TREE-TRUNK BIRDS 179 
“These birds not only make their nests in the wood 
itself by hollowing out partly decayed places in branch 
and trunk, but they gain the greater part of their food 
by searching the cracks in the tree bark for insects that 
live there, and which other birds, that spend their lives 
among the leafy twigs, cannot find. 
“This quarrying food from the bark makes it possible 
for them to stay about the vicinity of their nesting-haunts 
all winter; for many forms of insect life winter in the 
bark crevices of forest as well as fruit trees where the 
eggs hatch out, and the larve undergo transformation 
early in the season and begin to do mischief before the 
migrant birds return. 
“Tf it were not for sleet storms, that cover the tree 
with a coating of ice for days at a time, these hardy, 
sociable little birds would be sure of a good living in 
a neighbourhood like this, with many orchards and 
strips of woodland. But when ice puts a lock on the 
pantry doors, what can the poor birds do? 
“Owing to their frail structure and warm blood, they 
require more constant fuel to keep the life-fire alive than 
the four-footed animals, so that when hunger and cold 
travel hand in hand, they have to make a brave fight 
for life. For generations this freezing up has happened 
to them, and so, by experience, they have learned when 
food is plenty to try and save it up. 
“The Nuthatch, that Sarah has just seen stowing 
something away under the shingles, is living very well 
at present. In spite of hard frost, wild food is plenti- 
ful; then, too, the lunch-counter is amply supplied with 
suet. The birds do not really need help as yet, but we 
