For those of us who grew up in North America, the Monarch was the most recognizable of all butterflies. Large and brilliantly marked with a rich orange/gold and black pattern they could be seen by the thousands twice a year in their migrations between Canada and a single Mexican forest region. Their metamorphosis from a milkweed munching caterpillar spinning its cocoon to its emergence as a regal flyer was a staple of grade school science curricula.
But all of that is under a dire threat as populations collapse with the rapid alterations in their critical Mexican nesting grounds due to global climate change. A recent report on the Canadian Broadcasting System (CBC) explained:
Monarch butterflies appear headed for a perhaps unprecedented population crash, according to scientists and monarch watchers who have been keeping tabs on the species in their main summer home in Eastern and Central North America.
There had been hope that on their journey north from their overwintering zone in Mexico, the insect’s numbers would build through the generations, but there’s no indication that happened. Only a small number of monarchs did make it to Canada this summer to propagate the generation that has now begun its southern migration to Mexico, and early indications are that the past year's record lows will be followed by even lower numbers this fall. Elizabeth Howard, the director and founder of Journey North, a citizen-scientist effort that tracks the migrations of monarchs and other species, says one indicator for the robustness of the monarchs is the number of roosts they form in late August and September, something Journey North monitors throughout the migration periods. “During migration, monarchs form overnight roosts in places like Point Pelee or Long Point [in southern Ontario], where the monarchs are congregating before crossing the Great Lakes, places where people generally see huge overnight clusters of monarchs gathering.” Howard told CBC News that at this time in 2011, Journey North had already received 55 reports of roosts, followed by just 25 in 2012. This year, only 17 reports of roosts came in. “This is really a proxy for peak migration because this is where people see really large numbers of monarchs and we’re just not getting the reports, it’s looking pretty bad,” she says.
The monarch butterflies that are now flying south are the fourth generation of those that left the few hectares in central Mexico where millions of monarchs spend the winter.
Several years ago while I was working as a school custodian in Cary, Illinois, the visit of a lone Monarch on its southward migration, a pioneer, inspired a poem that was included in my 2004 Skinner House Books collection We Build Temples in the Heart and was also anthologized by Edward Searl in his compilation In Praise of Animals A Treasury of Poems, Quotations, and Readings.
Some of the science is fuzzy—a single insect does not make the whole epic journey, it takes four generations—but the sense of awe and wonder remains.
And to think we may be the last generation to experience it…
Later they will come,
the legions of Canada
on the edge of cutting cold,
backs scraping stratus slate,
arrayed in military majesty,
dressed in ranks and counting cadence,
squadron after squadron, an air armada,
single minded in their migratory mission.
when September sun lingers and
lengthened shadows hint ferocity to come,
the first glints of gold and black flit
with seaming aimlessness,
pushed here and there by the faintest zephyr,
the pioneers of a nation,
descended from Alberta prairies
and Minnesota Lakes.
One will linger
briefly on my shoulder
if I am blessed, then be off again.
Then, if she is lucky
she will pause to rest with
the millions along the bend of the Rio Grande
before finding a winter’s respite of death
amid deep Mexican forests.
And it will turn again next spring—
egg to larva,
larva to silken slumber
pupa to Monarch
Monarch to migration.
Oh ye proud Canada,
mute your boastful blare—
the mighty bow before true courage.