SAN FRANCISCO BROWN TOWHEE 611 



main room of the Museum. By IMay 25 the attacks had nearly ceased, but after 

 this date they increased again at our windows until on June 24 they were about 

 as vigorous as ever. Subsequently they dwindled again to cease finally after 

 July 14. On September 23, and for a few days subsequent to it more attacks 

 occurred. 



An explanation of the variation in the amount of activity was easy to disco\er. 

 During the first period of increasing activity the fighting bird always accompanied 

 its mate to the window. Their appearance at the window ledge was always 

 heralded by a medley of mewing and squeaking notes from the oak tree outside 

 the window. While the female fed busily the male would fight the window. 

 The birds would usually fly into the oak tree where the female would sometimes 

 preen awhile, but in a short time the female would fly to the west and disappear 

 among the trees bordering Strawberry Creek. The male always closely accom- 

 panied the female. In a short time the male would return to the window to 

 fight. The actions of the pair, and the presence of brood patches on the female, 

 led to the belief that the female was incubating, but it appeared that the male 

 was taking little if any part in the incubation other than guarding the fe- 

 male. * * * 



It is clearly apparent from the above description that shadow 

 boxing is intimately connected with breeding and defense of territory. 

 The authors fm'ther point out that the attacks dropped off during the 

 feeding of the young and increased again with the second brood. 



E. I. Dyer (1931) observed four or five brown towhees respond to 

 the distress calls of rufous-sided towhees when he approached too 

 closely to their nest. 



Voice. — Just as uninspiring as its plumage is the voice of the brown 

 towhee. With care, however, it is possible to distinguish many 

 variations of the basic chip note and to interpret the meanings of 

 these variations. Indeed, to understand the mechanics of the species' 

 population biology, one must become acquainted with its metallic 

 clatter song. C. W. Quaintance (1938, 1941) has reported at length 

 on the voice of the brown towhee and in the main this discussion comes 

 from his work. 



The basic note of the brown towhee's vocabulary is a metallic chip 

 or tsip, often repeated with monotonous regularity, sometimes as fast 

 as 30 per minute for 25 minutes at a time. Quaintance (1941) thus 

 describes the use of this note : 



The tsip note is not necessarily correlated with activity, although it does an- 

 nounce the beginning of activity in the early mornings and again, the cessation 

 of activity in the evenings before the towhees go to roost. On the other hand a 

 towhee may tsip for fifteen minutes without any activity. In flight it may give 

 several tsips or none at all. An emphatic tsip may announce the take-off, and a 

 tsip or two may be giv en upon alighting from a flight. A towhee may tsip on the 

 ground while it is foraging, or it may forage for minutes without giving a sound. 

 Frequently, in the nesting season, the tsiping is done from a high station such as 

 the top of a laurel tree, or thirty or forty feet up in a eucalyptus, or from the peak 

 of the highest available house or telephone pole. 



