New Frog Found—Has "Striking" Color Change

New Frog Found—Has “Striking” Color Change
Color-changing frog Oreophryne ezra is shown in two photographs: at top, the juvenile is black with yellow spots; at bottom, the adult is peach-colored with green eyes.

The color-changing frog Oreophryne ezra as a polka-dotted youngster (top) and as a peachy adult.

Photographs by Fred Kraus, courtesy and copyright ASIH

Christine Dell’Amore

National Geographic News

Published March 10, 2010

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.

(See a picture of another color-changing frog species found last August.)

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.

Color-Changing Frog Threatened by Warming

But Kraus may have to hurry up—even fear of spirits can’t protect the frogs and their extremely small home against global climate change.

(Related: “Cloud Forests Fading in the Mist, Their Treasures Little Known.”)

For one, cloud forests—which require cool temperatures to thrive—may dry up as the planet warms. Cold-averse lowland plants may also start to creep uphill and displace mountain-dwelling species.

“If this happens on a mountain where you only have 650 feet [200 meters] to play with, which is nothing,” Kraus said, “you could easily lose your cloud forest”—along with the creatures that thrive within, including the color-changing frog.


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