THE CUCKOO
With the single
exception of the nightingale, bird of lovers, no other has been more
written of in prose or verse than the so-called "harbinger of
spring." This is a foolish name for a visitor that does not
reach our shores before, at any rate, the middle of April. Even
Whitaker allows us to recognise the coming of spring nearly a
month earlier; and for myself, impatient if only for the illusion of
Nature's awakening, I date my spring from the ending of the shortest
day. Once the days begin to lengthen, it is time to glance at the
elms for the return of the rooks and to get out one's fishing-tackle
again. Yet the cuckoo comes rarely before the third week of April,
save in the fervent imagination of premature heralds, who, giving
rein to a fancy winged by desire, or honestly deceived by some
village cuckoo clock heard on their country rambles, solemnly write
to the papers announcing the inevitable March cuckoo. They know
better in the Channel Islands, for in the second week of April, and
not before, there are cuckoos in every bush—hundreds of exhausted
travellers pausing for strength to complete the rest of their journey
to Britain. Not on the return migration in August do the wanderers
assemble in the islands, since, having but lately set out, they are
not yet weary enough to need the rest. The only district of England
in which I have heard of similar gatherings of cuckoos is East
Anglia, where, about the time of their arrival, they regularly
collect in the bushes and indulge in preliminary gambols before
flying north and west.
Cuckoos, then,
reach these islands about the third week of April, and they leave us
again at the end of the summer, the old birds flying south in July,
the younger generation following three or four weeks later. Goodness
knows by what extraordinary instinct these young ones know the way.
But the young cuckoo is a marvel altogether in the manner of its
education, since, when one comes to think of it, it has no upbringing
by its own parents and cannot even learn how to cry "Cuckoo!"
by example or instruction. Its foster-parents speak another language,
and its own folk have ceased from singing by the time it is out of
the nest. A good deal has been written about the way in which the
note varies, chiefly in the direction of greater harshness and a more
staccato and less sustained note, towards the end of the cuckoo's
stay. According to the rustic rhyme, it changes its tune in June,
which is probably poetic licence rather than the fruits of actual
observation. It is, however, commonly agreed that the cuckoo is less
often heard as the time of its departure draws near, and the easiest
explanation of its silence, once the breeding season is ended, is
that the note, being the love-call of a polygamous bird, is no longer
needed.
In Australia the
female cuckoo is handsomely barred with white, whereas the male is
uniformly black; but with our bird it is exceedingly difficult to
distinguish one sex from the other on the wing, and, were it not for
occasional evidence of females having been shot when actually
calling, we might still believe that it is the male only that makes
this sound. The note is joyous only in the poet's fancy, just as he
has also read sadness into the "sobbing" of the
nightingale. There is, indeed, when we consider its life, something
fantastic in the hypothesis that the cuckoo can know no trouble in
life, merely because it escapes the rigours of our winter. Eternal
summer must be a delight, but the cuckoo has to work hard for the
privilege, and it must at times be harried to the verge of
desperation by the small birds that continually mob it in broad
daylight. This behaviour on the part of its pertinacious little
neighbours has been the occasion of much futile speculation; but the
one certain result of such persecution is to make the cuckoo, along
with its fellow-sufferer, the owls, preferably active in the sweet
peace of the gloaming, when its puny tyrants are gone to roost. Much
heated argument has raged round the real or supposed sentiment that
inspires such demonstrations on the part of linnets, sparrows,
chaffinches, and other determined hunters of the cuckoo. It seems
impossible, when we observe the larger bird's unmistakable desire to
win free of them, to attribute friendly feelings to its pursuers. Yet
some writers have held the curious belief that, with lingering
memories of the days when, a year ago, they devoted themselves to the
ugly foster-child, the little birds still regard the stranger with
affection. If so, then they have an eccentric way of showing it, and
the cuckoo, driven by the chattering little termagants from pillar to
post, may well pray to be saved from its friends. On the other hand,
even though convinced of their hostility, it is not easy to believe,
as some folks tell us, that they mistake the cuckoo for a hawk. Even
the human eye, though slower to take note of such differences, can
distinguish between the two, and the cuckoo's note would still
further undeceive them. The most satisfactory explanation of all
perhaps is that the nest memories do in truth survive, not, however,
investing the cuckoo with a halo of romance, but rather branding it
as an object of suspicion, an interloper, to be driven out of the
neighbourhood at all costs ere it has time to billet its offspring on
the hard-working residents. All of which is, needless to say, the
merest guesswork, since any attempt to interpret the simplest actions
of birds is likely to lead us into erroneous conclusions. Yet, of the
two, it certainly seems more reasonable to regard the smaller birds
as resenting the parasitic habit in the cuckoo than to admit that
they can actually welcome the murder of their own offspring to make
room in the nest for the ugly changeling foisted on them by this
fly-by-night.
