DIVERS, GREBES, AND CORMORANTS. 165 



and functionless tail, and dense compact plumage 

 of a peculiar silky texture. The twenty or so 

 species of Grebes are grouped into a single family, 

 called Podicipedidae, of which the genus Podiceps 

 (or more correctly Podicipes] contains the greater 

 number. The Grebes are almost cosmopolitan. 

 Five well-marked species are found in Europe, all 

 of which, being visitants or regular residents, are 

 included in the British avifauna. In the colours 

 of their plumage the Grebes are not very remark- 

 able, with the exception of the crests or tippets 

 assumed by some species during the nuptial period : 

 plain browns predominate on the upper surface ; 

 the underparts are almost always glossy white. 

 The Grebes fly well ; dive with great dexterity, but 

 their movements on the ground are not graceful. 

 The young are hatched covered with close down, 

 and able to swim at once. The Grebes have a 

 complete moult in autumn, and assume their nuptial 

 ornaments in spring. The quill feathers are moulted 

 so rapidly that for some little time the birds are 

 unable to fly, as is the case with the Geese and 

 some others. 



It is only during the winter months that 

 the Grebes become pelagic or marine in their 

 habits, and even some species are much less 

 addicted to a sea life than others. We will 

 now proceed briefly to glance at the British 

 species. 



