Pirate lizards: how three-legged lizards thrive in the wild

The project started with one lizard. During a study of natural selection on brown anoles on islands in the Bahamas, every lizard had been caught, measured, marked and released. A year later Jonathan Losos was chasing one particularly nimble individual through the branches. Only once it was in hand did he realize that it was missing its entire left hind leg. A year earlier it had had all four. In between, the leg had been lost, the wound had healed, and the lizard was, as our paper puts it, “fat and sassy.”

Over the years, more of these animals turned up, and conversations with colleagues revealed that field biologists working on many different lizards had seen the same thing. So we pooled the records.

What we found

Together with field biologists around the world, we documented limb loss, from a single foot to an entire leg, in 58 lizard species. Every case had healed, and many of the lizards looked robust and healthy. Limb-deficient lizards are rare, typically less than 1% of a population. Yet where we could measure them, they often had body condition, sprint speed and survival comparable to their four-legged neighbors.

Why it matters for evolution

Limbs are one of the classic examples of natural selection fitting animals to their environment. Across lizard species, limb length tracks habitat closely, and even small differences between individuals can affect how fast they run and whether they survive. By that logic a lizard missing a whole leg should not last long.

It may be said that natural selection is daily and hourly scrutinizing, throughout the world, every variation, even the slightest.
Charles Darwin, 1859

Three-legged lizards suggest that selection is not always that relentless. Traits that look essential may, at least some of the time, matter less for survival than we assume, which in turn shapes how we should design and interpret studies of adaptation in the wild. Is natural selection always as omnipresent as Darwin envisioned it to be? Our long-term work on Lizard Island, where selection comes and goes from season to season, points in the same direction.

The paper, “Pirates of the Caribbean (and elsewhere),” was published in The American Naturalist in 2025 and made the front page of the New York Times print edition. James Stroud and Jonathan Losos also wrote about it for The Conversation.

In the news

• The New York Times 'Pirate Lizards' Can Get Around on 3 Legs October 2025 · Front page of the print edition
• Science 'Pirate lizards' can adapt to survive on just three legs 2025
• Smithsonian Magazine These 'Pirate Lizards' Thrive With Three Legs October 2025
• The Conversation 3-legged lizards can thrive against all odds, challenging assumptions about how evolution works in the wild 2025 · by James Stroud

Read the research

• Pirates of the Caribbean (and elsewhere): Three-legged lizards and the study of evolutionary adaptation. The American Naturalist (2025)
• 3-legged lizards can thrive against all odds, challenging assumptions about how evolution works in the wild. The Conversation (2025)