Wellington Zoo's female Himalayan Monal, Patrick, is starting to develop male features, this happens once the bird passes breeding age. Video / Mark Mitchell
A female bird at Wellington Zoo is starting to grow feathers usually seen on males as part of a process known informally as “henopause”.
Patrick the Himalayan monal came to the zoo in 2015 from a private breeder, and is now about 8 and a half years old.
Despite being female, she was named Patrick because it is difficult to differentiate female and male Himalayan monal chicks from each other.
The only ways to determine sex is to wait until the chicks reach maturity and develop different plumage, or to do a DNA test, zookeeper Ashleigh Vinicombe said.
Vinicombe said Patrick stopped laying eggs a few years ago and was considered “geriatric”. She has recently started growing plumage normally seen on male monals.
Patrick has been growing her new plumage over the past couple of months. Photo / Mark Mitchell
“Her ovaries are probably starting to become a bit more dormant . . . basically without the prevalence of that estrogen hormone she’s reverting back to the male-type feathers and plumage. She’s starting to grow beautiful rainbow, metallic feathers,”Vinicombe said.
It is not known whether this process happens to every monal upon ageing, as not all birds in the wild live as long as those in zoos. It has been seen in other birds but this is the first time it has been witnessed at Wellington Zoo.
Vinicombe was not aware of any official term for the process, but said it was known informally sometimes as “henopause”, particularly as it has been witnessed happening with domestic chickens.
Wellington Zoo staff posted photos on Facebook of Patrick’s transformation, saying she started growing the male plumage a couple of months ago.
“Research shows that when a female bird gets past the prime age for breeding, they start to lose estrogen and develop male bird characteristics,” the Facebook post said.
“We are thrilled to be able to share this unique moment with all of our visitors and to raise awareness about the diversity of animal behaviour and biology. We hope this story inspires you to celebrate diversity in all forms and to show love and compassion to all creatures, great and small.”
