390 SINGING BIRDS. 
Like the Creepers and Nuthatches, these birds are seldom 
seen to perch upon the branches of trees, but creep spirally 
around the trunk and larger boughs up and down, in quest of 
insects which alight upon or hide within the crevices of the 
bark. In this employment they display all the dexterity of the 
more regular climbers. For this purpose the hind toe is rather 
stout, and extends backward so as to balance with the anterior 
part of the foot, and allow a motion like that of the Creepers, 
from which genus they are at the same time wholly distinct. 
At the period of breeding, the male scrapes out a little 
monotonous ditty in recognition of his mate, resembling some- 
what the syllables ze ¢she tshe tshe tsh' tsheté, proceeding from 
high to low in a tolerably strong and shrill, but somewhat 
filing tone. As the season of incubation advances, this note, 
however, becomes more mellow and warbling, and though 
feeble, is very pleasing, bearing at this time some resemblance 
to that of the Redstart (Setophaga ruticilla). This song is like 
the ascending call of "twee "twee ’twee ’twee tweet. At the 
romantic estate of the Cold Spring place in Roxbury the pro- 
prietor, Mr. Newman, pointed out to me the nest of this bird, 
which on the 27th of June contained four young about a week 
old. Other birds of this species I had seen fledged this year 
about the 17th of the same month, and as Wilson remarks the 
flight of the young in July, we may suppose that they raise two 
broods in the season. The nest was niched in the shelving of 
a rock on the surface of the ground, and was externally com- 
posed of coarse strips of the inner bark of the hemlock-trees, 
which overshadowed the situation. With these were mixed soft, 
dissected old leaves and a few stalks of dead grass; the lining 
was made of a thin layer of black hair. According to Audu- 
bon, these birds nest in Louisiana in some small hole in a tree, 
and employ dry moss and a lining of downy substances. The 
pair fed the young before us with affectionate attention, and 
did not seem more uneasy at our presence than the common 
and familiar summer Yellow Bird. They crept about the trunks 
of the neighboring trees, often head downwards, like the Sittas, 
and carried large smooth caterpillars to their young. This is, 
