576 ANIMAL LIFE IN THE YO SEMITE 



Terminal twigs, newly opened foliage and moss-covered trunks seemed 

 to be inspected with equal interest. If the upper side of a twig did not 

 yield food the bird would hang inverted to scrutinize the lower surface, 

 seeming to be quite as much at ease in this reversed position. Most inter- 

 esting was the way in which the chickadees explored cavities. A bird 

 would disappear into some hollow left by the rotting out of a stub, scan 

 the interior for a few seconds, come to the opening and look about for 

 possible danger, then disappear inside again. It would continue this 

 performance until the cavity had been examined throughout. Occasionally 

 one of the chickadees would drop into a manzanita bush, and twice the 

 birds alighted on the ground for a short while. 



The chickadee is ceaselessly active, in large part from necessity, we 

 suppose, for a bird must cover much territory each day to get the requisite 

 amount of daily bread. The birds, although intent in their search, are 

 alert for anything out of the ordinary. They have a large bump of curi- 

 osity, and any unusual sight or sound will bring them to the point of 

 interest in. a hurry. If a person will sit down at the foot of a fir tree, 

 well screened by the canopy of drooping boughs, and 'screep' with lips 

 to back of hand, he will soon have, literally at arm's length, a number 

 of chickadees. The birds at first are excited and call frequently as they 

 hop and flutter from branch to branch. Then, after some moments of 

 intent peering, they move away quietly, and resume their usual occupation. 



The Mountain Chickadee shows considerable range in vocal powers, 

 hardly to be guessed on first acquaintance. The usual call note is the one 

 popularly rendered as chick-a-dee-dee, but with an asthmatic, wheezy inton- 

 ation ; often it is reduced to simply chee-chce-chee. Sudden surprise is 

 evinced by an explosive tsick'-a, repeated several times. On sharp morn- 

 ings when the birds congregate on the sunny sides of the columnar fir trees, 

 they often indulge in a chorus of cheerful notes, each group of sounds a 

 jumble of sibilants impossible to syllabify and interspersed with the ordi- 

 nary calls. In addition there is what we consider the real song, a strik- 

 ingly clear, far-carrying, whistled, tee-tee, too-too. The two pairs of notes 

 are on different pitches, higher and lower, respectively. Frequently the 

 second note of the first pair is omitted and the remaining note prolonged : 

 tee; too-too. The song is given in winter as well as in spring and summer. 

 It is one of the easiest remembered of Sierran voices, and one that a person 

 can readily imitate by whistling. 



In the spring months the chickadees, then foraging in pairs, will be 

 seen to indulge in some of the features of courting behavior exhibited by 

 other birds. At times one of a pair (probably the female) will quiver 

 her wings, whereupon the other will feed her, at the same time holding 

 his tail slightly spread. Now and then a bird which has been calling will 



