Northern Wisconsin advertiser. [volume] (Wabeno, Wis.) 1898-1925, 1901-01-03
a pARwlNiAN coNunpRum
Why 10 the Bill Of the New Zealand
Plover Bent to the Riuht7

Explanatory data, coming suddenly
upon the scene, when
Round and round the vinegar jug
The monkey chased the weasel"
might easily fail into a dispute as to
which one was chasing the other;
which stood in the relation OF cause,
and which in that of effect, of the i'm
pulse to run. One can imagine the ar
ray OF arguments that would be mar
shalled on each side to prove one ami
NAL or the other the chaser and his COM
panion the chasee. Such a dilemma
now and then confronts the reasoning
evolutionist as to the history of some
form or phase of animal structure or
habits. For example:
The wry-billed ploved of New lea
land is neatly dressed, hazel-eyed lit
tie shore bird, which runs silently
ahead of you as you walk along the
beach, moving rapidly at the edge Of
the waves in search of food, and ninb-
ly, but not nervously keeping out of
your way; yet they can run so fast on
ljust occasion that, as one writer puts
1t, their little black legs seem TO re-
volve like spokes of wheel. Thus
Tar, as sportsmen all know. there is
nothing very remarkable about this
plover; but closer examination
proves that its bill is one of the curl
osi:ies Uf ornithology, for the outer
third OF this brad-awl-like instrument
is decidedly bent toward the right
Other birds have a midway bend down
ward. as is seen in tlc ugly mug" Of
the hamingo, or decided tilt upward
toward the tip, as in the case of the
curlews and some humming birds, but
in no other bird is the beak bent side
ways. as IL accidentally deformed.
When this plover was first brought
to Europe, in 1929 it was, indeed, re-
garded as deformity, and wise men
declared 1t could not be otherwise, but
1t was presently proved (for the pretty
little creature is common enough at the
antipodes) that it was normal and was
characteristic even of chicks in the
egg. So the museum men had to come
down and apologize to the field OBJ
servers. as they have been doing ever
since Aristotle began to upset their
cant be- by his 1t is"
Now such a feature as this cannot
be regarded as freak or purposeiess,
and the habits Of this little mouse
colored sand-runner began to be OBJ
served very closely to see what use was
made OF these bent tyeezers. 1t was
noticed that he constantly trotted close
beneath the powders that so common
ly strew the seashore in New Zealand
and inserted his bill beneath them to
obtain his food. which is such fiuvia-
tile insects and minute crustaceans as
are in the habit of lurking out of sight
i'm the crevices between such rocks and
the wet sand. There they are SAFE
ordinarily, from aight-beaked
bird. but this bent bill can penetrate
far enough to seize them, and the in
dustrious plover, provided with this
special tool, picks out many a living
morsel secure from all other sorts Of
lshore birds
This success requires, of course, that
the bird shall always go around the
bowlder in the same way-namely,
keeping the rock on its right. for the
bill is bent to that side. Now this con-
dition is accompanied by very curl
Gus coincidence. for it appears that the
rather conspicuous black band across
the breast is not of equal width on the
Of less decided color on the left. or ex-
posed side, than on the right side,
which is next the stone and hidden
from view.
Darwinians Immediately told us that
this was an acquired popularity, ac-
companying the asymmetry of the bill,
which tended TO protect its owner IRON
hawks, or other nenies while search
ing for its food by making it less no
,ticeable, since otherwise its dun plum-
age was practically invisible among
the stones of the strand. This seemed
nice and easy until somebody asked an
Explanation. Then the naturalistS
found themselves confronted by much
the same difficulty as the philosophers
who could not be certain as to whether
the monkey was chasing the weasel Or
the weasel pursuing the monkey.
Shall we say that the bend in this
plovers bill is an acquired peculiarly
due 20 its evident advantage as now
used, and that it has resulted in the
birds habit OF always running in one
way around each stone, and hence has
ioaen followed by the decrease Of daa-
lgaTous color on the more exposed side?
o, vice versa, shall we conclude that
because. in primitive times, the bird
got into the habit OF always feeding
about n 5owlder from left to right. the
beaks Of its descendants gradually ae-
fVulred a bias in that direction. amount
lax now 70 a marked ana permanent
bend?
rs very pretty Darwinian quarrel
nc I 80 nj.