Flight of the Monarch: Cerro Pelón

Early English settlers gave the orange and black monarch butterfly its common name in honor of King William III, also known as “William of Orange” for his secondary title, Prince of Orange. The Spanish mariposa monarca also certainly reflects its regal appearance. However, our fascination with this butterfly is the product of not only its majestic display, but also the monarch’s epic journey of 2,000-3,000 miles each fall. Astonishing that an insect weighing perhaps half a gram can make such a journey. But perhaps even more amazing, it’s not the same butterfly that makes the flight each year.

Throughout the spring and summer, generations of monarchs have moved north following milkweed, their host plant on which they lay eggs. Hatching caterpillars munch through the leaves until it’s time to pupate and emerge as butterflies.

In the north as the days continue to shorten in August and the milkweed begins to die out, the last generation emerges in diapause, when reproduction is suspended. Sometimes called the “methuselah” generation, or at times “super” generation, this last generation in diapause lives eight to nine months as they head south on a trip of two to three months, traveling 25 to 30 miles a day on average.

At journey’s end, nearly every monarch east of the Rocky Mountains (>90% of all monarchs) arrives in the millions in the high-elevation east-west Transvolcanic Belt in south-central Mexico at the southern end of the Sierra Madre ranges. There they spend the rest of the winter, clinging to oyamel fir trees, as well as pines and cedars, while living on fat reserves accumulated on their trip south. They slumber on warmer south-facing slopes in clusters while the evergreen trees shield the butterflies, creating a microclimate chilly enough for hibernation but still warm enough that the monarchs do not freeze.

The fall this year has been dry for us, and monarchs only came through Tennessee in limited numbers. So instead, we’ll go to them. After all, as Annie Dillard says in Pilgrim at Tinker Creek, “beauty and grace are performed whether or not we will or sense them. The least we can do is try to be there.”

“You go first.” My horse handler, Vicente, has turned to me and now motions toward a saddled horse. I step up and onto a small wooden platform, fortunately provided since I’m not likely to succeed in swinging myself from the ground into the saddle. Instead, I place my foot directly in the left stirrup and lift my right leg over the horse to settle in the saddle. Vicente then leads us a short distance away so the next person can mount using the platform.

Photos: Sondra Jamieson

We’ve gathered for a ride up Cerro Pelón. We could walk of course, but we all agree to the horse ride that was recommended to prevent altitude sickness. Our group of nine horses and handlers will be ascending from the village of Macheros at 2,400 meters (7,900 feet) to where monarchs have gathered on the slope of the mountain at 3,000 meters or more (~10,000 feet).

Traveling by van from Mexico City in late January, Sondra and I, with friends Debra and Mark, cross from the State of Mexico into the State of Michoacán to the city of Zitácuaro on the northwest of the mountain range containing Cerro Pelón, which stands on the border between the two states. As we turn up a winding road into the mountains, we can see Cerro Pelón, which at a distance appears nearly bare on top as the peak rises above treeline. And so the name, which in English is literally “bald hill,” but locally is more appropriately “bald mountain,” reminiscent of the treeless balds on some peaks in the Great Smoky Mountains of Tennessee and North Carolina.

We traverse the mountain range to the east, crossing back into the State of Mexico to reach Macheros, home of the Cerro Pelón Butterfly B&B. I had first read about this enclave of the Moreno family and their efforts to save the monarchs and their community in a 2021 story on the Natural Resources Defense Council’s website, and so knew this was the best place to see the monarchs.

In 2012, Joel Moreno Rojas established the ecotourism site in Macheros at the entrance to the Cerro Pelón Sanctuary. By providing for locally based excursions to observe the overwintering butterflies, the effort creates job opportunities for the community, in contrast to the usual day-excursions from the cities that offer little benefit to the local economies. The B&B started with just three rooms and a shared bath connected to the family home where Joel was born, but since then it has grown to 14 rooms. 

To arrange for this trip, I had corresponded with Anayeli, Joel’s sister. Ana manages most of the details for guests of the B&B. At university in Mexico she studied Tourism, which includes a concentration on learning English, and later visited the U.S. to practice her language skills. Ana’s sisters, Oralia, Carolina, Veronica, and Margarita all help out at the adjacent restaurant run by Rosa, the mother of the family’s ten children, five boys and five girls. At Doña Rosa’s we had some of the best meals during our time in Mexico.

