DARWINIAN EIDER-DUCKS
I have seen a fair number of eider-ducks within the last few days. All
the grown ones are females--not a male to be seen now--and the greater
number of them are unaccompanied by ducklings. Of those that are, most
have but one, and three is the maximum number that I have seen swimming
together with their mother. Yet two years ago, in early June, the males
here were courting the females, and when I left, about the middle of the
month, but very few eggs, I believe, had been laid. This year, I learn,
the birds have been very late in breeding, there having been some very
"rough weather," as it is euphoniously called, in the spring--that is to
say, the spring has been like a bad winter, and now the summer, though
it has no very close resemblance to any of the four seasons as I have
seen them elsewhere, yet comes nearest to a phenomenally bad November. I
wonder, therefore, that so many of these mother eiders are without their
young ones, for they should all have hatched out a brood of them not so
very long ago. Why, too, should so many be swimming with one duckling
only? Were these single ones of any size, one could understand the others
of the brood having escaped from tutelage, but, like all I have seen,
they are but little fluffy things. It looks as though their fellow
nestlings had come to grief in some way, and if so it is probable that
many entire broods have also. Yet perhaps they have merely drifted away
into the wide, watery world, where they may be able enough to shift for
themselves thus early. To judge by these, however, they would not have
left the mother duck voluntarily--they are dutiful, dependent little
things.
Where the coast is iron-bound, in delightful little bays and
inlets--those sea-pools lovely to look down upon--one may watch the
eiders feeding on the rocks, and try, through the glasses, to make out
exactly what they are getting. In this way I am amusing myself this
morning, having just run round a projecting point, towards which a
family of three were advancing, and concealed myself behind a projecting
ridge. Over this I can just peep at some black rocks, up which, whilst
their mother waits, the little ducklings now begin to crawl. So steep
is the slope that sometimes they slip and roll a little way down it,
but they always recover themselves and run up it again, none the worse.
In the intervals between such little mishaps they seem to be picking
minute shell-fish off the rock; but what shell-fish are they? for the
small white ones, with which large areas of the rock are covered, are
as hard as stone, and might defy anything short of a hammer and chisel
to dislodge them. It is not on these assuredly that these soft little
things are feeding, and now I see that where they are most active the
rock is black. There are broad, black bands and streaks upon it, but
what these consist of, or whether they are anything more than seaweed
I cannot quite make out; and here, where I lie, being above the sea's
influence, there is nothing similar to instruct me. Rocks now I find--as
I have often before--are inferior to foliage for concealing oneself, that
is, if one wishes to see as well as to be unseen. One's head, projecting
over their hard, sharp, uncompromising lines, catches the eye of a wary
bird, and recesses made by their angles are not often to be found where
one wants them. Twice has the mother duck been slightly suspicious, and
now, to my chagrin--though it really should not be, for what can be more
entertaining?--she goes to the length of calling her ducklings off the
rock. This she does by uttering a deep "quorl"--a curious sound, not a
quack, but something like one--on which they come scurrying down to join
her, putting off to sea with the greatest precipitation, like two little
boats that have only just themselves to launch--no waiting for people
to get into them. I have heard this note before, and always it has been
uttered as a danger-signal to the chicks. There is another one that is
used on ordinary occasions, and this much more resembles a true "quack."
In spite of these various alarms, however, the young eiders are soon on
the rock again, and after a while the mother walks up it, too, and begins
picking and pulling with her bill over these same black surfaces. I still
cannot quite make out, though now I surmise, what it is that gives
this black, or rather indigo, tinting to the rock, and in trying to get
nearer, the mother duck is again alarmed, and with another deep "quorl"
or two, runs quickly down the slant, and slides into the water, close
followed by her two little children. This time she swims away with them
and returns no more, leaving me as disappointed as though I had thirsted
for her blood.
