In an extraordinary and exceptionally rare sighting, a bird displaying a remarkable trait known as bilateral gynandromorphism has been captured on camera in Colombia. The bird, identified as a green honeycreeper, exhibits distinctly male colours on one half of its body and female plumage on the other. This phenomenon, documented only once before in the same species over a century ago, has fascinated researchers and bird enthusiasts alike.What is unique about this birdThe half-female, half-male green honeycreeper features vibrant aqua-blue feathers on one side and yellow-green plumage on the other, with a clear and distinct boundary between the two halves. This striking appearance stands in contrast to the typical male green honeycreepers, characterised by bright blue feathers and a black head, or the uniformly green females.A University of Otago zoologist and an amateur ornithologist found a rare case of gynandromorphism in a a wild Green Honeycreeper.pic.twitter.com/JsbJhnfhwWWhat does that mean The bird has a distinct half green, or female, and half blue, male, plumage.This is basically an…— Massimo (@Rainmaker1973) January 4, 2024Is this a rare sighting Who discovered itThe exceptional bird was first spotted by amateur ornithologist John Murillo and later identified by Professor Hamish Spencer, a zoologist at the University of Otago. This rare instance of bilateral gynandromorphism is considered an extraordinary scientific discovery, with only one previous record of such a phenomenon in the same species more than a century ago.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, remarked Professor Hamish Spencer.More about Bilateral GynandromorphismBilateral gynandromorphism, characterised by the combination of male and female traits on opposite sides of the body, indicates a unique error during female cell division when producing an egg. This is followed by double-fertilisation by two sperm. The internal organs of the bird are also likely divided down the middle into male and female components, adding another layer of biological intrigue.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, explained Spencer.What was the researchResearchers had the rare opportunity to study this exceptional bird for 21 months. The green honeycreeper returned regularly to feed on fresh fruit and sugar water provided by the owners of a small farm in a nature reserve near Manizales, Colombia. The findings, including insights into the birds behaviour and potential implications for reproduction, 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,” the researchers noted.This unique discovery not only contributes to our understanding of avian biology but also highlights the awe-inspiring diversity and complexity present in the natural world.
