Color Changing Frog

A newfound frog species undergoes a "striking" change from a black, yellow-spotted youngster to a peach-colored, blue-eyed adult, scientists say.

Oreophryne ezra was discovered in 2004 in a tiny, mountaintop cloud forest in southeastern Papua New Guinea. The forest has been long avoided by locals, who believe the misty jungle to be taboo, and perhaps guarded by spirits.

Though a few other frogs are known to switch colors as they mature, "I don't think the difference in color pattern is as startling as what's seen in this species," said Fred Kraus, a vertebrate zoologist at the Bishop Museum in Honolulu, Hawaii.

But why the amphibian undergoes such a drastic transition is far from black and white, added Kraus, leader of a new study on the frog in the December 2009 issue of the journal Copeia.

The juveniles look like poison dart frogs, so "the first thing that comes to mind is 'warning,'" Kraus said. The young frogs even sit on leaves in broad daylight, consistent with the "danger doesn't bother me" audacity of poisonous frogs, he added.

But "if the juvenile has a warning color, why would adults lose it? It makes no sense at all."

To solve at least part of the riddle, Kraus would like to test whether the young frogs have poison to back up their bluster.