Rare half-male, half-female bird captured on film
A zoologist has captured footage of a rare half-female, half-male bird while on holiday in Columbia, after it was spotted by an amateur ornithologist.
The wild green honeycreeper had a distinct and unique plumage which was half green and half blue. Green plumages indicate a female green honeycreeper, and blue plumages usually appear on males.
This means that the bird is a rare example of a bilateral gynandromorph, meaning that one side of it has male characteristics and the other has female.
The green honeycreeper had male plumage on its right side, with female plumage on its left. It was observed to remain in the area for at least 21 months.
Its behaviour appeared to match that of other wild green honeycreepers, although it did wait until the other birds had left before feeding on food left out by the property owners.
The phenomenon is extremely rare in birds, which means that the images captured by Professor Hamish Spencer are particularly significant. It is only the second recorded example of gynandromorphism in a green honeycreeper in more than 100 years.
Bilateral gynandromorphism is usually identified in species with strong sexual dimorphism, including butterflies, crustaceans, lizards and rodents.
It occurs when an error during female cell division for producing an egg is followed by double-fertilisation by two sperm.
The images of the bird, which Prof Spencer called "arguably the best of a wild bilateral gynandromorphic bird of any species ever", have supported a report on the findings. It has contributed to scientists’ understanding of the phenomenon, including the discovery that female plumage was possible on either side.
Prof Spencer, from the Department of Zoology at the University of Otago, said: "Many birdwatchers could go their whole lives and not see a bilateral gynandromorph in any species of bird. The phenomenon is extremely rare in birds, I know of no examples from New Zealand ever.
"It is very striking, I was very privileged to see it,"
The new study is published in the Journal of Field Ornithology.
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