Moulting of Birds 83 



costume, worn and battered with long service in the nesting 

 and bringing up of the young, and by the time that they 

 have effected their retreat to their winter home in Africa, 

 they are scarcely recognizable as the brilliant little birds 

 which come to us in the spring. The blue plumage is 

 worn and bleached to a dull brown, the red on the forehead 

 and throat become white, and the flight-feathers and those 

 of the tail are worn out and jagged. Some specimens 

 killed in the late autumn in England, show here and there 

 a feather in process of renewal by moult, but as a rule all 

 the Swallows commence their moult in December, when 

 they are far from Europe, and it is not until February that 

 they have gained their new and beautiful plumage, when 

 they at once begin their journey northward. 



Many birds seem to be always more or less in moult, 

 notably Gulls and Birds of Prey, and it is interesting to 

 see that complete correspondence in the shedding of the 

 wing-feathers takes place, so that if the sixth primary is 

 being renewed on one wing, it will be found that the same 

 primary is also in process of renewal on the other wing. 

 But besides this regularity of moulting as the means of 

 the renewal of plumage, there are certain exceptions to the 

 general rule that all feathers are renewed by an absolute 

 casting of the plume. Take, for instance, Redstarts, Buntings, 

 and some of the Finches — there being no better example 

 than our House-Sparrow {Passer domesticus) of a change of 

 plumage without moult. In the autumn after the Cock 

 Sparrow has renewed his feathers and put on his winter dress, 

 he presents a much duller and browner appearance than he 

 does in the perky plumage of the summer. The gi'ey head 

 appears brown, of the black throat there is no trace, ex 

 cepting perhaps on the chin, and yet our little friend will 

 put on his perfect dress in the following spring without 

 casting a single feather. The light edgings to the plumes, 

 which hide the grey colour of the head and the black of 



