92 Animal Life 
dor-hawk. Other names—eve-churr and nightjar—have obviously been suggested by his 
characteristic note, the long continued vibrating “chur-r-r” set up after the sun has 
gone down. 
What is the purpose of this strange vocal effort is not known. It cannot be 
classed with the song of the nightingale and other birds that sing for the delectation 
of the female whilst she is engaged in the tedious busimess of incubation, for it is 
continued long after the eggs have been hatched, in fact right up to the time of the 
bird’s departure from this country. 
A heath well-clad with fern, furze, and the other characteristic vegetation of 
such places, and surrounded by woods, is the favourite haunt of this bird. ‘There in 
the twilight they may be seen, sometimes to the number of a dozen or a score, flitting 
and sweeping in huge circles through the air, catching the moths and beetles that 
are then enjoying to the full their possession of wings. The nightjar has been likened 
to a great moth, and the resemblance is by no means slight. It is one of the finest 
examples of protective colouring afforded by the larger wild creatures of this country. 
It is not a simple task to 
describe this colouring in a few 
words, for there is no definite 
pattern; spots and streaks and 
splashes of browns, yellows and 
blacks appear as though laid 
on haphazard, and yet they 
produce a very harmonious 
effect that fits mm with any of 
their usual surroundings. Like 
many other examples of pro- 
tective colouration, its beauty 
cannot be fully appreciated in 
a museum specimen divorced 
from its ordinary environment. 
Set it down on the moorland 
among the heather, and at 
once it becomes practically in- 
visible. The stones, the lichens, 
the dead twigs, the sprays of heath and the spines of furze are all figured on 
its plumage, and these counterfeit presentments unite with the real things around 
them so completely that you cannot readily see the points of Junction between the 
actual and the apparent. 
On page 95 is a photograph of a young but full-fledged bird among heather, with 
which it harmonises so well that I have had to subdue these surroundings in order that 
the representation of the bird may be fairly distinct. Strange to say, assimilative colouring 
is equally effective for protective purposes when the bird squats toad-hke on the limb 
of a tree. The nightjar perches along, not across the branch as most birds perch, and 
the darker lines and spots on its plumage then harmonise with the cracks and 
irregularities of the bark and the lichens upon it. The wings are drooped to the 
bixd’s sides, and so connect it with the tree that it might easily be mistaken for a mere 
natural excrescence such as are commonly found on trees. : 
The habits of the bird have given natural selection full play throughout its life. 
It lays its two eggs upon the ground, selecting some bare spot among heather or fern, 
at the foot of a fir tree or under a furze bush. There is not the slightest pretence 
at making a nest, not even to the extent of scratching a hollow, though sometimes 
NIGHTJARS JUST HATCHED. 
