Tiny chameleons are big news

Brookesia chameleon

A slightly larger relative of the new species (picture by Frank Wouters)

It’s no secret that I adore chameleons. They look like toys designed to appeal to children who love animals – colourful, cute, with crazy eyes and super-powered tongues. And they change colour! What more could you want?

Well, how about a miniature chameleon so small it can sit on the head of a match? Thanks to the amazing island of Madagascar and a new paper by a group of German scientists, we now know there is such a creature. Although I’m amazed they ever discovered such a tiny, well-camouflaged little chap. And because science is the gift that keeps on giving, not only are these chameleons very cute, but they can also tell us some interesting stuff about tiny animals and how they evolve.

In fact the scientists found four new species of dwarf chameleons, which they describe as ‘striking cases of miniaturisation’. They’re also special because they’re found only in tiny areas of Madagascar, making them ‘microendemic’ as well as microscopic (well, nearly).

As the scientists point out (somewhat unnecessarily), ‘while the largest animals are generally well known, miniaturised species often go undetected, and striking new discoveries of dwarf species are not uncommon.’ But this type of research isn’t just about naming and describing an animal that’s new to science (if not to locals).

As the paper explains, the evolution of unusually small animals may actually lead to the development of new body plans – for example, some miniaturised species have lost certain skull bones compared to their larger relatives, and have (relatively) larger brains. I’ve always been amazed that nearly the same set of organs I have in my body could fit inside a mouse, and these chameleons are taking that comparison to the extreme.

The scientists did a genetic analysis of the new chameleons to check that they are in fact new species, and also examined the differences in their bodies (including their penises – graphic photos in the paper!). They concluded that these new species have evolved to be different because, unsurprisingly, they don’t tend to move very far from their tiny habitats. This lack of movement isolated the populations and over time they diverged and became new species.

There also seems to be a pattern between small body size and small species range in animals from Madagascar – the scientists hope further study of the tiny chameleons and other very small animals (such as frogs) could give more clues as to why this is.

They also suspect that the smallest of the new species, Brookesia micra, could be an example of a ‘double island dwarf effect’ – an island animal that’s evolved to be small, and then been confined to an even smaller island and shrunk even further. So its tiny island home (the brilliantly named Nosy Hara) off the coast of Madagascar could explain why this species can fit on the head of a match.

While I loved reading this paper, it struck some sad notes too. The researchers named two of the four new species Brookesia desperata and Brookesia tristis – desperata meaning ‘desperate’ and tristis meaning ‘sad’ – because of the tragic state of their habitats. As they explain, although the areas where these species are found are in designated nature reserves, in fact their habitats are being destroyed. And for microendemic species confined to small spaces, this is a big problem.

Hopefully a ‘fun’ news story about amazingly small chameleons will inspire more people to take an interest in these beautiful, fascinating animals, and the many undiscovered species that are waiting for their own fifteen minutes of fame. There’s nothing quite so sad as the thought of other equally incredible creatures that we’re destroying before we even realise they exist.

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