It’s no Godzilla, but an earless rabbit allegedly born near Japan’s severely-damaged Fukushima Dai-ichi nuclear plant has become the latest poster child for the side-effects of radiation exposure.
The bunny — purportedly captured on video just outside the crippled plant exclusion area and posted on YouTube on May 21 — has become big news in Japan and, to a lesser extent, elsewhere, stoking fears that contamination from the damaged facility could cause genetic mutations.
Though the long term environmental effects remain unclear, there’s no denying that the radiation emitting from Fukushima Dai-ichi, about 140 miles northeast of Tokyo, poses a major health risk.
However it’s hard to say whether this earless bunny’s strange appearance can be blamed on radiation, according to F. Ward Whicker, professor emeritus at Colorado State University’s Department of Environmental and Radiological Health Sciences.
“Yes, radiation can cause mutations that can be occasionally expressed as obvious birth defects, such as shown in the video,” Whicker wrote in an e-mail. “However, to say this is the result of contamination from the Fukushima accident is a stretch, because natural radiation, as well as many other chemical substances in the environment and other factors, can also be mutagenic.”
In most cases, the cause of congenital birth defects in humans and other animals cannot be determined, he said.
“So far as science has shown, there have never been mutations produced by ionizing radiations that do not occur spontaneously as well.”
News reports from around the world have cast the bunny as a “nuclear rabbit” or a “mutant rabbit,” citing the fact the animal and was born and raised on “possibly contaminated” outdoor grass in the Fukushima prefecture’s Namie City.
But nuclear historian Richard Rhodes says a link between the earless rabbit and radiation “is highly unlikely.”
The evidence, Rhodes says, can be found in research conducted in the aftermath of the atomic bombings of Hiroshima and Nagasaki.
“In the years after World War II, there was a major American commission that looked into the health ramifications of the atomic bombings, and it found no genetic changes in the populations of Hiroshima or Nagasaki,” said Rhodes, who has written extensively on the bombings. “There were no birth defects attributed to the bombing, and no genetic consequences.”
In fact, the earless rabbit’s strange appearance may not be caused by genetic factors at all.
Far removed from radiation concerns in Japan, Mary Cotter, a licensed veterinary technician and New York City chapter manager for the House Rabbit Society, has had two run-ins with earless rabbits.
“I’ve never encountered a rabbit that is born with no ears, but mother rabbits are assiduous groomers,” Cotter said. “A mother can enthusiastically over-groom and chew off a baby’s ears.”
Maternal over-grooming can leave young rabbits looking like they were born without ears, though close investigation could reveal jagged edges of flesh surrounding their auditory canals.
Cotter believes that was the case for two earless rabbits — fittingly dubbed “Stubs” and “Nubbins” — that she has taken into her care.
With only one video as evidence, it’s impossible to know why the bunny has no ears, said Dana Krempels, a rabbit expert and University of Miami biology professor.
“It is pretty much impossible to say whether this anomaly is due to radiation. But it’s very unlikely, in my opinion, that a failure to develop ears could be due to a single mutation,” said Krempels, who heads the Miami chapter of the House Rabbit Society.
Mutations and epigenetic changes are hard to track, varying greatly between subjects.
“But if more baby bunnies with physical anomalies show up in this area, it’s certainly a red flag,” she said.