The details of the findings have been published in the Journal of Field Ornithology.
An ''extremely rare'' half-female, half-male bird has been caught on camera, a sighting that has only been reported once previously in this species more than 100 years ago. According to the Independent, the rare bird has male colours on one half of its body and female plumage on the other half. This bird is only the second of the species ever recorded exhibiting this trait called bilateral gynandromorphism.
Notably, a team of researchers stumbled upon the remarkable scientific discovery on a small farm in a nature reserve near Manizales, Colombia. Amateur ornithologist John Murillo who was part of the research team was the first one to spot the unusual creature, identified as green honeycreeper bird. He pointed out the bird to Professor Hamish Spencer, who is a zoologist at the University of Otago.
The bird has aqua-blue feathers on one half and yellow-green plumage on the other with a clear boundary in the middle. This is in stark contrast with typical male green honeycreepers that have bright blue feathers with a black head or females that are green all over.
''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,'' Hamish Spencer said in a statement.
Its internal organs were also likely divided down the middle into male and female, as per the researchers.
''This particular example of bilateral gynandromorphy – male on one side and female on the other – shows that, as in several other species, either side of the bird can be male or female. The phenomenon arises from an error during female cell division to produce an egg, followed by double-fertilization by two sperm,'' Mr Spencer explained.
They studied the rare bird for 21 months as it returned to feed on the fresh fruit and sugar water left out every day by the owners of the Colombian farm.
The details of the findings have been published in the Journal of Field Ornithology.
''In general, it avoided others of its species, and the others also avoided it; it seems unlikely, therefore, that this individual would have had an opportunity to reproduce,” researchers wrote.