Remarkable Butterfly Travels 15,000 Kilometers and Pushes the Limits of Animal Migration

After nearly a decade of research and multiple international collaborations, Chilean scientists—including Dr. Hugo Benítez of the One Health Institute at Universidad Andrés Bello (UNAB)—have unraveled the migratory journey of Vanessa carye, an iconic butterfly species found from Venezuela to Tierra del Fuego.

The research, published in the journal Molecular Biology and Evolution, revealed that this species undertakes a journey of up to 15,000 kilometers (round trip), placing it among the most remarkable migratory butterflies on the planet.

The study was led by Dr. Hugo Benítez, researcher at the One Health Institute at Universidad Andrés Bello, the Millennium Institute BASE, and the Cape Horn International Center, together with his team from the Evolutionary Ecology and Morphometrics Laboratory (EME Lab). The findings were supported by genomic and morphometric analyses that allowed researchers to trace the species across dramatically different environments.

“Unlike other animals, it is nearly impossible to equip butterflies with tracking devices because of their fragility and high risk of predation,” said Professor Benítez.

As a result, the researchers turned to innovative approaches such as the analysis of single nucleotide polymorphisms (SNPs), which revealed high levels of heterozygosity and gene flow across thousands of kilometers.

This means that despite traveling more than 7,000 kilometers across deserts, rainforests, mountain ranges, and steppes, Vanessa carye maintains remarkable genetic and morphological uniformity. Neither its wings nor its physical characteristics show significant differences, suggesting constant connectivity among populations and an extraordinary capacity for adaptation. These findings formed a significant part of the doctoral dissertation in Systematics and Biodiversity completed by Dr. Amado Villalobos (University of Concepción), a member of EME Lab.

The Remarkable Migratory Strategy of Vanessa carye

Historically, the migratory status of Vanessa carye has been the subject of scientific debate. Although the butterfly has a broad distribution across South America (approximately 7,000 kilometers) and has been observed at extreme altitudes and in remote locations, some researchers have argued that its wide distribution could be explained by a strong dispersal capacity rather than by a defined migratory behavior.

However, by analyzing the butterfly’s genetic structure, diversity, and wing morphology, Dr. Benítez and his team found evidence that Vanessa carye possesses characteristics consistent with a migratory species. Moreover, they identified two parallel migratory routes: a coastal route and an Andean route.

Together, these routes allow the species to maintain genetic connectivity among populations throughout South America, creating an ecological corridor that transcends political boundaries and ecosystems. This dual-route strategy confirms that Vanessa carye is not only highly resilient, but also employs a migratory strategy comparable to that of birds such as swallows and even large marine mammals.

“We are looking at one of the most remarkable migratory butterflies on the planet. Not only have we confirmed that it can travel distances comparable to those of birds and mammals, but we have also discovered that it maintains its genetic and morphological identity across the entire continent.”

“This discovery changes the way we understand this insect and provides key insights into how species cope with extreme and changing environments in the context of the climate crisis and landscape transformation,” added the UNAB researcher.

Having confirmed the migratory capacity of Vanessa carye, the research team is now continuing to investigate the movements of other South American butterfly species, with the goal of deepening our understanding of the ecological and evolutionary processes that enable these insects to connect ecosystems separated by thousands of kilometers.