The daily morning journal and courier. [volume] (New Haven, Conn.) 1894-1907, 1907-01-05
MIGRATION OBJ BIRDS.
Their Sense of Locality Well Devel-
oped..


The migration Of birds is a subject
which is full of intesesting and difficult
problems, and not the least interesting
nor the least difficult of comprehension
is the question how they find their way,
About the admirable accuracy of their
movements there is no question what
ever. The willow warbler viii come
back year after year to occupy the
same position, in the same tangle of
| grass and underground, as the site for
its nest. Others are no less accurate
and punctual; but the eXactness of this
/ little bird is the more remarkable be-
| cause of its apparently feeble powers of
| flight, which seem to leave 1t quite I'M
| provided with the locomotive means re-
quired to bring it 50 unerringly in its
goal, While the questions which mi
grafton presents are difficult enough of
| understanding, there is one which tran
sends all the rest in its obscurity. 1t
| is the question which Is suggested by
| the fact, apparently quite well anthem
ticated, that in the case of many spe-
|
year that lead the migration flight. OF
coursa this is the kind of fact which is
very difficult of proof 1t is open to the
objector to say: How do you know
that there are not a few old birds, per-
haps the barren birds of the year, TAX
ing part in the earliest migration
flights of the species, and so giving
lead to the youngsters along a line
Which has become familiar to them
through previous travel? 1t is diff
cult to answer this objsctor satisfacto-
rily, because he at once puts his OPP
ponent into the position of one who has
to prove a negative, and we all know
what an uncomfortable position that is.
The pros and cons of the whole argu-
ment are far too long and intricate to
enter into here. All we we can do is to
ask the reader to accept the verdict of
such observers as. Gatke and many
more that the birds of the year in many
cases do lead the migration fight, that
some instinct acts as thsir compass and
that they 40 not avail themselves Of
the guidance of any old or barren birds.
No doubt to ask credence for such a
statement is to ask a good deal This
explanation sometimes offered, that
these birds are led by inherited instinct
. along the migration lines followed by
their forefathers, in some cases pursu-
ing the course of d long-since sub
merged river or other visible guiding
line is an explanation almost as hard
OF acceptance as the original mystery
8 which 1t is invoked to explain Nor
! does the mystery become any less mys-
ferrous, though it becomes more posi-
Bile of credence, even II not of compre-
hension, when we consider 1t alongside
i Of other examples Of al like kind with
e which natural history can furnish us.
t For 1t does not stand alone by any
:, means. If It did, we might indeed ask
Y credence for 1t In vain The instinct
!. as it appears to be, which leads ami.
Y mails to direct their course to a certain
: spot without, so far as we are able tc
ascertain any previous hint or indica-
h ton of guidance, demonstrates itself in
/ several remarkable ways besdss that
t Of the migration flight, but In none
4 perhaps more remarkably than in the
3 case of the guanano, a Species of llama
a of South America, which resorts In i'm
: mense numbers to a certain place. tt
i die. In fact, 1t seems. from the &C.
Z counts given by Darwin and by Mr.. w
); H. Hudson, that all the guanacos ni
i the southern part of Patagonia mus
: resort when the hour Of death ap
. proaches, to certain spot in certain
! riverbed which has become a perfec
: mausoleum Of their bones Mr.. Hudson
has hazafded a very ingenious hypoth
esos to account for this assemblage II
= the common mortuaryt He notes, pri
:, marly, that 1t is only the guanaco o
\ the southern extremity, of the Soutt
=" American continent that has this hab
: 1t; which Is as much as to say that /
2 is habit restricted to descendants O
= forefathers who lived at one time in al
Il extremely rigorous, serni-Antarctic eli
y mate. Mr.. Hudson conjectures tina
e among these forefathers the instinc
/ grew up, when the stress Of hunger AM
y cold was very dire and they felt IT.
Il chill setting upon them, of resorting t.
n this sheltered place in the river bsd
a where they might find warmth in thei
e own closely collected numbers, and pos
y sibly food, which would enable them t,
It outlive the days Of extreme rlgor. by
: a continual survival of those which be
: took themselves to this place of refuge
: the race instinct would be formed O
resorting thither when they felt the
r tides Of life runninglow This feeling
4 | Mr.. Hudson argues, their descendants
Y are likely to experience now at the ap,
i proach of the hour of DEATH and in
: obedience to it to flock to the same re-
= sort But now 1t is no longer just q
e passing spell of extreme cold which
they can hope to survive that leads
/ them thither. The dsath call has come
9 and they must lay their bones in the
: common mortuary. 1t is not "in order
! TO die" as we so frequently say with a
very common error In considering the
, | ways of animals, that the guanaco
seeks this place; 1t would be nearer the
truth If we were to say 1t was "in or
! der to live" But the most true ae-
+ doubtcount of all, no doubt Gf the
hypothesis is accepted) is that it is
| with no conscious purpose at all, but
in mere obedience TO the inherited in
stinct, that the guanaeo resorts to this
; refuge; and still the hypothesis, for all
! its ingenuity, leaves unanwer6d the
question (save as 1t Is answered by the
so-caled explanation" of the migration
, flight how the guaco is guided to this
shslter of its forefathers from the
! | Antarctic cold. Yet another instance