224 THE BIRDS OF SHERWOOD FOREST. 
of October, and generally leaving in March ; but I have 
known them prolong their stay until April—once, in-. 
deed, in 1854, I noted a flock of eighteen on Thoresby 
Lake so late as May 1]. 
The plumage of both the male and female goosander: 
is very handsome, though so different that it is no 
wonder that fora long time, as in the similar case of the 
hen-harrier and ringtail, they were classed as distinct 
species, the female being known as the dun diver, and 
receiving the specific name of castor. This confusion 
of the sexes has, however, long since been cleared up by 
dissection, the anatomical peculiarities of the trachea 
being alike in both. I have myself frequently noticed 
amorous passages to take place between the goosander 
and the dun diver whilst on the water. 
The contrast in the plumage of the male, between the 
black of the head and back and the rosy cream-colour 
of the neck and breast, is exceedingly striking, and 
though less obtrusive, the reddish-brown of the head and 
neck of the female, with the bluish-grey of the back, 
offers almost as pleasing a distinction. 
The plumage of the young males is so exactly the 
same as that of the female, that until after their first 
moult it is impossible to distinguish them ; yet they do 
not asstime the full adult livery at once, as I have seen 
several in which the dark feathers of the head were in- 
terspersed with brown ones, the lower part of the neck 
and the breast being also mottled with ash colour. The 
pendant crest of both males and females adds greatly to 
their beauty; that of the former is looser in texture, 
and hangs more gracefully than that of the female, which, 
though of equal length, is narrower, and thicker at the 
upper part. 
