A BIRD WITH A LANGUAGE 



JOSEPH GRINNELIi 

 Professor of Biologry, Throop Polytechnic Institute 



OF the many peculiarly Western species of birds, I can think of none 

 more attractive for study than the California bushtit (Psaltriparus 

 minimus), which ranges commonly throughout the whole length 

 of the State, west of the Sierras. This bird's nearest relative in 

 the East is the chickadee; but one would hardly guess this by either color- 

 ation, habits, or notes. As the second part of its scientific name implies, 

 the bushtit is an extremely small bird. Of the trifle more than four inches 

 of total length, fully half is appropriated by the tail. But this long tail is 

 not held vertically over the back, as with the wrens. In color the bushtit 

 is a very plain grayish brown all over, without any of the contrasted black 

 and white which renders the chickadee easy of recognition. 



During three fourths of the year the California bushtits forage about 

 in flocks. These bands may consist of as many as thirty individuals, 

 but generally there are from fifteen to twenty. Although we call them 

 "flocks," they are not so in the sense that blackbirds or linnets form flocks; 

 for the bushtits never bunch together and mount high in air to take a 

 prolonged flight, but they form a loitering company, scattered among 

 several scrub-oaks or brush-clumps. There may be a general onward move- 

 ment; for if a person locates himself in the midst of the restless drove, in 

 a few minutes they will have almost all gone off in some particular direction. 

 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 excursions the 

 simple location-notes are pronounced louder, and are interlarded at frequent 

 intervals with a shrill quavering note. Should a bushtit lag so far behind 

 as to be out of hearing of his fellows, he may suddenly come to the reali- 

 zation of his loneliness; he at once becomes greatly perturbed, flitting to 

 the tallest available perch, and uttering the last-mentioned note re-enforced 

 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. 



A flock of bushtits will be foraging as usual, with the ordinary uncer- 

 tain 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, and even inten- 

 sifies, until the enemy has passed. The remarkable thing about this united 

 cry is that it is absolutely impossible to locate any single one of the birds 

 by it. The chorus forms an indefinably confusing, all-pervading sound, 

 which I know from personal experience to be most elusive. It may be 

 compared in this respect to the cicada. This confusion-chorus, as I think 

 it might be appropriately called, is a sure sign of the appearance of a small 

 hawk even a long way off. Often long before I could myself locate the 

 hawk, a neighboring band of bushtits would have set up their cry, thus 

 announcing its approach. It seems reasonable to infer that this monoto- 

 nous chorus of uncertain direction, at the same time that it sounds a 

 general alarm, serves to conceal the individual birds, all of which maintain 

 a statuesque, motionless attitude. Their colors also harmonize closely 

 with the shadows of the foliage. The whole evidently forms a composite 

 protective device, which must be, as a rule, effectual. 



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