North America

A broadcast on french TV tonight [Jan, 2000], sort of National Geographic stuff as you know it. They stated that about 10% of the supposedly black bears in Canada are now being born white, for an unknown reason.

Offered by Veronique.

Colorless in a World of Color
By Peter Friederici, National Wildlife Magazine, Aug./Sept. 2000

Prairie dogs
Last summer in west-central Wyoming, Dick Baldes saw something extraordinary. A resident of the expansive Wind River Indian Reservation, he was accustomed to seeing white-tailed prairie dogs, which range in the area’s shortgrass prairies. But he had never seen prairie dogs like these: about a dozen snow white, pink-eyed individuals scattered amid the hundreds of ordinary, earth-colored animals. Baldes had worked for year as a biolgist for the U.S. Fish and Wildlife Service and he knew this sighting was rare. So he photographed and videotaped the white creatures for three weeks. Then, seemingly overnight, the animals vanished. It wasn’t too difficult for Baldes to guess why. “From a distance you can’t see the brown prairie dogs, but the white ones stood out like sore thumbs,” he says. “They must have been pretty vulnerable to aerial predators like hawks and eagles.”

Toads
Lack of normal pigmentation has also been seen occasionally en masse in amphibians such as toads and salamanders. Last summer, Oregon biologist Jay Bowerman found thousands of unusually pale individuals in a population of western toad tabpoles. “Approximately 1 percent of the tadpoles appeared to be virtually white,” he says. “They appeared to lack any black or dark pigmentation.” In the Oregon lake where Bowerman studied the creatures, the normal-colored tadpoles continued to develop and completed metamorphosis, while the white tabpoles did not progress beyond the early leg stage. The scientist captured some of the white tadpoles and observed that they remained healthy even though they did not transform into adulthood. He surmises that the phenomenon could have resulted from a genetic mutation that disrupted the production of both hormones and pigments needed for metamorphosis. Eventually, the white tadpoles in the lake disappeared, while those Bowerman kept in an aquarium lived on, leading him to suspect that they were far easier for predators to find than the darker tadpoles.

Chernobyl and albinism (radiation link)
In the Ukraine, where the Chernobyl nuclear plant accident caused large-scale radioactive contamination, barn swallows subsequently showed a much higher rate of partial albinism than other, uncontaminated populations. The rate of partial albinism among swallows near Chernobyl jumped from 0 percent before 1986 to 15 percent in 1991.