Blind but perfectly healthy kiwis have been found living in New Zealand, New Scientist reports.
Researchers think the flightless nocturnal birds may be evolving to lose their eyesight altogether. They found that the blind kiwis seem to survive just as well using other senses such as touch, smell and hearing. Maintaining good eyesight, they say, might be a waste of energy.
A research team found the blind birds during a study of 160 Okarito brown kiwis on New Zealand’s South Island.
“We found a very high prevalence of birds with eye lesions,” Alan Tennyson, of the Museum of New Zealand Te Papa Tongarewa in Wellington, told New Scientist. “A third of them had eye problems.”
“No other birds are known to have a free-living population of blind [individuals],” Tennyson said, "But plenty of other animals, such as moles and cave-dwelling fish, have evolved blindness.“
"The finding of completely blind birds in good physical condition was absolutely stunning,” said team member Christopher Murphy of the University of California, Davis.
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