What type of tours does Copper Moon Travels offer?

Copper Moon Travels offers deeply meaningful, culturally immersive small group journeys throughout Mexico. Our tours include Día de Muertos experiences, Semana Santa processions, monarch butterfly sanctuaries, birding excursions, Copper Canyon explorations, weaving traditions, and artisan collective visits.

Where does Copper Moon Travels operate?

Copper Moon Travels operates throughout Mexico, specializing in culturally rich destinations including Oaxaca, Copper Canyon, and other regions known for their Indigenous communities, natural landscapes, and living traditions.

Are Copper Moon Travels tours suitable for solo travelers?

Yes! Our small group tours are perfect for solo travelers looking to connect with like-minded explorers while experiencing authentic Mexican culture in a safe and welcoming environment.

How does Copper Moon Travels support local communities?

We work closely with Indigenous communities, local artists, master weavers, and community guides, honoring traditional protocols and supporting community-centered tourism initiatives throughout Mexico.

What makes Copper Moon Travels different from other travel companies?

Copper Moon Travels creates deeply meaningful journeys that go beyond conventional tourism. We invite travelers to experience Mexico as respectful participants in its rich and living culture, fostering authentic cultural exchange and meaningful human connection.

INTERGENERATIONAL MIGRATION: WHY MONARCH BUTTERFLIES INTRIGUE THE WORLD

coppermoontravels
Jun 30
8 min read

Monarch Butterflies at a Private Reserve

Photo by J. Bjarnason January 2026

Every November, something spectacular happens in the mountains of central Mexico – a phenomenon that still leaves scientists scratching their heads. Millions of monarch butterflies, some weighing less than a paperclip, arrive in the oyamel forests of Michoacán and the State of Mexico, having flown up to 4,500 kilometers from as far away as southern Canada. What makes their enigmatic journey so captivating is the fact that none of them has ever made this trip before. Their great-great-grandparents made it the year before, but that generation died months ago, thousands of kilometers to the north. Unlike salmon who return to their own spawn-streams, or birds who migrate many times over a lifetime, the intrigue of the homing instinct of the monarch butterfly surpasses these migrations because it is inter-generational.

This is one of the most studied insect migrations on the planet, and yet large parts of it remain genuinely mysterious. Here's a glimpse into what researchers do and don't know, and why the monarch butterfly biosphere in Mexico matters far beyond its own borders.

Monarch Caterpillar at Rancho San Cayetano, Zitacuaro Michoacan Mexico

Photo by J. Bjarnason March 2026

THE METHUSELAH GENERATION

Most monarchs live short lives. The three or four generations born each summer survive only two to six weeks as adults — just long enough to mate, lay eggs, and die. But the generation born in late summer is different. Triggered by shortening days and cooling temperatures, these butterflies enter a state called reproductive diapause: their hormones suppress sexual maturity, and the energy that would normally go toward reproduction gets redirected into fat storage instead.

This "Methuselah generation" is visibly larger than the other generations, but what is also bewildering – they live between seven to nine months — more than ten times longer than their parents and grandparents. It's this generation that completes the entire flight south, overwinters in Mexico, and then begins the journey back north the following spring before finally breeding and dying somewhere in Texas or the Gulf Coast states.

The southbound flight takes roughly two to three months, covering between 50 to 100 kilometers a day when the wind currents are favourable. The return to the north is a different story entirely — and a much slower one, because it isn't completed by a single generation. The Methuselah butterflies who return north only make it partway, to the Gulf Coast region, where they lay eggs and die. From there, it takes two to three more short-lived generations, each pushing further north to fully repopulate Canada by early summer. The whole northward recolonization process spans four to five months , which is longer than the southbound flight, despite the similarity of distance travelled.

Female Monarch Butterfly at El Rosario Reserve, Michoacan Mexico

Photo by J. Bjarnason February 2025

MONARCH NAVIGATION

How does a generation that has never made this trip find its way to the same patch of forest its ancestors used? Part of the answer is found in their antennae.

