BIRDS. 



Ill 



Chile these birds are migratory ; they make their appearance there in autumn ; 

 the first arrival which I observed was on the 14th of April (corresponding to our 

 October) but by the 20th they were numerous. They stay throughout the winter, 

 and begin to disappear in September : on October 12th, in the course of a long 

 walk, I saw only one individual. During the period of their summer migration, 

 nests were very common in Chiloe and the Chonos Island, countries south of 

 Chile. When this species of Trochilus migrates southward, it is replaced in Chile 

 by a larger kind, which will be presently described. The migration of the 

 humming birds on both the east* and west coasts of North America, exactly 

 corresponds to that which takes place in the southern half of the continent. In 

 both they move towards the tropic during the colder parts of the year, and retreat 

 poleward before the returning heat. Some, however, remain during the whole 

 year in Tierra del Fuego ; and in northern California, — which in the northern 

 hemisphere, has this same relative position which Tierra del Fuego has in the 

 southern,— some, according to Beechey, likewise remain. Near the south end of 

 Chiloe, I found on the 8th of December, a nest with eggs nearly hatched. It was 

 of the ordinary form of nests ; rather more than an inch in internal diameter, and 

 not deep, composed externally of coarse and fine moss, neatly woven together, 

 and lined with dried confervse, now forming a very fine reddish fibrous mass. 

 I feel no doubt regarding the nature of this latter substance, as the transverse 

 septa are yet quite distinct : hence this humming bird builds its nest entirely 

 of cryptogamic plants. Egg perfectly white, elongated, or rather almost 

 cylindrical, with rounded ends ; length -557 of an inch, and transverse diameter 

 •352 of an inch. In January, at the Chonos Islands, when there were young in 

 the nest, a considerable number of old birds were shot ; of these, however, few or 

 scarcely any had the shining crest of the male. In the only specimen, which I 

 carefully examined, the metallic tips of the young feathers of the crest, were just 

 beginning to protrude. Several of these males without their crest, had a yellowish 

 gorge ; and I saw some with a few light brown feathers on their backs. I 

 presume these appearances are connected with their state of moult. 



3. Trochilus Gigas, Vieill. 



Orsimya tristis, Less., Oiseaux Mouches, pi. 3. 



This species is common in central Chile. It is a large bird for the delicate 

 family to which it belongs. At Valparaiso, in the year 1834, I saw several of 

 these birds in the middle of August, and I was informed they had only lately 

 arrived from the parched deserts of the north. Towards the middle of September 



* Humboldt, Pers. Narr. vol. v. part 1. p. 352. Cook's Third Voyage, vol. ii. and Beechey 's Voyage. 



