Poisonous Frogs are More Fit

After testing hundreds of frogs representing dozens of species on an amphibian version of a treadmill, researchers have determined that colorful, highly poisonous frogs have the greatest aerobic capacities.

Earlier studies had suggested a link between poison and metabolism in frogs, but involved just a handful species.

In frogs, especially bright colors generally signify toxicity, informing predators of their prospective meal’s unpalatability. But whereas most poisonous animals produce venom naturally, the frogs distill it from their food.

To find the right insects, they forage far and wide, rather than waiting for whatever fare passes by. Evolution would seem to have produced aerobic adaptations that help poisonous frogs roam, then amplified coloration as a defensive signal.

It’s also possible that bright coloration evolved first, providing some sort of advantage — predator defense, perhaps, or help finding mates — that allowed those frogs to range farther than their drab brethren. That in turn could have allowed them to specialize in eating uncommon, toxin-enabling insects.

Read more in the original article here.