Monarchs huddle together for warmth and security as they spend the winter in the oyamel fir forests of Mexico. © Jaime Rojo
By Emma Caton
Each year, millions of monarch butterflies make one of the most extraordinary insect migrations on Earth.
Wildlife photographer Jaime Rojo has documented these iconic butterflies for more than two decades. He’s witnessed their decline but also the inspiring work to save them.
High in the mountain forests of Mexico, millions of monarch butterflies blanket the fir trees.
They will spend the winter huddled together in these immense clusters. But each year the journey to return to these forests is becoming increasingly perilous as human activity closes in along the butterflies’ migration routes.
Jaime has been photographing monarchs for more than 20 years. His portfolio Migration of the Monarchs was highly commended in the sixtieth Wildlife Photographer of the Year competition.
Growing up in Spain, Jaime developed a passion for the natural world at a young age. He was particularly drawn to the biodiversity of Mexico and managed to get funding to study there.
Just three days after landing in Mexico City, Jamie got the opportunity to travel into the mountains to see monarchs at their wintering grounds. By this point, he was already a passionate amateur photographer and took his camera to document the experience.
Monarch butterflies gather in their millions on towering fir trees. Jaime’s image A Magnificence of Monarchs was a Wildlife Photographer of the Year finalist in 2017. © Jaime Rojo
“From that first visit, I was fascinated by the spectacle,” says Jaime. “When they take flight, it’s like the whole tree explodes with butterflies.”
“But you don’t just see it. You can hear the noise of their wings fluttering and feel the air current.”
“The first time you see it, you fall in love with it. I have returned to this site many times over the years. Every time I go, I see something new. It’s so magical, I never get bored.”
When Jaime decided to become a professional photographer, he focused his portfolio on the mountains surrounding Mexico City, a hotspot for biodiversity. Initially, he focused on the tiny volcano rabbit that lives on only a few mountains in Mexico. But he eventually switched to monarch butterflies and started photographing their winter sanctuary.
When the days begin to get longer around late February, monarch butterflies set off from their wintering grounds in Mexico and begin to fly north.
Along the way, they stop to lay their eggs on a flowering plant called milkweed. In just a few days, caterpillars hatch out of the eggs. They eat the milkweed to gain weight.
About two weeks later, the caterpillars begin a chrysalis stage, eventually emerging as butterflies. Remarkably, this new generation then continues the journey their parents began.
This butterfly relay repeats over four or five generations. Collectively, they fly up to 5,000 kilometres to reach their final destination in the northern USA and Canada. The monarchs stay here until late summer when the females lay a very special egg. This new cohort is referred to as super-generation monarchs. They’re larger than regular monarchs and can live up to eight times longer.
These powerful butterflies can fly all the way back to Mexico in a single generation. How they find their overwintering grounds in Mexico, having never been there before, has often puzzled scientists.
Many think the insects use a combination of the Sun’s location and an internal magnetic compass to stay on course.
The scale of this impressive migration only came to light within the last 50 years when researchers began tracking the monarchs.
Radio trackers help researchers follow and analyse monarch butterflies’ flight patterns in an effort to understand how they find their overwintering grounds in Mexico. © Jaime Rojo
“Until surprisingly recently, we didn’t know where the monarchs would spend the winter,” says Jaime. “Local people in Mexico knew about the winter colonies, but all the Americans and Canadians knew was that by early autumn, the monarchs would disappear.”
“There was speculation they might be migrating, so a Canadian scientist and his wife started tagging butterflies in the 1970s and discovered that they spend the winter in these forests in Mexico.”
“This has now been taken to a whole new level by an organisation called Monarch Watch. They train thousands of volunteers across North America to attach lightweight tags to butterflies, which are recovered at the wintering site in Mexico. This is invaluable for helping scientists learn more about the monarch migration.”
Over the last 20 years, Jaime has seen a noticeable drop in the number of butterflies arriving at the wintering grounds in Mexico.
Roads and light pollution are becoming increasing problems for monarchs during migration. Every year, thousands are killed by traffic, and many don’t stop to rest because of lights from cities. © Jaime Rojo
Monarch populations that spend the summer to the east of the Rocky Mountains once numbered in the hundreds of millions, but now they’ve declined more than 80%. The populations in western North America may have declined by as much as 99% since the 1980s.
“The first time I saw monarchs at the wintering grounds was in 2004 and the numbers were way more abundant than they are today,” says Jaime. “When you follow a species for a long time, you really notice these declines.”
“In the early 2000s, the colony stretched for 20 hectares of forest. This year, it was less than one hectare.”
Witnessing the drop in numbers, Jaime shifted from just documenting the pure beauty of the sanctuary. Now, he strives to tell the whole conservation story.
The drop in monarch numbers was initially attributed to the destruction of forests in the wintering sanctuaries in Mexico. But further research brought to light the perils the butterflies were facing all along their migration route.
Monarchs rely on milkweed as food for their caterpillars. Until the early 1990s, milkweed was widespread across the USA. Increased use of herbicides caused the decline of this important food source.
The forest habitat of monarch butterflies is very sensitive to changes in moisture. Nearby avocado groves use up a lot of water, which could have a harmful effect on this important habitat. © Jaime Rojo
Climate change is also a growing problem for monarchs, with extreme weather conditions becoming more frequent. Snowstorms can be lethal to the insects and hotter, drier summers will shift their suitable habitat further north.
“The year I was working on a story for National Geographic, there was a drought around southern Texas and northern Mexico,” says Jaime. “This meant many of the flowers that monarchs depend on during the migration did not bloom. As a result, the numbers of monarchs plummeted that year.”
Jaime wants his photography to communicate a story of hope and champion the work of countless people to protect the monarchs.
Scientists and local communities in Mexico have been working together to create new ways of restoring the forest. This includes an ambitious effort to move the oyamel fir forest further up the mountain.
The areas where the butterflies currently spend the winter tend to be 2,400 to 3,200 metres above sea level. A team of scientists is relocating trees to higher altitudes to prepare for the warming climate.
Scientists use flags to mark milkweed. This will help train an artificial intelligence algorithm to recognise milkweed from drone footage. © Jaime Rojo
“I think some of the most inspiring examples of conservation work is being done at an individual level,” says Jaime. “Many people along the migratory route have been replacing their tidy grass lawns with native grasses and flowers, including milkweed.”
“Monarchs need to stop every 100 kilometres or so to rest and feed. So, by planting native grasses, you are providing a small patch of habitat where the monarchs can stop, refuel and lay their eggs.”
“Throughout this project, I have met dozens of individuals, families and communities who are changing their backyards to protect the monarchs. That was very inspiring to see.”
These efforts have also been seen at a larger scale with farmers. Some have set aside large parts of their property to create a habitat for pollinators, including monarch butterflies.
“Monarchs are very resilient,” concludes Jaime. “As long as the habitat is there, they have a good chance of survival. When people look at my photographs, I want them to see that there is hope. We can save the monarchs, but we need to protect and restore the habitat on which they depend.”
Wildlife Photographer of the Year tells the incredible stories of life on our planet through powerful photography and expert insight.
Don't miss a thing
Receive email updates about our news, science, exhibitions, events, products, services and fundraising activities. We may occasionally include third-party content from our corporate partners and other museums. We will not share your personal details with these third parties. You must be over the age of 13. Privacy notice.
Follow us on social media