Monarchs Head South Toward an Uncertain Future

By Anya Tyson –

If I went outside right now, hopped in the car, and started driving, it would take me 45 hours to reach the Monarch Butterfly Biosphere Reserve in Michoacán, Mexico, some 2,823 miles away. Though I badly want to see the groves of sacred firs (Abies religiosa) quivering and dripping with orange and black wings, I’m not leaving today. For now, I am content to have witnessed one of this year’s migrants emerge from its chrysalis.

When I first saw the chrysalis I thought the tiny, metallic gold markings seemed suspiciously intricate for a mere caterpillar’s changing room, and peered at them as if they might instead be explained by sci-fi alien manufacture. Apparently, these spots allow oxygen to reach the developing structures and organs of the enclosed butterfly.

The next morning, in the span of about 15 minutes, this female butterfly inched downward out of her chrysalis, re-distributed fluids from her distended abdomen to unfurling wings, and washed her face in preparation for what was to come. Her autumn journey to the Transvolcanic Mountains of central Mexico— if she can complete it—will take two months. To put this voyage in perspective, it is around seven times the distance traveled by caribou as they migrate from summer habitat to winter haunts. Caribou are billed as the land mammal with the longest migration in North America, whereas the Monarch is a butterfly whose flight has been described as “slow and sailing.”

The spring migration of Monarchs to New England is carried out by five different generations, each pushing north at distances more commensurate with their two-to-four-week lifespan and the floating nature of their flight. Monarchs hatched in late summer are among the generation that will live for several months to travel an incredible distance by putting their reproductive tendencies on pause, or rather, on diapause.

Diapause for the Monarch is a sort of flying hibernation that allows the butterfly to extend its lifetime, endure migration, and make it through the winter. Unlike hibernation, however, only specific environmental conditions can induce an organism to enter or exit diapause. In the case of a Monarch, when the days are long enough and the temperatures are just right, the overwintering butterfly shakes herself reproductively awake, mates, and then travels a few hundred miles north to lay her eggs on milkweed before dying.

Sadly, the odds for our particular young Monarch and her progeny are dismal. She faces habitat loss, changing environmental cues, invasive species and car windshields along the many miles of her journey. The population of Monarchs east of the Rockies is estimated to have declined by 90% since its level in 1995.

Nevertheless, government agencies, non-profit organizations, and concerned citizens are mobilizing to try to prevent the migratory Monarch’s extirpation. As with many environmental issues, large-scale actions such as policy change will be crucial. However, because the plight of the Monarch also plays out in our backyards, opportunities to help are close to home. You can plant native milkweeds to benefit individual butterflies. You can join other citizen scientists in supplying data to strengthen and inform the measures we take to protect Monarchs; check out monarchwatch.org.

The first, beautiful moments of a young female Monarch reawakened my awe and concern for this species. Instead of being crushed by the terrible thought that, if Monarchs were to go extinct, this mystical experience might become a mythical one, I am spurred to share the urgency of the situation. Urgency is more powerful when it is underpinned by wonder. And though this combination might seem like a fragile set of wings with which to entrust the fate of a species, I take comfort in the thought of Monarchs fluttering south towards Mexico, unfazed.

Anya Tyson is a first-year Field Naturalist student