October 4, 1901.] 



SCIENCE. 



525 



I could generally, during the height of 

 the song season, start the birds to sing by 

 going to their cages, speaking to them and 

 whistling a few notes. Here it seems essen- 

 tial to emphasize the fact that I in no way 

 trained them to sing and made no effort to 

 start them in song till long after their 

 method of singing was established. In 

 fact, the quality and phrasing of their 

 singing was of such a character that 

 none save an expert whistler could re- 

 produce it. 



Early in May of 1896 I took the birds to 

 the country near New York, where we re- 

 mained until July 20, 1897, a period of 

 some fourteen months ; then I moved to 

 Princeton, New Jersey, where the remainder 

 of their lives was passed. Both birds died 

 during the winter of 1899-1900, apparently 

 of old age. 



To go back to the time of departure 

 from New York in the spring of 1896. As 

 has been stated, the birds' song became less 

 frequent by the first week in May, and by 

 the twentieth of that month they had 

 ceased to sing. On June 6 I noticed the 

 first signs of the summer moult and in a 

 very few days it was in full progress. 



It may be well to indicate some of the 

 details of the change, though this is a di- 

 vergence from the chief subject. Also, it 

 should be borne in mind that native birds 

 kept in confinement are generally about a 

 month earlier in moulting and also in the 

 song season, than are the representatives of 

 the same species at liberty out of doors. 

 This applies to all the species I have kept 

 in confinement and when the birds are per- 

 fectly normal and healthy — so sound in 

 health as to breed in captivity, which seems a 

 good criterion. As examples, I may men- 

 tion the bluebird (S. sialis), robin (ilf. mi- 

 gratoria), wood thrush (H. mustelina), cat- 

 bird ((r. carolinensis) , brown thrasher (H. 

 rufus), and the orchard oriole (I. sjiurius), 

 all of which I have had live and breed and 



go through the song and moult seasons 

 year after j^ear in captivity. 



The moulting period of the two orioles 

 occupied a month, and early in July both 

 were in most exquisite fall plumage. The 

 deeper orange and rusty tint that is so char- 

 acteristic of the species, and the suffusion 

 of the black areas on the throat, were as 

 marked and fine in detail as in wild birds. 

 At this moult for the first time the larger 

 wing and all the tail feathers were shed and 

 replaced. The two birds were marvels of 

 beauty at all times, but just after the full 

 summer moult they filled those who saw 

 them with admiration and wonder. After 

 the moult there was a secondary song sea- 

 son of short duration. The song was of the 

 same character, but not so prolonged or 

 elaborate. 



So I have endeavored to give an idea of 

 a year, or rather more, of these birds' lives, 

 and the succeeding years to the end were 

 but repetitions with but slight variation. 



Each year the wearing of the tips of the 

 feathers was apparent in January, and a 

 partial moult such as I have described took 

 place late in that month or in February. 

 Then began again the peculiar low soft song 

 at infrequent intervals, presently becom- 

 ing noticeable in volume and occurrence, 

 till the song wave reached its height and 

 died away. Each early June found the 

 birds putting on an entirely new garment 

 of feathers. 



I have spoken before in this paper of the 

 observations of a second generation. I 

 find that this perhaps convej's a wrong im- 

 pression. Let me saj' at once that the 

 second generation consisted of a brood of 

 young orioles in no way related to Timmy 

 or Driver, However, for the purpose of 

 my subject, really these were a second gen- 

 eration, of birds of a given kind, subject to 

 the influence of older birds of their own 

 species. 



On June 15, 1897, when Timmy and 



