The Accentorinae or Accentors comprise a number of birds the position of which has been much disputed. Looking to their habits and to the colour of the nestling, their position appears to me to be among the Thrushes.
The Accentors have a bill about half the length of the head, wide at base, compressed somewhat abruptly in the middle, the culmen nearly straight, the upper mandible terminating in rather a fine point and slightly notched; the nostrils large, diagonal, and covered by a large membrane ; the rictal bristles few and weak ; the feathers of the forehead slightly disintegrated ; the tail nearly square or sometimes slightly forked ; the tarsus strongly scutellated.
The sexes are alike, and some species have a seasonal change of plumage caused by the wearing away, in winter, of the margins of the feathers. The young moult into adult plumage at the first autumn. The nestlings of the various species resemble each other closely, and may be described as pale rufous below, densely streaked with dark brown, especially on the breast and sides of the body, the chin being frequently barred. The upper plumage is dark brown, each feather edged with rufous.
The majority of the Accentors inhabit mountains at considerable elevations; others, like the common Accentor or Hedge-Sparrow of England, inhabit gardens and cultivated spots. They feed on insects, and also, it is said, on small seeds. They build their nests in bushes or in holes of rocks, and lay blue eggs.
Key to the Genera.
a. Wing large and pointed, longer than tail by more than length of tarsus……………………ACCENTOR, p. 166.
b. Wing small and blunt, longer than tail by much less than length of tarsus……………………THARRHALEUS, p. 168.