BIRD SYMPATHY
To-day--which is my third here upon the island--I was actually
assaulted by the terns. I saw a young one, now well advanced, that
flew for a little and then went down on the grass. Walking towards
it, a bird--presumably one of the parents--descended upon me twice in
succession, and, with that angry and piercing cry that I have spoken or
ought to have spoken of--it sounds very like a shrill "bah!"--delivered a
fierce peck at my head, so that I felt it each time, quite unpleasantly,
through the thin cloth of my cap. The difference is to be noted in
this form of attack, to that employed by gulls and skuas, the former
in battles _inter se_ only, and the latter as against man in defence
of their eggs or young. Both of them, when they thus "swoop to their
revenge," use the feet only, and the superiority of the tern's method is
so great that it makes this small bird almost as redoubtable--if this
exaggerated word may be pardoned--as even the largest of the others. The
Great Skua, especially, were it to use its powerful beak, would be really
formidable, even to a man. In fighting with its fellows, it no doubt
does so, and gulls, under these circumstances, make the greatest use of
theirs. This, however, is when they struggle together on the ground;
but when one fights on the ground and the other in the air, the latter
uses its feet only, with effects that are irritating rather than to be
feared. Now why is this, and what causes the difference in this respect
as between gull and tern? From my own observation I think I can explain
it. So long as two contending gulls fight with any equality, they do so
upon the ground, but when one of them can no longer hold his own there,
he rises into the air and, sweeping backwards and forwards over the
other, who stays where he was, annoys him in this particular way. The
bird, therefore, by whom these tactics are resorted to has already got
the worst of it, and the last thing he wishes is again to close with a
rival who has defeated him. This, however, is exactly what would happen
were he to use his hooked beak in the manner proper to it, for it is
adapted for seizing and tearing, and to these uses it has hitherto been
put. To peck or stab with it would be like making a thrust with a sickle,
and though possibly as against a weaker antagonist it might be made
effectual in some other than the normal way, yet here there is always the
fear of detention, to check any experiment of the sort. Let the hooked
tip but pierce the skin to any extent, and the swoop would be checked
sufficiently to allow of the flying bird's being seized. The feet,
therefore, though without efficient claws and quite unadapted to anything
except swimming, are employed by preference, and in the manner in which
they are used we see the same principle at work, for instead of making
any attempt at grasping or scratching, the flying gull, as it sweeps by,
just gives a flick with the back of them, which the other revenges or
parries with a blow of the wing.
The tern, however, having a straight and sharply pointed bill, adapted
for pecking, and nothing else, can use it in this manner when flying
also, though in other respects it delivers its attack in exactly the same
manner as the gull does, allowing for the difference in bulk and aerial
grace and mastery, between the two birds. Here, as it appears to me, we
see structure affecting habit. As a rule, I think, it is rather the other
way, for it is wonderful to how many uses, other than the primary one
for the performance of which it has been specially adapted, almost any
part of an animal's anatomy may be put. And indeed, if we look at it in
another way, this truth is as strikingly illustrated by what we have just
been considering as by almost anything, for the webbed foot of a gull or
any swimming bird is extremely unadapted for fighting, and yet we here
see it thus employed. But it is owing to the structure of the beak, in
my opinion, that this has come about. That is the bird's real weapon,
which I am convinced it would always use if it could or if it dared. Not
even in their rough-and-tumbles, where they close and roll over and over
together, have I seen gulls fight with their feet, upon the ground.
I had not gone far, after this episode with the terns, when I was pecked
at, twice again, by another one, under similar circumstances. Each
time, I believe, the sharp point of the beak went through the slight
stuff of my cap, or I should hardly have felt it so sharply. It is not
only the skuas, then, that attack you in defence of their young. These
terns, though so much smaller, do so too, and, as appears by the story,
they have more than one weapon in their armoury. But a more interesting
experience was in store for me, which brought still more forcibly to my
mind that incident with the wounded tern to which I have before alluded.
Walking on, I noticed a bird which, though a young one, looked almost
in its full plumage, and which kept flying for a little, and then going
down again at some distance in front of me. Every time it alighted, a
cloud of terns hovered excitedly over it, and first one, and then another
of them kept swooping down, so as just or almost to touch it, until at
last it flew up again, so that I could never approach it more nearly. It
certainly seemed to me as though the grown community were trying to get
this young one to fly, so as to be out of danger, and this they always
succeeded in doing. I do not think they really prevented me from catching
the bird, for, no doubt, it would have flown of itself before very long;
but what interest and sympathy shown! Moreover, had I been pursuing it
with a gun it might have made all the difference.