Monarchs rely on a time-compensated sun compass, which is essentially an internal clock paired with the position of the sun that lets them maintain a consistent southerly direction throughout the day, adjusting for the sun's movement across the sky. This system is housed in their antennae, not just the brain.

The question remained: If monarch butterflies rely on the sun for their migration, what happens on overcast days?

In 2014, scientists conducted a study using tethered butterflies in a flight simulator. The findings were conclusive: Migrating monarchs possess a magnetic compass that is light-dependent, relying specifically on ultraviolet-A and blue light between 380 and 420 nanometers to function. The molecules are light-sensitive proteins clustered in the antennae, called cryptochromes, the same structures that house the sun compass.

This magnetic compass appears to function as a backup system, used mainly when sunlight isn’t available, rather than being the primary tool monarchs rely on for their day-to-day southward flight. A more recent 2025 study tested monarchs under magnetic field conditions that mimicked the precise coordinates of the Monarch Butterfly Biosphere Reserve, as well as select locations within a flight range of three days to the north and south of it. Even when exposed to the overwintering site's exact magnetic signature, the butterflies kept orienting south rather than recognizing they had "arrived." In other words, the magnetic sense seems to help monarchs hold a general direction and notice if they've drastically overshot or undershot their goal — but it doesn't pinpoint the specific grove of oyamel trees their ancestors used. How monarchs achieve that final, precise homing instinct is still a question that continues to baffle scientists.

Monarch butterflies basking in the sunshine in a private reserve

Photo by J. Bjarnason January 2026

WHY OYAMEL FORESTS, SPECIFICALLY

The oyamel fir (Abies religiosa) forests where monarchs overwinter occupy a narrow and fragile ecosystem. Researchers have found that the forests monarchs choose share important consistencies: high elevations, typically above roughly 2,890 meters; close proximity to a stream or water source, moderately steep slopes and a south-southwest-facing orientation. The colonies also choose forests neighbouring glades, or meadows, where shrubs, grasses and wildflowers thrive but trees don’t grow.

The dense oyamel canopy, which is constantly threatened by illegal logging, is important for climatic changes throughout winter, as the monarchs huddle closely together, using the needle-like foliage as a blanket, only to disburse when temperatures are warm and allow them the liberty to fly away from their colony independently. A denser canopy also provides more condensation, which is important when it is cold, as monarchs need moisture to avoid dehydration. Monarch butterflies are cold-blooded and can only fly when their body temperature is around 25-30 degrees Celsius, so on cold days when they cannot fly, that moisture in the trees is crucial for their survival. One last threat to monarchs who discover thinned-out forests upon arrival is their exposure to inclement weather, such as rain and hail that is common over winter months.

Dr. Pablo Jaramillo Lopez (right side) with monarch enthusiasts

Photo by J. Bjarnason February 2026

A COLOSSAL STORM OF DISASTROUS MAGNITUDE

Between March 8-9, 2016, a catastrophic storm descended on the monarch biosphere, wreaking havoc on the monarch population just weeks before their annual departure north. The initial reports estimated a loss of approximately 6.2 million butterflies of the approximate 84 million overwintering that year, roughly, a 7% death toll. Etymologist Dr Lincoln Brower (September 10, 1931- July 17, 2018) and Dr. Pablo Jaramillo Lopez conducted a follow-up study, which they co-authored and published in 2017. Their conclusive data found the mortality rate to be closer to 31% in Sierra Chincua, 38% in Cerro Pelon and more than 40% in El Rosario.

What made this storm so unprecedented wasn’t the temperature, but the winds that toppled thousands of oyamel firs, destroying the canopy where the monarchs resided. With the absence of their canopy to keep them safe and warm, they were battered by sleet, hail and snow, causing them to freeze to death. This tragedy was compounded by the approval of “salvage logging,” which countered the forests ability to naturally regenerate.

Mark Garland of Project Monarch shows our group how trackers are attached to monarchs. 2025 marked the first year our guests had the opportunity to participate in citizen science through this ingenious technology, tracking several monarchs between 14 excursions and 4 unique colonies.

