VI 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 earried 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 
hke 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 Region, Madagascar, and Egypt. Its members are 
1 Mr. Abel Chapman (Wild Spain, p. 256) says that the Spanish Green Wood- 
pecker breeds twice a year; and its British congener at times does likewise. 
