This anomaly is attributed to the bird’s early development, involving genetic-level changes leading to the differentiation of cells into both male and female characteristics, resulting in a bilateral gynandromorphic bird. The discovery was made by University of Otago zoologist Professor Hamish Spencer during a holiday in Colombia.
Amateur ornithologist John Morillo spotted the rare Green Honeycreeper, capturing images of its distinct half-green (female) and half-blue (male) plumage. The bird’s rarity is evident as it was photographed for the first time. Both experts managed to capture a glimpse of the bilateral gynandromorph, visually documenting this unusual occurrence.
The bird exhibits female characteristics on one side and male characteristics on the other, scientifically referred to as bilateral gynandromorphism. Consequently, one side has male plumage (feathers), and the other side has female plumage, including corresponding reproductive organs.
Details of the findings have been published in the Journal of Field Ornithology, emphasising the shock that this is the only recorded example of gynandromorphism in the species in over 100 years.
The bird’s unique characteristic is attributed to double fertilization by two sperm cells during the female cell division process. This sheds light on avian sexual behaviour through both male and female characteristics, resulting in gynandromorphs.
This particular bilateral gynandromorph highlights that either side of the bird can become male or female. Understanding avian species and their sexual behaviour is crucial for comprehending their rarity and importance.
It’s essential to note that gynandromorphism differs from hermaphroditism, where an individual possesses both male and female reproductive organs simultaneously.