GAMBEL'S WREN-TIT 83 



male joining a male that has, or is establishing himself on, a territory. 

 Two birds of the year, which I believe are a male and a female, are 

 often seen together during fall and winter, but these seem to be transi- 

 tory attachments, and the female will leave such a male to join an 

 established one. 



I once observed what appeared to be the establishment of a male 

 on a territory and his acquisition of a mate. In a patch of brush 

 that had not been occupied on the previous days, a young banded male 

 was observed in the morning between 7 :30 and 9 o'clock. During this 

 time he went from the upper end to the lower and back to the upper, 

 and except for a few brief intervals sang on an average of 5 times a 

 minute — approximately 450 utterances. Wlien he was at the top the 

 second time, his calls were low and of poor carrying quality, but here 

 a second wrentit was heard and glimpsed for the first time. The two 

 moved down the the slope again. I heard no sounds except a single 

 song and a lirTT answer, but low notes would not have reached me. 

 About 9 :30 the pair were lost in the lower part of the territory. At 

 11 :30 I looked for them again and found them behaving as any es- 

 tablished pair would behave. 



What actions take place as the pair first meet were never seen in 

 the field. When a female was put into a cage containing two males 

 and a female, the subsequent rapid movements of the four birds were 

 exceedingly difficult to follow. The actions of the original female 

 were mainly hostile. Lightning advances and retreats occurred be- 

 tween the two males and the new female, accompanied by a variety of 

 soft musical and harsh notes as well as those common during disputes. 

 The frequency of these chases decreased markedly by the end of the 

 day, and soon the new female acted as the typical mate of one of the 

 males. 



Most of the time there is little activity to indicate that two birds 

 are mates except their constant companionship. They forage to- 

 gether, they frequently preen each other, they rest on the same perch 

 during the day, and they roost together at night. Their interest in 

 each other moves toward a peak, as shown by sexual flight and special 

 versions of the song as they build the nest, and it reaches its climax 

 in coition on the days the nest is lined. In sexual flight the female 

 continually hops or flies away from the male as he approaches, so that 

 a rapid chase takes place. Posturing was never observed, but it may 

 occur, since it would be difficult to observe it. 



Once mated, the pair remain together as long as both are alive. Of 

 the pairs I knew, five existed at least three years and a sixth for 2i^ 

 years. Six pairs were together for 2 years and may have existed prior 

 to or after my knowledge of them. Only five pairs were known to have 

 lasted only 1 year. Wlien a pair was broken up, one or both members 



