352 BRITISH BIRDS. 



Family PICID^E, OR WOODPECKERS. 



The Woodpeckers are a well-defined group of birds, and were associated 

 by Forbes with the Kingfishers and Hoopoes, but are placed by Sclater in 

 a suborder by themselves. Like the Kingfishers, Rollers, and Bee-eaters, 

 they have two notches on each side of the posterior margin of the sternum ; 

 but Huxley does not seem to regard them as nearly allied to these families 

 in the modification of their cranial bones, but rather to the Swifts, the 

 Goatsuckers, and the Passerine birds. They exhibit considerable variation 

 in their pterylographic characters, which are said by Nitzsch to resemble 

 those of the Kingfishers in some respects. In their myology and digestive 

 organs they are said to be allied to the Kingfishers and the Hoopoes. 



The Woodpeckers have only one moult in the year, which takes place 

 in autumn, progressing very slowly, so as not to inconvenience the bird. 

 It lasts through July and August frequently into September, and in some 

 species is only completed in October. 



The principal external characters of the Woodpeckers are the long wedge- 

 shaped bill and the distribution of the toes, which are placed two in front 

 and two behind. The wings are rounded, containing ten primaries, and 

 the number of tail-feathers is either ten or twelve. They may be divided 

 into three subfamilies the Picinse, or true Woodpeckers, the Picumninse, 

 or soft-tailed Woodpeckers, and the Yunginse, or Wrynecks, which have 

 also soft tails. The true Woodpeckers may be distinguished by their 

 wedge-shaped tails, the feathers of which are rigid and pointed. Like the 

 Sun-birds and the Humming-birds, the Woodpeckers have a peculiar 

 development of the tongue, which is capable of being extended to a great 

 length, to assist them in catching their prey. 



There are about 330 species of Woodpeckers, which are distributed 

 throughout the world, except that they are absent from Madagascar and the 

 whole of the Australian Region east of Celebes and Flores. Ten species 

 are found in Europe, of which four are British. 



Genus PICUS. 



The genus Picus was recognized by Linnaeus in the 12th edition of his 

 < Systema Nature' (i. p. 173), published in 1766, and, with the exception 

 of the Wryneck, embraced the whole of the then-known Picidse. Unfor- 

 tunately Brisson did not designate any type for his genus Picus, and orni- 



