Departing Manhattan on a cross-country flight, monarch butterflies head south each winter for rest and relaxation with a return trip booked for early March. Their destination? The welcoming warmth of central Mexico. Their lodging? A dense forest of sacred oyamel fir trees. When it comes to skipping town—and the cold—Central Park’s monarch butterflies go the distance.
The annual pilgrimage starts in southern Canada and the northeastern United States, when almost half a million monarchs head to Mexico to overwinter before their spring return. This stunning phenomenon, known as the great monarch butterfly migration, starts right here in the lush meadows and woodlands of Central Park.
There and Back Again
Before winter sets in, monarch butterflies—distinguished by their orange and black wings framed by white polka dots—leave Central Park for the Monarch Butterfly Biosphere Preserve in central Mexico. After a 3,000-mile, two-month long journey, these monarchs ultimately make their home in the Trans-Mexican Volcanic Belt pine-oak forests, clustering on branches of pine and oyamel trees.
From late October to early March, these insects bask and rest in the sunlight, their ornate wings blanketing the tree branches while tourists watch excitedly from below. As spring approaches, monarchs come out of their hibernation and mate before a remarkable, multigenerational migration north.
The first group of monarchs leaving Mexico stops to lay eggs on their journey back before they die; those eggs then develop into the next generation that continues north, repeating the same cycle. Like runners passing the baton in a relay race, four generations of monarchs are born and die over their spring return to North America (and Central Park).
The Marvelous Mariposa
The Central Park Conservancy’s Natural Areas team—made up of experienced naturalists, arborists, and ecologists—is well-synched to the miraculous biological clocks of these beautiful species. From spring through the end of fall, areas like the Dene Slope, North Meadow Butterfly Gardens, and Hallett Nature Sanctuary are flush with impressive blooms "that provide nectar to fuel adult monarchs for their journey,” explains Assistant Manager Alex Hodges.
These summer months spent in the Park are essential, as monarchs are fueling up for their next migration south and doing the important work of pollination. Pollination refers to the transfer of pollen between male and female plants, enabling the fertilization and production of seeds. An essential evolutionary process, pollination is largely dependent on the birds, bats, bees, and butterflies—or pollinators—that act as vectors between plants.
By moving the pollen that fertilizes plants and creates seeds, pollinators ensure the next generations of plant life that we depend on for joy, nourishment, and survival. Put simply, pollinators—alongside our Conservancy staff—keep our Park in bloom, improving the environmental health and happiness of New Yorkers.
Through the intentional planting and maintenance of native flowers, shrubs, trees, and grasses, the Conservancy’s Natural Areas team nurtures the spaces that monarchs and other pollinators rely on for sustenance and shelter. “The Park is a bright green patch in the middle of the City, which means our butterflies and other wildlife depend on it as a crucial pit stop” to eat, lay eggs, and rest between migration journeys, Alex explains.
His colleague Mimi Gunderson, a Natural Areas Technician, adds that “pollinators are specified to pollinate specific types of plants. For example, some species, like hummingbirds, have long tongues which are perfect for pollinating tubular flowers.” Monarch butterflies similarly have long, unfurling tongues, called proboscis, that enable them to feed on and pollinate specific flowers. Like two puzzle pieces fitting together, this interdependence between plant and pollinator ensures the survival of both species.
Mimi, Alex, and their team utilize herbaceous plants like butterfly milkweed, asters, and New York ironweed to create robust pollinator spaces, but stress that each plant in the Park plays an important role in a butterfly’s life cycle. Lesser recognized butterfly host species like the red oak tree, spicebush, and little bluestem grass provide a protective layer of foliage for caterpillars to feast on.
The Butterfly Effect
Despite the Conservancy staff’s work to create more butterfly-friendly spaces, monarch butterflies face broader existential challenges. Due to factors like deforestation, increasing global temperatures, and extreme variations in weather due to climate change, their populations are dwindling.
According to The New Yorker, “last winter, the area [monarchs] covered in the reserve decreased by fifty-three percent.” On top of that, fluctuating temperatures across the country “limited the growth of milkweed, the only plant on which they lay their eggs, and slowed the growth of caterpillars—all of which made later generations smaller.”
All the more reason to treat Central Park’s pollinator spaces gently. “While it can be very tempting to pick flowers in the Park or step into a wildflower meadow, remember that these plants are important for butterflies and other pollinators,” Alex cautions.
As the City thaws out and welcomes monarchs back to the Park this March, keep an eye on the pollinator spaces cared for by our Conservancy staff. The Dene Slope and Hallett Nature Sanctuary can be visited in person or virtually through our Weekly Walk series, and Park enthusiasts can sign up to volunteer in many of the Park’s gardens.
Looking for more ways to engage with our natural world? Try out birding or go for a solo walk to witness its wonders, and tag @CentralParkNYC with your photos. And as with all Park excursions, Mimi stresses, the best way to support wildlife is to “just observe and appreciate from a distance.” After all, these monarchs have come a long way.
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