174 THE TITMOUSE FAMILY 



nppearance ; still llicy offer certain general characteristics 

 which do not allow us to have the slightest doubt about 

 their common parentage. They all have a short, cone- 

 shaped bill which is slightly flattened on the sides and 

 covered up to the nostrils with small feathei's which bristle 

 easily and give an impertinent expression to their physiog- 

 nomy. All titmice too have very robust muscles in the neck; 

 their skull is very thick; they also have much strength in 

 the muscles of their feel and toes ; this explains the supple- 

 ness and agility of their wonderful gymnastic feats, when 

 they destroy caterpillars on the branches, pick hard seeds 

 and pierce the shell of hazelnuts. It has even been said 

 that they lake atlvanlage of the sharpness of their bill, 

 which can be compared to a blade of steel, in order to 

 pierce the skulls of small birds when they find them either 

 dead or weakened by illness, so as to feast on their brains. 

 Ordinarily however, titmice are satisfied w^ith more inno- 

 cent food ; lliey live chiefly on cater])illars, eggs of butter- 

 flies, but also on hazelnuts, beech-nuts, walnuts, and in 

 general on all kinds of oil-seed. 



Diirini^- the fine season they live in the depths of 

 hillv woods, but as soon as the first cold sets in and 

 I he first snow falls on the mountains, they emigrate to- 

 wards cultivated plains and draw nearer to inhabited re- 

 gions. Nearly all titmice are remarkable for their talent 

 in nest-building, which is truly extraordinary in such 

 small birds. They employ in the construction of their 