After settling in our rooms, we gather on the roof patio of the B&B’s main building where Joel had recommended watching the sunset. Amy Thoren is already on the rooftop when we arrive. From Illinois, she’s volunteering at the B&B for a couple of months before returning to her native plant nursery and ecodesign business she calls The Well Fed Caterpillar. Joel joins us, and while we enjoy the setting sun, he tells some of the history of the B&B. “When we first started in 2012, we were working as JM Butterfly B&B, and we kept that name for almost ten years, until recently we decided to update the name. I asked the staff for suggestions on what to rename the B&B and we all decided on ‘Cerro Pelón.’” While the ecotourism business provides tours to three locations, including El Rosario and Sierra Chincua, the Cerro Pelón Sanctuary “is the closest to our hearts. It’s the least developed and least visited of all the monarch sanctuaries.” The entrance is just a five-minute walk from the B&B. “I never get tired of seeing them (the monarchs),” he says, “I’m fortunate to live in such a beautiful place.”

The next morning after breakfast at Dona Rosa’s, we meet for an orientation with Joel and Amy. Joel summarizes the monarch phenomenon before we walk to the sanctuary entrance. “In the fall, nearly the entire North American monarch butterfly population that lives east of the Rockies starts a 3,000-mile journey to our small area of high-altitude tropical forest in Mexico’s trans-volcanic range. Millions of them return to the same trees in the same forest every year.”

When all of us have mounted, we head up the mountain with our handlers leading the way on foot. A family has joined us, and so we’re now seven. We also have Rogelio as a guide along with Amy, who are both experienced horse riders and do not require handlers. At times, Vicente serves as a guide, but this morning he’s tasked with leading the group while handling my horse. All of the Moreno siblings participate in the ecotourism enterprise; both Vicente and Rogelio are Joel’s brothers.

A foal runs alongside my horse. “We have another horse with us,” I say to Vicente.

“Si,” Vicente responds. “You are riding his mother. He is still nursing.”

This is not a simple walk up the forested mountain, and it’s been some time since I’ve been on a horse. So I’m glad Vicente has the lead to control the mare. Several paths braid the trail, and he chooses the best route between the trees as I concentrate on staying firmly in the saddle while hanging onto the pommel, especially when the going gets steep.

At times the route has become a trench with frequent use, and my horse occasionally falters over a loose rock or exposed tree root. With all the horses similarly lurching up the mountain, they kick up a dust cloud in this dry season. At first Vicente and I are in the lead, so I don’t have much dust to contend with. However, as the foal attempts to keep up with the mare, he’s getting in the way of the other horses and there’s a momentary scuffle with Sondra and others hanging precariously on to their horses. So Vicente holds back my horse with the foal alongside to clear the way for the others. Now that I’m in the rear, I pull my bandana over my nose and mouth to filter at least some of the dust.

After an hour of ascending the mountain, an occasional monarch darts by as we near the colony. At a small shelter in a clearing we dismount, again on a wooden platform. Some of the reserve’s stewards have gathered nearby, a few to accompany us. The Cerro Pelón Sanctuary has three rangers hired by the government and six forest guardians supplied by the Morenos’ nonprofit Butterflies & Their People, which they established to help monitor the sanctuary and discourage illegal logging. Since unemployment impels desperate people to take a log or two from the forest to sell for lumber, the nonprofit provides alternative income in an effort to reduce the logging. In addition to the work of the rangers, the nonprofit’s guardians “patrol this mountain every day,” Joel has told us, “so we always have up-to-the-minute information on colony location and behavior.” Another of the brothers, Patricio Moreno, now manages the nonprofit, which is totally supported by donations. The last brother, Melquiades, named after their father, also participates in the ecotourism business, helping out on tours.

The patrolling guardians from Butterflies & Their People have dramatically reduced the illegal logging simply with their presence. They also maintain the trails, remove trash, and monitor the monarchs. They note the time of the butterflies’ arrival, locate the colonies, and report when the colonies change locations, which can happen on warmer days when the butterflies are more active.

We’re in luck; this is one of the warmer days. The monarchs will likely take to the skies. Freddy, one of the young horse handlers, leads us on foot to continue the ascent to the colony.

We first notice gatherings of 10, 20, 30 monarchs at a time on flowering plants, numbers that would have astonished us anywhere else. Looking into the forest canopy, I see a hundred or more flitting among the pines and cedars mixed in with the oyamel firs. I reach up to a branch and examine a shoot from an oyamel branch with its blue-green needle-like leaves.

“We need to be quiet from here on,” Amy says as we approach the colony, “so we don’t disturb the monarchs.”

As we arrive, thousands, tens of thousands congregate on the trees’ lower branches on a slope below the top of the mountain. Peering more closely into the depths of the forest, I make out the dark masses of countless butterflies. Resting in those masses, the monarchs’ wings are closed, so the mostly the black and white of the under wings are visible, causing the clusters to look like dead leaves.

As we watch, the clouds yield to a patch of blue. The sunshine warms the huddling masses, and individuals whirl out of the crowded forms and take to the air. We look up, enthralled at a swirl of orange and black monarchs against a backdrop of blue sky and white clouds.