On the lucus
a non lucendo principle, the cuckoo is chiefly interesting as a
parent. The bare fact is that our British kind builds no nest of its
own, but puts its eggs out to hatch, choosing for the purpose the
nests of numerous small birds which it knows to be suitable. Further
investigation of the habits of this not very secretive bird, shows
that she first lays her egg on the ground and then carries it in her
bill to a neighbouring nest. Whether she first chooses the nest and
then lays the egg destined to be hatched in it, or whether she lays
each egg when so moved and then hunts about for a home for it, has
never been ascertained. The former method seems the more practical of
the two. On the other hand, little nests of the right sort are so
plentiful in May that, with her mother-instinct to guide her, she
could always find one at a few moments' notice. Some people, who are
never so happy as when making the wonders of Nature seem still more
wonderful than they really are, have declared that the cuckoo lays
eggs to match those among which she deposits them, or that, at any
rate, she chooses the nests of birds whose eggs approximately
resemble her own. I should have liked to believe this, but am
unfortunately debarred by the memory of about forty cuckoo's eggs
that I took, seven-and-twenty summers ago, in the woods round
Dartford Heath. The majority of these were found in hedgesparrows'
nests, and the absolute dissimilarity between the great spotted egg
of the cuckoo and the little blue egg of its so-called dupe would
have impressed even a colour-blind animal. Occasionally, I believe, a
blue cuckoo's egg has been found, but such a freak could hardly be
the result of design. As a matter of fact, there is no need for any
such elaborate deception. Up to the moment of hatching, the little
foster-parents have in all probability no suspicion of the trick that
has been played on them. Birds do not take deliberate notice of the
size or colour of their own eggs. Kearton somewhere relates how he
once induced a blackbird to sit on the eggs of a thrush, and a
lapwing on those of a redshank. So, too, farmyard hens will hatch the
eggs of ducks or game birds and wild birds can even be persuaded to
sit on eggs made of painted wood. Why then, since they are so
careless of appearances, should the cuckoo go to all manner of
trouble to match the eggs of hedgesparrow, robin or warbler? The bird
would not notice the difference, and, even if she did, she would
probably sit quite as close, if only for the sake of the other eggs
of her own laying. Once the ugly nestling is hatched, there comes
swift awakening. Yet there is no thought of reprisal or desertion. It
looks rather as if the little foster-parents are hypnotised by the
uncouth guest, for they see their own young ones elbowed out of the
home and continue, with unflagging devotion, to minister to the
insatiable appetite of the greedy little murderer. A bird so imbued
as the parasitic cuckoo with the Wanderlust would make a very
careless parent, and we must therefore perhaps revise our
unflattering estimate of its attitude and admit that it does the best
it can by its offspring in putting them out to nurse. This habit,
unique among British birds, is practised by many others elsewhere,
and in particular by the American troupials, or cattle-starlings. One
of these indeed goes even farther, since it entrusts its eggs to the
care of a nest-building cousin. There are also American cuckoos that
build their own nest and incubate their own eggs.
On the whole,
our cuckoo is a friend to the farmer, for it destroys vast quantities
of hairy caterpillars that no other bird, resident or migratory,
would touch. On the other hand, no doubt, the numbers of other small
useful birds must suffer, not alone because the cuckoo sucks their
eggs, but also because, as has been shown, the rearing of every young
cuckoo means the destruction of the legitimate occupants of the nest.
So far however as the farmer is concerned, this is probably balanced
by the reflection that a single young cuckoo is so rapacious as to
need all the insect food available.
The cuckoo, like
the woodcock, is supposed to have its forerunner. Just as the small
horned owl, which reaches our shores a little in advance of the
latter, is popularly known as the "woodcock owl," so also
the wryneck, which comes to us about the same time as the first of
the cuckoos, goes by the name of "cuckoo-leader." It is
never a very conspicuous bird, and appears to be rarer nowadays than
formerly. Schoolboys know it best from its habit of hissing like a
snake and giving them a rare fright when they cautiously insert a
predatory hand in some hollow tree in search of a possible nest. It
is in such situations that, along with titmice and some other birds,
the wryneck rears its young; and it doubtless owes many an escape to
this habit of hissing, accompanied by a vigorous twisting of its neck
and the infliction of a sufficient peck, easily mistaken in a moment
of panic for the bite of an angry adder. Thus does Nature protect her
weaklings.
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