BRITAIN'S BIRDS AND THEIR NESTS. 19 



perhaps more for warmth than concealment. In fact, the 

 nest is a mass of decomposing vegetable matter, and 

 therefore evolves a considerable amoimt of heat. The 

 temperature of the nest reaches 73° F. at times, and this 

 explains how the birds can leave their eggs for half-a- 

 dozen hours without ill effect. Both parents take their 

 share in the duties of incubation. The chicks are covered 

 with thick down, and are active from the first, taking to 

 the water almost at once. In fact, while one parent is 

 engaged in hatching the remaining eggs, the first one 

 or two chicks are already spending most of their time 

 swimming about under the guardianship of the other. 

 When the old bird swims off rapidly on some alarm, the 

 chicks attach themselves by their bills to some part of its 

 plumage. At other times the chicks clamber on to their 

 parent's back for a rest, or, for the same purpose, are 

 brought back to the nest ; but this is finally forsaken 

 almost immediately after the last egg has been hatched. 

 Two broods, however, are said to be sometimes reared 

 in a season, the young of the first brood being driven 

 away to shift for themselves before the second laying 

 begins. 



The down plumage of the yoimg Grebe is very remark- 

 able on account of a bright-red, triangular patch of bare 

 skin on the crown of the head and the characteristic 

 tiger-like stripes. These are alternate stripes of black 

 and yellow, which run longitudinally the whole length of 

 the body, and even show themselves latitudinally on the 

 bill. They are confined to the upper-parts, the under- 

 parts being of a more uniform pale colour. 



A curious habit possessed by this and other Grebes is 

 that of swallowing their own feathers, apparently to serve 

 a similar purpose to that of the small stones, and so on, 

 swallowed by most birds. These feathers are often put 



