104 BULLETIN 196, UNITED STATES NATIONAL MUSEUM 



then reactions varied greatly. Sometimes other wood thrushes were 

 driven out, but at other times they were not. Sometimes the male 

 would challenge the intruder with a burst of his most complete song, 

 which would last as long as 10 minutes. On other occasions the 

 intruder was merely chased from the territory. Most robins were 

 chased, but some were not. All degrees of alarm and retaliation 

 were displayed from the mildest form, in which the adult sat quietly 

 and merely raised the feathers on the head, to a real bird fight. When 

 the young in one nest were 10 and 11 days old, the male fought the 

 most furious fight I have ever witnessed. He flew upward attacking 

 the robin in the air. The two birds flew at each other with wings 

 beating rapidly and feathers fluffed from the body. They attacked 

 each other over and over again, and peace was not restored until 

 the robin was chased from the territory. A veery chased two wood 

 thrushes from its territory in an area containing five wood-thrush 

 nests. A scarlet tanager was attracted by the call of a young wood 

 thrush when it was just a day out of the nest. The tanager flew away 

 unchallenged while another wood thrush, which alighted on the same 

 branch as had the tanager, was driven out. Brackbill (1943) notes 

 that the territory was defended against other wood thrushes but that 

 the birds seemed very tolerant of other species. He says the only 

 birds toward which they displayed hostility were a blue jay and a 

 purple grackle. 



The males arrive first on the breeding grounds, as the records of 

 Cornell University show that the first wood thrushes reported for 12 

 different seasons were singing birds. In one instance the female of 

 a pair arrived in the territory three days after the male. Early in 

 the morning the male bird sat high up in a leafless tree singing. A 

 low trrrr, which I have often heard both male and female give as if in 

 acknowledgment of its presence, could be heard. There was a sudden 

 flight to the ground. This was followed by six or seven swift, circular 

 flights of about 30 feet in diameter, one bird in pursuit of the other. 

 They both alighted contentedly in the same shrub and began feeding 

 among the fresh leaves. This circular flight was accompanied by 

 swift turnings to bank with the curve. A few low notes were uttered 

 during this performance. Four days later the song of the male in 

 this territory was noticeably loud and long. Loud calls of excitement 

 were also heard, leading me to believe that the territory was 

 well established. Another observation of a similar performance 

 was made. The female stood on a low branch and fluffed her feathers 

 and raised her wings. The male chased her in half a dozen circular 

 flights. Between flights both birds fed among the fresh leaves, often 

 biting off pieces which fell to the ground. In this case the female 

 arrived six days after the male. He used the very highest tree in the 



