Some tropical butterflies live surprisingly long lives. Is it their high-protein diet?

Whereas most adult butterflies rely entirely on sugary nectar to fuel them, butterflies in the Heliconius genus have evolved to also eat pollen. Pictured here is an Agraulis vanillae. (Wikimedia Commons/ Christina Butler), CC BY Some tropical butterflies live surprisingly long lives. Is it their high‑protein diet? Published: August 3, 2026 7.31am EDT Share article Print article Butterflies are charismatic, colourful and cherished around the world. One of the most diverse groups of insects, with more than 19,000 described species, they inspire international organizations such as the North American Butterfly Association and the Xerces Society, as well as countless websites devoted to their identification, monitoring and natural history. This fascination is so widespread that it shapes the science we do. In our research, we’ve shown that people are far more likely to photograph and report some butterfly species than others, simply because they’re more colourful and look more interesting. That collective enthusiasm has transformed butterflies into one of the best-studied insect groups on Earth. Now, new research suggests butterflies are more than just pretty faces — they may hold clues to healthy aging. Our own research focuses on how organisms adapt to their environments and what these changes reveal about broader ecological processes. Jayme Lewthwaite has studied Canadian butterflies for over a decade, studying traits associated with their changing ranges. Arne Mooers is a comparative biologist, probing adaptation by considering differences between related species. Here we consider why exceptionally long-lived butterflies evolved in the first place, and what their biology might (and might not) tell us about aging generally. A butterfly that eats pollen An international team of researchers recently took a close look at one group of butterflies — the Heliconius genus — that have evolved lifespans many times longer than other butterflies. Part of this longer lifespan seems to be due to a unique adaptation: whereas most adult butterflies rely entirely on sugary nectar to fuel them, Heliconius butterflies have evolved to also eat pollen. This protein-rich food source is linked to slower physical decline, with older butterflies in this group maintaining muscle function far longer than their non-pollen feeding relatives. The researchers suggest this observation may help us understand aging in other species, including humans, by identifying mechanisms…