The rangers have roped off the colony to prevent us in our eagerness from getting too close. So we too huddle, in reverent silence, along the line of the rope, witnesses to the unimaginable.

Sondra and I sit on the ground together, awestruck. All who see such wonder struggle for words.

Amy quietly joins us as we notice some dead monarchs on the ground where we sit. “Do you know how to tell male from female?” she asks. Coincidentally, Sondra is holding both a male and a female. “The female has thicker veins that outline the wing’s cells. And the male has two small black dots, one on each hind wing.” These I later learn are vestiges of scent glands that are perhaps no longer needed and are slowly being left behind in the persistent progress of evolution.

All to soon, it’s time to retreat. Other families have arrived, and we yield to allow them time with the monarchs.

Sondra and Mark disappear down the trail on their horses while I wait to mount. The family has also left. Debra has now mounted, and I’m the last so Vicente and I are in back again with the foal. Rogelio and Amy bring up the rear to ensure we all make it down safely. At times that’s in question as we descend steeply, leaning back in the saddle to keep from slipping forward on the horse while grasping the pommel and gasping through our bandanas. But down we come.

Once back, Vicente leads my horse to a concrete bench to dismount. My legs are a bit wobbly after the harrowing descent, and Vicente steadies me as I step to the ground. We’re all laughing, happy to be down, but grateful for the adventure. As Vicente leads his horse away, I wave and call out. “Vicente, gracias amigo.” He smiles and waves in return.

At the B&B, Joel emerges to ask about our trip, “Sorry I was too busy to go with you today. How was it?” In response, our voices overlap with the excitement of what we have seen. “That’s what I like to hear.” Ana, also unable to be our guide this day, later tells me when comparing the sanctuaries, “Cerro Pelón feels more like home.”

Monarchs are measured in the number of hectares of trees occupied by the butterfly clusters in mid-December. One hectare is 2.47 acres. Estimates for the number of monarchs per hectare vary considerably; however, it’s still the accepted way to judge relative population growth or decline. For the 2021-2022 count, monarchs covered a total of about 3 hectares (7.4 acres). When they were a billion in the 1990s, they occupied about 20 hectares (~50 acres). Six hectares (~15 acres) is thought to be the extinction threshold; below this number resides the potential for the migrating subspecies to disappear. The primary pressures are loss of habitat for overwintering adults and loss of host plants for caterpillars on their trip north in spring.

While the mountain forests in Mexico are threatened by clearing for agriculture, as well as illegal logging within the monarch reserve, a more serious threat to the migration is lack of food sources in U.S. through which the eastern population must travel. Conversion of native prairie to agriculture, roadside mowing, herbicide use, and development eliminate milkweed and other native plants that provide essential food for the butterflies and their caterpillars. Efforts by conservation organizations to restrict herbicides and replant milkweed are ongoing.

Day two and one more horse ride. Sondra and I, along with Mark and Debra plus two other visitors, have been taken by van to the more distant El Rosario Sanctuary. Our guide Rogelio drives, and this time Ana also serves as guide. Arriving at the sanctuary entrance, she leads us up from a plaza encircled by vendors catering food and trinkets to the families and tourists who have come to see the monarchs. El Rosario has the largest monarch colony and easier access and so attracts many more visitors than Cerro Pelón.

Again we step onto a platform to mount our horses and be led up Sierra Campanario. The trail is not as rough, and the ride not as long, maybe twenty minutes. Folks acclimated to the high elevation can just walk up without too much difficulty, and that is what Rogelio does while Ana rides with us.

We soon dismount in a meadow. Here, we leave our horse handlers because we’ll walk back on a well-maintained path that descends the mountain, sometimes on concrete steps. Ana takes the lead and we follow the rest of the way through the oyamel forest on a fairly level trail. She turns to us. “We need to be quiet as we enter the sanctuary.”

And indeed, just as at Cerro Pelón, this seems a holy place. The towering oyamel firs filter the sunlight, casting cathedral beams onto the mountainside where monarchs have gathered in a massive colony of tens, hundreds of thousands. Perhaps fifty people have gathered in silence, in reverence.

The warming sun encourages the butterflies, and they stir from their roosts to “cascade” from the trees in search of nectar or “stream” down the mountain to find water before returning to shelter.

Several of us stop our picture-taking to sit on the ground and simply accept the phenomenon before us. Ana quietly sits behind us. Later she tells me, speaking of being in any of the sanctuaries, “When I’m here, I never want to leave.” Eventually we all must depart, but for these grateful moments we look up to monarchs filling the sky. The butterflies flutter overhead as they have for thousands of years. A constantly changing kaleidoscope of black and orange against blue.

© Russ Manning. All Rights Reserved.

An ebook of much longer text and complete references for Flight of the Monarch, Cerro Pelón is available from amazon.com.