The Coolidge examiner., 1938-01-27

/ n n AIN people DeHeVe
! MI that all butterflies
live but a few days,
and that they keep quite
close to the locality where
they hatch. This is true of
most species, but there are
others which live for weeks,
sometimes for months, and
instead of futtering around
they may set off in definite
direction and fly. some hun
dredS, or even thousands Of
miles from their birthplace
before settling down to lay
their eggs.
This habit Of changing location,
or migration, has been known to
occur in birds and locusts since
ancient times, and has been sus-
| pected for about a century in the
butterflies and moths. The cotton
worm moth of the southern United
States was one Of the first in North
| America TO come under suspicion.
/ Today the habit is also known
among some dragonhies and
beetles, particularly the ladybirds,
and more rarely in other groups
/ Of insects.
The butterflies may migrate
/ singly or in large numbers. Flights
estimated to contain more than a
thousand million individuals have
| been recorded. The sight Of one of
these butterfly movements, the in
sects passing for hours and even
days, steadily pressing on in one
/ direction, is an event in the life Of
any naturalist.
BY piecing together scattered and
complete information, much as
one might try to fit together a jig
saw puzzle of which most Of the
pieces have been lost, we begin in
a few cases to have some idea of
the extent of the movements; of
where the butterflies start, what
route they take, and where they
come TO rest.
Monarch Has JOurneyed Far.
By far the best known Of the mi
grants is the Monarch or Milkweed
butterfly. This magnificent insect
| has its headquarters in North Amer
ica and has spread, chiefly in his
toric times. to the Cape Verde is
lands and Madeira in the Atlantic,
and to most Of the islands of the
Pacific. 1t is said TO have reached
New Zealand about 1910 and ap-
peared in Australia about 1870. In
both Of those countries it is now
established.
In the past sixty years nearly
| hundred individuals have been seen
in Great Britain and much small
er number in France and Portugal.
Nearly all these were observed in
the autumn. The food plant. milk
weed, does not exist wild in Eu-
rope, so the butterfly has never
become established there. It is not
yet known for certain whether the
European specimens have flown
across the Atlantic, assisted by the
prevailing westerly winds. or have
been carried across in ships.
In North America this butterfly is
found during the summer through
out the United States and Canada
as far north as Hudson bay and. in
the West, occasionally as far as
Alaska. In the early autumn, the
butterflies congregate into bands
and fly southwark. starting from
Canada about the end of August and
reaching the Gulf states about the
beginning of November. On the
West Coast they do not go so far
south and may winter in the neigh
borhood of San Francisco.
Having reached the end of their
southwark fight. the butterflies set
tie on trees, still keeping to their
large bands, and spend the winter
in a state of semi-hibernation. They
hutter around little on fine warm
days and in cold weather creep clos
er to the shelter of the trees.
The same group Of trees may be
used year after year by alternating
Monarchs, although the same indi-
viduals never return south second
time. One of the localities on Point
Pinos on Monterey bay, Calf. is
show place for visitors.
Return South in Great Swarms.
In the spring the bands begin to
break up, and the butterflies fly
northward individually, pausing here
and there to lay eggs as they go.
They start about March. reach the
level of West Virginia about April,
and Canada at the end of May or
early June. The return fight starts
after about three generations in the
middle states, two in the north, and
after a single generation in Canada.
So far as it is known, no Mon
archs are normally round in Can
ada and the northern United States