This page has been validated.
Nov., 1922
THE DEVELOPMENT OF YOUNG COSTA HUMMINGBIRDS
193

ject by means of a mirror. She had no fear of the camera, however, and once returned to the nest while my head was under the focusing cloth.

In no case have I seen a male hummingbird in the vicinity of the nest or in any way showing interest in the matter. In fact, all the males had apparently started on their southward migration by the middle of June, 1922, or soon after the eggs had been laid in the last nest and while the young in the second nest were no more than half grown. None was seen earlier than May, probably on account of the lateness of the season, so their stay was very short this year. By July 1 the females and young were also noticeably scarcer. If the owner of the third nest had remained to hatch out and rear her young she would probably have been detained beyond the usual time for migrating.

Despite the small size of the hummingbirds, and of the Costa in particular, the eggs and young as well as the adults must be peculiarly immune to depredations of natural enemies, as evidenced by their survival in the face of several unfavorable conditions brought out in the foregoing notes and which may be enumerated as follows: First, only two eggs are laid and presumably only one brood raised each year by the Costa Hummingbird; second, the period during which the young are confined to the nest is from 50 percent to 100 percent greater than in the case of the smaller passerine species; third, the young are entirely dependent upon the female parent for sustenance. That the hummingbirds are able to maintain their numbers under these handicaps can but increase our admiration for these tiny but highly specialized and intelligent creatures.

Los Angeles, California, August 21, 1922.

EVIDENCE OF MUSICAL "TASTE" IN THE BROWN TOWHEE

By RICHARD HUNT

TO BEGIN WITH I wish to establish in the minds of those readers who do not happen to be familiar with the Brown Towhee (Pipilo crissalis crissalis) a working idea of this bird's song. The song is normally a staccato series of sharp metallic clinks with intervals constantly decreasing so as to carry the utterance into a thrill or vibration toward the end. The "shape" can be easily imagined by thinking of some resilient object, say a golf ball, dropped on a hard surface and allowed to bounce itself motionless, thus: tip         tip       tip   ip-prrrrr. A very good idea of the timbre can be gained by striking together two silver dollars so as to produce a smart and rather "live" ring.

Except in two instances, which I am about to describe, I never was struck by any signs of instability in the Brown Towhee's song. On the contrary I had come to consider the song so stereotyped that it would be absurd to expect any marked individual divergences. "Brownie" had become in my mind a dull fellow, musically, particularly devoid of originality. It was refreshing, therefore, to hear first one and then another individual of the species sing a song that was decidedly "off color"—not, mind you, in any trivial matter of mechanics due to inexperience or adventitious defect of execution, but in what I may call subject matter. Both of these "aberrant" singers that by good fortune came to my notice departed from the type utterance of their race by adding some brand