THE CREEPERS. 469 
by an arched beak and a stiff tapering tail. The family compre- 
hends several genera and sub-genera, of which the principal are 
the Creepers (Certhia), properly so called, the Wall Creepers ( Zzcho- 
droma), the Piculets (Picumnus), the Oven Birds (/urnarius), the 
Thornbills (2amphomicron), the Sun Birds (Vectarina), and the Nut- 
hatches (.Sz/¢a). 
The Creepers (Certiza) are small climbing birds which live and 
build their nests in the holes they bore in the trunks or in the natural 
Fig 189.—Oven Birds. 
hollows of trees: the insects to be found under the bark being their 
food. Looking at the form of their slender beak, it is difficult to 
imagine how it can penetrate the hard covering of an oak, for which 
they exhibit a marked preference. The Common ‘Tree Creeper 
(Certhia familiaris, Fig. 188) is spread over nearly every European 
country, and is very common in France. The Wall Creeper ( Zicho- 
droma murarius), called also Wall Climber (the grimpereau des 
murailles of French authors), owes its name to its habit of climbing 
the walls of dwellings. Supporting-points are not found in their 
tails, as in the Woodpeckers. Grasping the tree with their claws, 
they assist their feet by a slight movement of the wings. They feed 
on insects, and lead a solitary life on the mountains, only descending 