[Illustration: BIRD SYMPATHY]
So, too, it must be considered how lethargic these young terns are
before they can fly, and how easily they then let themselves be caught,
though able to run quickly. When noticed, or approached closely, they
crouch, but though this is probably due to an inherited instinct of
self-preservation, they do not appear to have much fear of one. Therefore
it seems likely that in their early flying days they might still be
inclined to act in this way, and if so, any encouragement to fly which
they received from their elders would be of assistance to them. It is
noteworthy that the younger birds which I caught were not thus encouraged
to run. The public attention, in this case, seemed concentrated on myself.
Terns vary much in the degree of resistance, or rather of evasion, which
they offer to the attacks of the skuas--always I am speaking of the
smaller of the two species. I have often seen them get off scot-free,
without losing their fish, and, as before said, this has always seemed
to me to be because of their persistency in holding out, and not at all
on account of their superior speed. I have advanced a theory as to why
the skuas should not actually attack the terns on these occasions, as
they do not seem to me to do, and if there is any truth in it, we here
see a road along which a certain number of the latter might become free
of the tyranny under which they now suffer. It is doubtful, however,
whether these more obstinate birds would gain, in this way, a sufficient
advantage over the others to allow of natural selection coming into play.
They could carry, no doubt, more fish to their young, but here, at least,
the skuas seem hardly in sufficient numbers to make the difference a
working one. With many birds, however, a similarly acquired change of
habit would mean the difference between life and death. I remember once
passing unusually close to a cock pheasant, which remained crouching
all the while, though nineteen out of twenty birds would, I feel sure,
have gone up. It struck me, then, that as all such pheasants as acted
in this way would have a greater chance of not being shot than the
others that rose more easily, whilst these latter were constantly being
killed off, therefore, in course of time, the habit of crouching close
ought to become more and more developed, and pheasants, in consequence,
more and more difficult to shoot. Some time afterwards I met with some
independent evidence that this was the case, for a gentleman who shot
much in Norfolk, remarked, without any previous conversation on the
subject, that the pheasants there had taken to refusing to rise, and
that this unsportsmanlike conduct on their part was giving great trouble
and causing general dissatisfaction. That was his statement. He spoke
of it as something that had lately become more noticeable, but only, as
far as his knowledge went, in Norfolk, which, I believe, is an extremely
murderous county.
Beyond this I have no knowledge on the subject, but I feel sure that
a gradual process of change and differentiation is every day going on
amongst numbers of our British birds. I believe that I have myself, here
and there, seen some traces of it, and my idea is that greater pains
ought to be taken to collect evidence in this and similar directions.
Along all those lines where fluctuation has been observed, or where
modification might, in course of time, be expected, the present truth
should be most carefully made out, and having been accurately recorded
and published, observation, after a certain length of time, should again
be focussed on the same points, and this being renewed every ten, twenty,
fifty, or a hundred years, the results could be compared. For instance,
our green woodpecker feeds now largely upon ants in their nests, whilst
it both fights and copulates upon the ground. How interesting would
it be if we had a continuous record of observations of this bird's
habits, dating, say, from William the Conqueror or the days of the
Saxon Heptarchy, and if we found that no mention was made of these
peculiarities, by the field naturalists of those times, but that they
first began to be doubtfully recorded in the reign of Henry the Fifth, or
Richard the Third. No doubt a connected chain of evidence of this kind
will gradually grow up, owing to the accumulation of works of natural
history, but it would, I think, be a great deal more satisfactory if the
object were kept steadily in view, and I am quite sure that observations
made in this spirit would produce much more interesting matter than that
which is to be found in the ordinary bird or beast book. For the great
idea would then be to compare the present with the past habits of any
creature, in order to see whether, or in what degree, they have changed,
and this could only be done by continual re-observation, which would
assuredly lead to novelty of some sort, instead of mere repetition,
which is what we have now; and not only so, but the thing that is so
constantly repeated seems often to be founded either on nothing, or
nothing that one can get at. Take, for instance--but no, that would lead
to twenty more pages at the least, and I want them for something better.