COAST BUSHTIT 447 



The flock is somewhat scattered, and one cannot tell at first how many 

 birds there are in the company, but they keep in touch with one another 

 as they feed, with gentle twittering notes. They seem to be in con- 

 stant motion as they travel along, hurriedly crossing the open spaces 

 between the bushes, a few at a time, then more and more, all traveling in 

 the same general direction; when 20 or 30 have crossed, and we think 

 that all have gone, there are always a few stragglers hurrying along to 

 catch up with the procession. 



These flocks may consist of anywhere from half a dozen to 20 or 30 

 birds. Dawson (1923) has counted over 70, but usually there are less 

 than 20. And, in winter, they may be accompanied by other small birds 

 that forage with them, such as kinglets, wrens, and chickadees; these 

 birds do not, I believe, follow along in the procession of bushtits. 



Dr. Joseph Grinnell (1903) writes of the behavior of these flocks: 



During such slowly moving excursions, each individual is rapidly gleaning 

 through the foliage, assuming all possible attitudes in its search for tiny 

 insects among leaves and twigs. ♦ * * At times, especially towards evening, 

 the flocks become more restless and move along from bush to bush and tree to 

 tree much more rapidly than when feeding, the birds straggling hurriedly after 

 each other in irregular succession. During these hurried cross-country ex- 

 cursions, the simple location-notes are pronounced louder and are interlarded at 

 frequent intervals with a shrill quavering note. The faster the band travels, the 

 louder and more oft-repeated becomes these all-important location-notes ; for the 

 greater becomes the danger of individuals becoming separated from the main 

 flock. Bush-tits are usually hidden from each other in dense foliage. They have 

 no directive color-marks; therefore, being gregarious birds, the great value of 

 their location-notes becomes apparent 



Should a bush-tit lag far behind as to be beyond hearing of his fellows, he 

 may suddenly come to a realization of his loneliness; he at once becomes greatly 

 perturbed, flitting to the tallest available perch, and uttering the last mentioned note 

 reinforced into a regular cry for his companions. This is usually heard by the 

 distant band and several similar answering cries inform the laggard of the direc- 

 tion the flock has taken. Off he goes in zigzag precipitatisn and joins his fellows 

 with evident relief. 



He describes a peculiar behavior, also noted by others, that is evi- 

 dently effective as a protective device: 



A flock of bush-tits will be foraging as usual, with the ordinary uncertain 

 medley of location-notes, when suddenly one or two birds utter several of the sharp 

 alarm notes and then begin a shrill quavering piping. This is taken up by the 

 whole flock, until there is a continuous monotonous chorus. At the same time 

 every member of the scattered company strikes a stationary attitude in just the 

 position it was when the alarm was first sounded, and this attitude is maintained 

 until the danger is past. In nearly every case the danger is in the shape of a 

 hawk, more especially of the smaller species such as the sharp-shinned or sparrow 

 hawks. No matter how close the hawk approaches, the shrill chorus continues 



