae tree 



1 History of Birds, p. 225. '' Id., p. 143. 