Going down now to the rocks, where they have just been, I find that the
black appearance of which I have spoken is caused by immense numbers
of quite small mussels which grow thickly wedged together. It is on
these that all three have been feeding, and I have no doubt that they
form one of the staples of the eider-duck's food just now. Earlier in
the year it seemed to be all diving, and when they brought anything up
it did not look like a mussel. All about the rocks there are certain
little collections of broken mussel-shells--often of a very pretty violet
tint--coagulated more or less firmly together, and these must evidently
have been ejected, as indigestible, by birds that had swallowed them; but
whether by gulls only, or by both gulls and eider-ducks, I cannot tell.
Gulls, I know, disgorge these queer kinds of pellets as well as others
still more peculiar, since they occur over the interior of the island in
numbers too great for any other bird to have produced them.
The eider-ducks, therefore, feed on the beds of mussels that the sea
exposes at low tide, but they also, to go by appearances, devour the
actual seaweed, irrespective of anything that may be growing upon
it. Having seen them do both, I see no reason why I should reject the
evidence of my eyesight in the one case more than in the other. What
interests me is that I have several times during this week seen the
same duck, with her young ones, feeding along this one flat part of the
coast-line, where it forms a beach, whereas all the others that I have
seen have kept in the neighbourhood of the rocks. Even about the shores
of this small island it seems as though a process of differentiation were
going on, and that whilst the great majority of the eider-ducks affect a
diet of shell-fish, and, therefore, haunt the broken, rocky parts where
it is to be best obtained, some few prefer the seaweed growing on the
smooth, shallow bottoms, which they therefore do not leave, or, at least,
more frequently resort to.
A difference of food like this, involving a residence in different
localities, must lead to change in other habits, to which structure
would, in time, respond, so that, at last, upon Darwinian principles,
two different birds would be produced. Thus anywhere and everywhere one
may see with one's own eyes--or think that one sees, which is just as
instructive--the early unregarded stages of some important evolutionary
process.
It is a good thing, I think, thus to exercise one's imagination, and
by observing this or that more or less slight deviation from the main
stream of an animal's habits, to try and picture its remote future
descendants. Too little, I think, has been done in this way. The
imaginative element is one without which all things starve. In natural
history it is particularly wanted, and would have particularly good
effects. Most naturalists think only of what is the rule in any animal's
habits--exceptions they do not care about--yet, looked at in a certain
way, they are still more interesting. Moreover, there is a great tendency
to see an animal do just what it is supposed to do, and this tendency
does not conduce to keen and interested observation. But the future
modification of any species must depend largely upon deviations, on the
part of individuals belonging to it, from its more ordinary line of
conduct, so that any man who should wish rationally to speculate on this
future must become, perforce, a patient noticer of such deviations, and,
therefore, a great observer of the animal in question.
To support a theory is a great motive towards the collection of facts,
yet a number of small-minded people are always deprecating what they
call "mere theory" in field natural history, and crying out for facts
only. Theory, however, is a soil in which facts grow, and there is a
greater crop from a false one than from none at all. The history of
astrology and alchemy are instances of this--if, indeed, the latter, in
its fundamental belief, does not turn out to have been true after all.
When have men been much interested in facts--apart from mere gaping
wonder or amusement--except in connection with some idea in their mind,
which, by giving, or seeming to give, them significance, as it were
irradiated them? The "matter-of-fact man," as that lowest type of one is
called, is interested in comparatively few facts even, and such fancy and
imagination as he does possess plays around those few.
To return to the eider-ducks, I cannot, of course, be quite certain that
it is always the same family party that I see along the beach by the
fringe of seaweed, but I have little doubt that it is; for, in the first
place, it always consists of the mother and three ducklings, and in the
next, there is never another bird or party of birds there at the same
time with them. The double coincidence is, I think, decisive, for most
of the eiders that have ducklings at all, have either one only or two,
whilst the greater number are without any. But then, to be sure, I have
only been here a week, nor have I given the matter any very _special_
attention. It is not quite _constaté_, only I like to think things, and
then think as though they were as I think.