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PROFESSOR J. COSSAR EWART AND DOROTHY MACKENZIE ON 
and are used , for moulting as well as for the hatching and rearing of young. The 
hatching of young and the moulting of immature and adult King Penguins seem to 
go on during the greater part of the Antarctic summer. According to Murphy, the 
King Penguins assume the adult plumage when about two years old. Though some 
old birds may only begin to moult about the middle of March, young birds, as a rule, 
begin to shed the immature coat early in February. A King Penguin which reached 
the Gardens of the Zoological Society of London in February 1911 underwent a 
complete moult in March, and six months later again moulted.* The majority of 
our British birds moult in the late summer or early autumn after they have recovered 
from the hatching and rearing of their young. Hence the captive King Penguin 
which moulted first in March and then in September, first observed the time devoted 
to moulting by penguins living under natural conditions in South Georgia, and then 
the time usually followed by birds in England. The explanation of this unusual 
procedure is probably that the captive penguin became so completely adapted to its 
new environment during the summer of 1911, that it readily responded in September 
to the stimuli which induce the post-nuptial moult in so many of our British birds. 
That the conditions which prevail in Britain tend to induce imported penguins 
to moult in the autumn is further suggested by a second penguin in the London 
Gardens, and by one of the penguins brought to Scotland in January 1914. The 
former, two years running, moulted in August-September ; the latter moulted in 
October 1914, but in 1915, when better adapted to its new surroundings, it moulted 
early in September. 
Two King Penguins in the Scottish Zoological Park, which moulted in 1914 out 
of the down into the immature plumage, also support the view that acclimatised 
captive birds from the Far South may be expected to moult about the same time 
as our native birds. One of these birds in 1915 began to shed its immature coat 
towards the end of July, the other in the middle of August.! 
(2) Duration of the Moulting Period. 
It was a surprise to ornithologists to learn that the King Penguin, under natural 
conditions, wears its down coat for ten months ; it will be a still greater surprise if 
it is demonstrated that a complete new coat is, as a rule, substituted for the old one 
in ten days. In the case of amphibians and many reptiles the horny layer of the 
skin is completely shed several times a year. If moulting in birds is an inheritance 
from remote reptilian ancestors, it is extremely probable that even in the Cretaceous 
period birds moulted several times a year. At the present day the ptarmigan under- 
goes one complete and two nearly complete moults annually, and in grouse and 
pigeons exchange of feathers takes place during the greater part of the year. The 
* Seth-Smith, Proc. Zool. Soc., 1912. 
f These two young Kings were probably nine or ten months old when they reached Scotland in January 1914, 
and two and a half years old when they assumed the adult plumage in August 1915. 
