October 4, 2008: A warm day.  A morning heavy with dew.  A time of spectacular migration.

East of the Rocky Mountains, nearly the entire population of monarch butterflies (Danaus plexippus) travels south in autumn to overwintering sites in Mexico (a smaller population travels to Florida).  This migration brings a vast legion of fluttering wings through Texas, a state that serves as a funnel through which many of the insects move south from points north.

By late September and early October, White Rock Lake hosts a legion of monarchs every day as they stop to rest, to dine on autumnal nectar served from the season’s last flowers, and to drink dew squeezed from the air by cooler and cooler temperatures.

The lagoon that stretches inland behind the old paddle boat building seems to entice more butterflies to congregate than any other location around the lake.  It was there I stood beneath a bald cypress that hung heavy with monarchs, a cloak of orange wings fluttering.  The scene was nothing short of majestic and magical, an imaginary place leaping from the pages of fantasy.

The mystical feel of this phenomenon is made manifest in knowing it takes multiple generations for the monarchs to return north in spring.  Each butterfly only lives a few months, so the last generation born—having never migrated—will still know the way to the overwintering ground in Mexico, and that generation will make its way there and will live several times longer than all other generations by postponing their inherent need to procreate.

April 11, 2009: A warm day.  An afternoon of sunshine and breezes.  A calm before the storms of the evening.

In spring when the weather warms, the last generation from the year before will leave Mexico and make its way north.  Once they reach Texas (and perhaps Oklahoma), they will die, but along the way they will mate and lay the eggs of future generations.

It is those generations that will give rise to yet more generations, and months and lives far removed from the present will define the monarchs of summer.  Then in autum the migration will begin again with the last generation of the year, individuals who will be the hope for next year’s monarch population.

They migrate to a place they have never visited, the same place year after year, and they survive far longer than any other generation of monarchs.  They postpone mating in order to live half a year or more, in order to travel great distances, in order to overwinter in warmth so they can give birth to those who will continue the cycle.

I have seen them coming and going.  This year as I watched the female above deposit her eggs on every new sprout of milkweed that she could find, I wondered if—or perhaps hoped that—she was an individual I saw last year on her way south.  Unlikely, but a beautiful thought nonetheless.

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Photos:

[1] A male monarch resting near the firth.

[2] A female monarch sipping nectar from flowers along the water’s edge.

[3] Monarchs perching on a flowering shrub along the edges of the firth.

[4] A monarch sipping nectar from flowers.

[5] A monarch perched on a flowering shrub.

[6] A female monarch laying eggs on a milkweed sprout.

[7] A female monarch laying eggs on a milkweed sprout.