The fanciful colored markings of poison dart frogs are a warning to predators: If you eat me, you’ll regret it.

These tiny, colorful creatures secrete bitter toxins in their skin, and birds have come to associate their distinctive markings with danger. The frogs’ chemical defenses can cause swelling, paralysis and sometimes even death. Their markings are so distinctive that it seems any frog trying out a new look would be running a serious risk.

And yet, new markings do crop up. Dyeing poison dart frogs in one part of French Guiana usually are blue and black with yellow markings. But in the nearby Mont Grand Matoury nature preserve, they have white stripes. Scientists curious about how this alternative coloration was working out ran a series of experiments, and reported some surprising results last week in Proceedings of the National Academy of Science.

The white-striped frogs were not as effective at scaring off predators as their yellow brethren, they found. But they still managed to avoid being outcompeted by the fitter, more threatening yellow-striped frogs, perhaps in part because of their location.