Uploaded January 2024 | Updated September 2026, 1 week ago
Researchers have spotted an “extremely rare” green honeycreeper in Colombia that’s half female and half male. The bird’s plumage is divided directly down the middle, with blue feathers typical of males on its right side and the emerald-green feathers of females on its left. This individual is only the second of the species ever recorded exhibiting this trait—called bilateral gynandromorphism—and the first in more than 100 years.
“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,” Hamish Spencer, a zoologist at the University of Otago in New Zealand who witnessed the bird while on vacation, says in a statement. “It is very striking. I was very privileged to see it.”
Bilateral gynandromorphism occurs in a variety of species—including spiders, butterflies, crustaceans and lizards—though it’s never been recorded in humans. In humans, biological sex is usually determined by our chromosomes. Those born female typically have two X chromosomes, while those born male tend to have an X and a Y chromosome. Birds are the opposite. Their chromosomes are designated as Z and W—females have a Z and a W, while males have two Z chromosomes.
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.
Extremely Rare 'Half-Female, Half-Male' Bird Captured On Camera In Colombia
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.
Researchers have spotted an “extremely rare” green honeycreeper in Colombia that’s half female and half male. The bird’s plumage is divided directly down the middle, with blue feathers typical of males on its right side and the emerald-green feathers of females on its left. This individual is only the second of the species ever recorded exhibiting this trait—called bilateral gynandromorphism—and the first in more than 100 years.
“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,” Hamish Spencer, a zoologist at the University of Otago in New Zealand who witnessed the bird while on vacation, says in a statement. “It is very striking. I was very privileged to see it.”
Bilateral gynandromorphism occurs in a variety of species—including spiders, butterflies, crustaceans and lizards—though it’s never been recorded in humans. In humans, biological sex is usually determined by our chromosomes. Those born female typically have two X chromosomes, while those born male tend to have an X and a Y chromosome. Birds are the opposite. Their chromosomes are designated as Z and W—females have a Z and a W, while males have two Z chromosomes.
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.
Extremely Rare 'Half-Female, Half-Male' Bird Captured On Camera In Colombia
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.
