518 ANNUAL REPOET SMITHSONIAN INSTITUTION, 19 2 8 



probable that only certain red squirrels are bird-eaters, just as only 

 certain tigers are man-eaters, and such individuals should be de- 

 stroyed as soon as evidence against them is obtained. 



Another phase of the relation between squirrels and birds is that 

 hawks and owls prey on the red squirrel, as has been mentioned in 

 the section on enemies. 



A third phase of this relationship is that some birds, such as the 

 white-breasted nuthatch, downy and hairy woodpeckers, bronzed 

 grackle, blue jay, and house sparrow, rob the red squirrel of the food 

 it has stored in the forks of trees. Both the squirrels I have had 

 under observation lost a large part of their stored food in this way, 

 not so much because most of the food w^as eaten by the birds, but be- 

 cause the birds in attempting to eat it knocked piece after i^iece of 

 food out of the forks. Both these squirrels were frequently called 

 upon to defend their stores against these marauders, and when two 

 or more of the birds came into the tree at once they had a very busy 

 time, chasing first one and then another. In chasing these birds the 

 squirrels showed wonderful agility, and many times could, I believe, 

 have caught one of the birds if they had so desired, but in such cases 

 they always jumped short so as not to actually alight on the bird. 



Cram (1901) mentions another phase of the squirrel's relation to 

 birds. He says: 



I have never known him to take part in the general outcry against a hawk or 

 owl. . . . But let him catch a glimpse of an unoffending partridge quietly 

 gathering berries or scratching among the pine needles, and he immediately 

 pretends to fall into an utterly uncontrollable rage. He slowly approaches the 

 bird with short, scratchy starts, down the tree trunk, keeping on the opposite 

 side as much as possible, and peering out from behind the rough bark and pro- 

 tecting branches, as if fully aware of his danger and determined on not expos- 

 ing himself more than necessary, and ever and anon retreating panic-stricken, 

 back into the shadow, to renew the attack from an opposite direction, barking 

 huskily. . . . It is wholly out of the question to suppose for a moment that 

 he can have any cause for resentment against the grouse family ; and yet, so 

 universal is this habit of scolding and threatening them on every occasion that 

 I find I have gradually fallen into the way, when shooting grouse, of allowing 

 the squirrels to point out my game for me to a certain extent, finding that 

 three times out of four I can tell from the way they chatter whether or not it 

 is a grouse that excites them at the time. 



A unique case of the relation of squirrel and bird is that recordec^ 

 by Roberts (1922) who saw a titmouse gathering hairs from the tai' 

 of a red squirrel while the latter organ was hanging down from the 

 crotch of a tree. The titmouse " flew down, perched on the trimk 

 beside the tail and gathered herself a mouthful of hairs, the squirrel 

 seeming to pay no attention. At first I thought that the squirrel 

 was dead, but when I started to walk around the tree he kept himself 

 on the other side as usual. The titmouse followed him around, took 



