March 2014 - Parks & Recreation - 58

MONARCH BUTTERFLIES

Monarch life-cycle play sculptures add a whimsical touch to the Nina Mason Pulliam
Audubon Center in Phoenix, Arizona's Rio Salado Habitat Restoration Area. Kids can
actually climb inside the chrysalis to play.

when they came back to lay eggs on
milkweed plants for the next generation to make its way northward.
Perhaps no other plant, animal or
insect has done more to excite the
imagination of children. Egg, larva,
pupa, adult - metamorphosis! It's
one of the first mysteries of nature we
learn as children. The transformation
that monarchs go through from egg to
adult inspires wonder in all who witness it. " Monarchs provide a connection to nature unlike almost any other species, " says Karen Oberhauser,
professor of conservation biology and
director of the Monarch Lab at the
University of Minnesota, and chair of
the Monarch Joint Venture Steering
Committee. Laurie Adams, executive
director of the Pollinators Partnership, concurs. " A lot of people had a
personal experience with this butterfly in their childhood, " says Adams.
" They saw them at a time in their life
when they had a sense of wonder. "
Oberhauser says monarch butterflies
continue to matter to people as adults.
" They not only tell us what is going
on in the natural world, " she says,
" they make us care. "
However, monarch numbers have
plummeted, and a just-issued report
by the World Wildlife Fund, the
56

Parks & Recreation

Mexico Department of the Environment and the Protected Natural
Areas Commission about last year's
overwintering population estimates
the species is in " grave danger. "
Some scientists fear the northward
migration of monarchs may just end
if there are not sufficient numbers to
reproduce and adequate habitat for
the migrating insects that remain.
Monarchs in Crisis
The challenges facing this intrepid wanderer are many. Monarch butterflies
embark on what is considered one of
the great migrations in all of nature,
with each round trip involving multiple
generations of insects that return to ancestral wintering grounds, never having
known or learned from previous generations how to get there. The first generation moves northward (from Florida,
Mexico or southern California) in February and March. Females lay eggs on
the leaves of milkweed plants and then
die soon after. The larvae, or caterpillars, from the next generation of monarchs pupate (spin a chrysalis), and after
10 days or so transform into butterflies
that continue to move northward, perhaps for hundreds of miles more where
the adult females find milkweed plants
and repeat the cycle. But the migration

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is not over then. The fourth generation,
which lives for six to eight months, up to
three or four times as long as preceding
generations, begins a thousand-mile or
longer flight south where the butterflies
four generations removed from the original return to ancestral wintering areas
to overwinter till the next spring and begin the process again.
At every turn, however, monarchs
face increasing threats to their existence. Monarchs must have milkweed
plants on which to lay eggs, which
then feed the larvae of the next generation. Milkweeds are common roadside plants and agricultural weeds
that are generally very hardy, but with
changing agricultural practices and
destruction of this plant's best habitat
areas, much of the milkweeds have
been lost, and therefore, so have the
monarchs.
Many of the monarchs that migrate
to the north cross the " corn belt " of
the United States, a vast area of fertile
farmland that encompasses more than
a dozen large Midwestern states. Corn
fields used to contain an abundance
of milkweed plants, and the Midwest
produced nearly 80 percent of monarchs that migrated to Mexico, most
of them from eggs laid on milkweeds
left growing in the corn rows. Since the
late 1990s, however, farmers have been
planting herbicide-resistant row crops,
often called " Roundup-ready " crops
after the trade name of the herbicide
glyphosphate that is applied to fields,
sometimes by planes and helicopters.
The herbicide kills the weeds but not
the crops, and worst of all, it also kills
all the milkweed plants, which can normally survive regular cultivating but
not the application of this herbicide.
Other insecticides, notably the neonicotinoids (which are implicated in
the large-scale die-off of bees), may
also affect monarchs by making the
milkweed leaves toxic to monarch caterpillars. " Even the leaves of milkweed

March 2014 - Parks & Recreation

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