ROSE-BREASTED GROSBEAK 45 



It is an open question whether blossom eating and budding is harm- 

 ful to the trees or beneficial as proper pruning. 



Behavior. — H. R. Ivor (1944) has studied the behavior of two 

 pairs of rose-breasted grosbeaks in semicaptivity in his aviaries and 

 has published the results of his observations in great detail. His 

 paper is well worth reading. It throws considerable light on the 

 probable behavior of the birds in a wild state, because they were free to 

 come and go and spent some of their time outside the aviary. After 

 the first broods had left the nests, the young birds were cared for by 

 the males, and the females started building their second nests outside 

 the aviary; 13 eggs were hatched in these 4 nests and all 13 young 

 were reared to maturity. 



"When allowed freedom after the first eggs were laid, the birds 

 regularly visited the woods to feed on insects, ceasing almost entirely 

 to use the artificial food provided in the aviary. * * * They found 

 the entrances to the aviary without difiiculty after foraging in the 

 woods." Referring to the word "probable" in the first paragraph 

 above, Ivor wTOte Taber, Aug. 6, 1957, "Over 25 years' experi- 

 menting has shown me that such behavior was normal." 



Voice. — ^Aretas A. Saunders has sent me some elaborate notes on 

 the songs of this bird, from which I quote the following parts: 



"The song of the rose-breasted grosbeak consists of a series of 

 rapid notes, lai'gely connected by liquid consonant sounds, and rarely 

 with two successive notes on the same pitch. It is commonly de- 

 scribed as a warble, but, as groups of notes are separated from each 

 other by very short pauses, it is not so definitely a warble as are some 

 other songs, such as those of the warbling vireo and the purple finch. 

 The quality is very similar to that of the American robin, so much 

 so that many confuse the two songs, though there is a definite differ- 

 ence. It differs from the song of the robin by the much shorter 

 pauses between phrases, so short, in fact, that the song sounds con- 

 tinous, whereas the robin has pauses between the phrases as long as 

 the phrases themselves. Rarely the grosbeak puts longer pauses 

 into its song, and then it sounds much like the robin. I have only 

 two such records, but one other in which the first three phrases were 

 timed like those of the robin, and the other six phrases rapid, hke 

 normal grosbeak songs." 



Saunders states that the length of songs depends in part on the 

 rapidity of the singing, but more on the number of notes or phrases. 

 Notes vary from 10 to 23 per song, averaging 16 in 37 records; phrases 

 vary from 4 to 14, averaging 8}/^. The length of the song varies from 

 2 to 6% seconds, averaging about 3%. Pitch varies from G5 to D7. 

 Pitch intervals range from 23^2 to 6 tones, averaging about 4 tones. 



