Even in a place like Madagascar, teeming with charismatic animals, the panther chameleon stands out. The adult males are known for their range of vibrant colors, from dark green to bright pink. The lizards’ colors and patterns vary depending on where they live, with different color “morphs” found only in certain locales. Chameleons living on the northern tip of Madagascar’s main island, for example, are usually green with red and orange stripes on their back, while those in the northeast Sambava region range from dark green to almost black and have reddish faces with black stripes around their eyes. (Females and younger males, meanwhile, are tan-brown with hints of pink or orange no matter where they’re found).

The lizards can further alter their colors to communicate their mood when confronting other males or courting females. Despite wearing their emotions on their sleeves, these chameleons have been hiding a surprising secret, according to a new study. The panther chameleon might not just be a single species, but as many as 11 different ones.

While studying the physics of chameleons’ color-changing abilities, biologist Michel Milinkovitch and his team decided to also look at the panther chameleon’s genes and see if they could explain its diversity of colors. They made two trips around Madagascar to track down, photograph, and take blood samples from hundreds of lizards.

By examining the lizards' DNA, they found strong genetic differences between the lizard populations, which suggests there are 11 distinct lineages of panther chameleon scattered around Madagascar that rarely breed with each other or even overlap. The researchers think that some or all of these groups might need to be considered separate species.

While their colors vary, these different species are physically similar, which helps explain how the different lineages could hide in plain sight for so long. Milinkovitch’s team also found that certain patterns and color features can help link individual lizards to the lineage it belongs to. One group, for example, is distinguished by its lips. They may be brown-yellow or bright white, but never become bright yellow like some other males’ lips do.

The team has made a classification key so that other researchers can ID species by sight instead of having to take DNA samples. This should help local authorities and conservation groups avoid cases of mistaken identity among the different lineages, which may require different resources and strategies to manage and protect.