Photo by J. Bjarnason February 2026

PROJECT MONARCH, CITIZEN SCIENCE & YOU

Scientists have long tracked butterflies with small paper tags that were glued to a wing, with a phone number and a hope that someone would eventually find the monarch and report it. Locating a monarch with one of these tags was like searching for a needle in a haystack, nevertheless, an important part of pioneer research. This changed dramatically in 2025, when Project Monarch made citizen science a far more tangible and effective way for common folk to make important contributions to scientific data collection.

A standard GPS chip weighs more than a gram, which is more than an entire monarch butterfly. For years, this made true real-time tracking of an individual monarch's flight path technically impossible. A collaboration of more than twenty research and conservation organizations, led by Cellular Tracking Technologies and the Cape May Point Arts & Science Center, solved the weight problem with a new generation of ultralight, solar-powered transmitters weighing less than a grain of rice. The most clever part of the system is the receiver network: rather than relying solely on a sparse set of dedicated listening towers, the tags utilize Bluetooth, meaning any smartphone with location and Bluetooth can receive signals, in effect crowdsourcing one of the largest wildlife-tracking networks ever created.

In fall 2025, more than 400 monarchs were fitted with these transmitters as part of an initiative called Project Monarch. The first tagged monarchs to reach the Michoacán reserve completed a journey of more than 4,000 kilometers in just 43 days. Anyone curious can follow individual butterflies in near real time through the free Project Monarch app.

The results of this app have already rewritten some assumptions about migratory patterns, for example, one tagged butterfly was tracked flying down the eastern seaboard of the United States, across the Caribbean, and into Mexico via Veracruz, a path not previously well documented. Another monarch defected to Cuba, never to be heard from again, while another flew over the Rocky Mountains to join a colony in California. During one of our February tours, we tracked a monarch in Sierra Chincua that was scanned at El Rosario reserve the following day, confirming movement between the colonies and adding intrigue as to when and why they move within the biosphere and how they know where the other roosts are located.

Male Monarch in private reserve in the Monarch Butterfly Biosphere

Photo. by J. Bjarnason March 2026

A LIVING LABORATORY, NOT JUST A POSTCARD PHOTOGRAPH

It's easy to think of the Monarch Butterfly Biosphere Reserve as a seasonal spectacle — and it is genuinely spectacular, branches bending under the collective weight of thousands of butterflies, the air filling with the soft sound of wings as the afternoon sun warms the colony. It's also one of the most active frontiers in migration science, where decades-old questions about sun compasses, magnetic senses, and theories around inherited navigation and the transmission of knowledge within this inter-generational species are still being tested, revised, and occasionally challenged by new technology.

What's clear is this: the questions that remain unanswered are not minor, but more reason for further scientific research. Nobody yet knows precisely how a butterfly that has never been to Mexico locates the same patch of forest its great-great-grandparents used. That mystery is part of what makes standing beneath an oyamel grove during the overwintering season feel less like sightseeing and more like watching biology and creation in progress — happening in real time, in ancient forests, with real stakes for a species whose population has fluctuated dramatically over the past two decades and continues to face existential challenges that determine whether or not this phenomenal migration continues.

Female monarch feeding on nectar at Sierra Chincua Reserve, Michoacan Mexico

Photo by J, Bjarnason January 2026

EXPLORE OUR 2027

MONARCH BUTTERFLY

TOUR OPTIONS

Curious to visit the monarch overwintering colonies for yourself? Copper Moon Travels runs small-group tours into the heart of the Monarch Butterfly Biosphere Reserve led by award winning research scientist Dr. Pablo Jaramillo Lopez, who worked with and co-authored the 2017 mortality study with Dr. Lincoln Brower, and who has spent his career researching various aspects of monarch habitats. This is a rare opportunity to get educated about a myriad of facets impacting monarchs, from their biology, obstacles they face, solutions for mitigating the harms of human impact on their migration, the controversies over whether breeders should cage-raise or wild-raise monarchs and more. We offer different experiences from 2 – 12 nights, some of which include other interests, such as historical villages, colonial history, artisan studios and the awe-inspiring Grutas de Tolantongo Hot Springs. We also offer private tours for solo travelers, family and friends who prefer exclusivity.