Rare half-male, half-female songbird has scientists ‘so excited’

by Hannah Frishberg, New York Post, October 23, 2020

https://nypost.com/2020/10/23/rare-half-male-half-female-songbird-has-scientists-so-excited/

A rose-breasted Grosbeak gynandromorph. Annie Lindsay

This songbird can warble both the male and the female parts.

In late September, researchers at the Carnegie Museum of Natural History’s Powdermill Nature Reserve caught and banded a Rose-breasted Grosbeak, not a strange occurrence for Rector, Pennsylvania — except that this particular Grosbeak was a gynandromorph, meaning it had both male and female parts.

“Everyone here, I mean the whole crew, was just so excited,” Annie Lindsay, the nature reserve’s bird banding program manager, told CNN. “There was this scientific interest, of course. But also happiness for seeing something that was so rare.”

Rose-breasted Grosbeaks are “sexually dimorphic,” the reserve explained in a press release, meaning the males and females can be differentiated by their feather colors. “In its 64 years of bird banding, Powdermill’s Avian Research Center has recorded fewer than 10 bilateral gynandromorphs.”

Males have pink wing pits and breast spots and black wing feathers while females have yellow wing pits and brown wing feathers — but this particular bird has both. As well, it is perfectly divided between the two gendered markings, with female coloring on its left side and male coloring on its right.

Discovering such a rarity, in addition to offering scientific insight, also brought the researchers a huge morale boost.

“The entire banding team [is] riding the high of this once-in-a-lifetime experience,” said Lindsay. “One of them described it as ‘seeing a unicorn’ and another described the adrenaline rush of seeing something so remarkable. They all are incredibly grateful to be part of such a noteworthy and interesting banding record.”

Half-Male, Half-Female Songbird Discovered, Live Science, October 21, 2020

Bird hermaphroditism, or bilateral gynandromorphism is “very uncommon,” but normal, Lindsay continued, and for big-time bird fans like those at Powdermill seeing it in person is a great gift.

While a natural occurrence, having the genitalia of both genders does pose questions about the bird’s ability to reproduce.

Usually, only a female bird’s left ovary is functional, and since this bird’s left side is female, researchers believe it may be capable of breeding. “The bird’s ability to reproduce could also depend on whether it sings like a male,” the researchers add, “which would potentially attract females and elicit a territorial response from other males.”