244 BULLETIN 197, UNITED STATES NATIONAL MUSEUM 



by Henry W. Carriger near Sonoma, Calif., that came from a nest 

 about 16 feet from the ground in a laurel ; it was apparently of usual 

 construction, but was said to have been lined with fine grasses, a few 

 feathers, and a little hair. 



Mr. Dawson (1923) gives the following good description of a 

 Hutton's vireo's nest: "An example before me is a three-quarter 

 sphere composed of sycamore down, and the familiar gray-green 

 usnea (a lichen, of course, but we all call it 'moss') lashed together 

 with cobwebs. The edges are made fast to forking twigs of live oak, 

 and are exquisitely rounded, while a convenient twig below supports 

 the bottom of the nest in graceful security. The nesting hollow, al- 

 most as deep as it is wide, is daintily lined with the finest of dried 

 grasses. Its dimensions are three inches in width by two and three- 

 quarters in depth, outside ; and two and three-eighths in width by one 

 and three-quarters in depth inside." 



Mr. Eathbun mentions in his notes a nest found by D. E. Brown, 

 in Pierce County, Wash., that "was 6 feet above the ground and at- 

 tached to the end of a somewhat drooping branch of a spirea." 



Eggs. — The Hutton's vireo's set usually consists of four eggs, some- 

 times only three, and very rarely five. The usual shape is ovate, but 

 some eggs are slightly more pointed and some a little more elongated. 

 The shell is smooth but without gloss. They are x)ure white and 

 rather sparingly marked with a few small spots or fine dots, mostly 

 near the larger end, of dark or light browns, or reddish brown. Some 

 eggs appear to be nearly spotless. 



The measurements of 40 eggs average 18.0 by 13.2 millimeters; the 

 eggs showing the four extremes measure 20.0 by 14.2, 17.0 by 12.5, 

 and 17.5 by 12.0 millimeters. 



Young.— My. Van Fleet (1919) writes: 



Incubation is performed by both parents, and it is during this period that 

 they are most wary against the detection of their treasures. I have seen 

 one bird dive into the nesting tree, make the change at the nest and the other 

 bird leave, so rapidly, that it seemed as though but the one bird had entered 

 and left the tree. * * * About two weeks after incubation is started the 

 nestlings are hatched and by the time the month is out they are ready to take 

 their first trials of flight. The nestlings are fed by both parents during their 

 stay in the nest. I watched four fledglings being fed for a period of about an 

 hour; they were visited every five minutes on an average during this period. 

 The nestlings were partially covered with feathers at the time and were keep- 

 ing the parents very busy filling their hungry mouths. 



Mrs. Whcelock (1904) says that the young "are fed by regurgitation 

 for five days and, after that, the food is usually reduced to pulp before 

 being given to them. It consists almost entirely of small tree-worms, 

 green and white, the latter sometimes seeming, by their whiteness, to 

 be fruit worms. The intervals between feeding are unusually short, 

 ranging from three minutes to half an hour." 



