PICIDAE 



459 



are hatched. This sound, which can be heard for a mile, is caused 

 by the bill hammering on the bark — usually of some rotten 

 branch, while the bird's head moves backwards and forwards with 

 extraordinary rapidity ; a stationary position, however, is not 

 invariably preserved, nor the quest of food interrupted. The 

 hen sometimes hisses loudly if disturbed upon her eggs ; both 

 parents are said to " purr " in certain American species when 

 the hole is interfered with, and they certainly utter continuous, 

 sharp alarm-notes in Britain. It is probable, but perhaps hardly 

 certain, that the female drums as well as the male. The sense of 

 hearing is extremely acute in the Family. The flight is strong 

 and undulating with constant " dips," and when once witnessed 

 can be recognised at considerable distances. Both sexes help to 

 excavate the hole for their eggs, which is a neat circular aperture, 

 worked from the centre outwards, and carried inwards to the core 

 of the wood, to descend thence for at least a foot ; as soon as it 

 turns downwards it gradually enlarges, until the whole presents 

 the form of a long-necked bottle. Abortive borings are often made, 

 of considerable depth ; while the chips may be found lying at the 

 foot of the tree in a heap, if not removed by the birds, as occasion- 

 ally happens. Firs, oaks, poplars, beeches, ashes, and willows, both 

 high and low, furnish many breeding places, but wooden walls or 

 towers are also utilized, and two species, mentioned below, bore 

 like Kingfishers in banks. The same hole is occasionally tenanted 

 in successive years, but natural cavities are rarely used. It is com- 

 monly stated that Woodpeckers always choose for their excava- 

 tions decayed or decaying limbs; but the soundest branches, or even 

 the thickest parts of the trunks of huge oaks, are not unfrequently 

 selected. The oval, glossy, white eggs are deposited on a few chips, 

 and usually number from three or five to ten; nevertheless as many as 

 seventy-three are recorded as the produce of one Woodpecker, and 

 forty-two in the case of the Wryneck, when robbed on successive 

 days.^ Both sexes are known to incubate in certain cases : they sit 

 very closely towards the end of the period, which lasts fourteen days 

 or more, yet often leave their hole quite readily at first. Many species 

 have been tamed, but they are wild and destructive in captivity. 

 The Family ranges over the greater portion of the globe, except 

 the Australian Eegion, Madagascar, and Egypt. Its members are 



' Mr. Abel Chapman ( TFiM Spain, p. 256) says that the Spanish Green Wood- 

 pecker breeds twice a year ; and its British congener at times does likewise. 



