THE GREY- AND- YELLOW WAGTAIL- 105 



colour, the back and the rest of the upper surface being of 

 a light ash grey. In winter the two species more nearly 

 assimilate in their colouring, and this circumstance has 

 doubtless been the cause of their hitherto being considered 

 identical, the black back of M. Yarrelli being grey at this 

 season, although not so light as on M. alba. An additional 

 evidence of their being distinct (but which has doubtless 

 contributed to the confusion) is that the female of M. Yarrelli 

 never has the back black as in the male ; this part even in 

 summer being dark grey, in which respect it closely re- 

 sembles the other species. 



Macgillivray says that he is not satisfied as to the dif- 

 ference between the two species, and would not be surprised 

 to find that they are in reality one and the same. * Whe- 

 ther this be the case or not, M. alba of Linnaeus is as 

 much the present species as the preceding, since he refers 

 to Willoughby and Ray, and therefore I think the Pied 

 Wagtail might with propriety be named M. alba, and the 

 grey and white M. cinerea. I have ascertained that the 

 spring moult is complete with the exception of the quills 

 and tail feathers, and not confined to the throat as has been 

 alleged.' 



Leaving this knotty point to be settled by the ornitholo- 

 gists, we will proceed to speak of the two other species. 



THE GREY-AND-YELLOW WAGTAIL (Motacilla Boaruld), 

 sometimes called the Grey, sometimes the Yellow Wagtail, 

 has the head and black blueish grey, tinged with green, the 

 rump greenish yellow, the throat greyish white, and the 

 lower parts bright yellow. A remarkably elegant and 

 beautiful bird this ; not so stout as the Pied species, but 

 a little longer, in consequence of the greater length of the 

 tail ; the male in summer has a black patch on the throat, 

 edged with white bands, so that it looks as if tied on ; it 

 is a partial emigrant, leaving the northern for the southern 

 parts of the country in winter. It is said to be even more 

 aquatic in its habits than the Pied Wagtail, being seldom 

 seen, except about marshy and moist places, and on the 

 banks of streams, &c. ' In such situations,' says Yarrell, 

 1 and somewhat solitary in their habits, a pair of these birds 



