Rare half female, half male bird spotted by University of Otago zoologist | Hacker News Reader

Rare half female, half male bird spotted by University of Otago zoologist

otago.ac.nz

118 pointsclouddrover60 comments

There was also a Cardinal like this in Pennsylvania a couple of years ago - https://www.bbc.com/news/world-us-canada-56189600

To me, the bilateralness is the super cool part. I imagine that this happens more often, but you just don't notice from a visual inspection.

There are multiple possible causes, but one is a phenomenon known as genetic mosaicism. That is when an organism is made up of multiple distinct genetic lineages, in species where this isn't typical. It can occur from things like twins merging in the womb, or from a stem cell in the embryo mutating and all its descendants being a little different. In humans (or birds) it often shows up in stripes (related to the basic developmental segments of the vertebrate animals) or indeed, bilateral. For a rather visible example: it is sometimes the cause of heterochromatic (different colour) eyes.

And sometimes it can result in DNA test results showing that children are not related to their mother, if when you swab the mother you don't get the same lineage as the one that developed into her ovaries:

https://embryo.asu.edu/pages/case-lydia-fairchild-and-her-ch...

> captured on film

The article makes no further mentions of actual film, so presumably the phrase now also applies to digital photography?!

Yep; English tends to hold onto these archaic references. People also still talk about getting things on tape etc.

Back when things were on tape they would still call it film.

When I listen to an audiobook on my phone it feels natural to say I'm listening to the book on tape.

We’ll also still dial a phone number despite dials being gone for a half-century.

We see this sort of thing in computer icons, too. People who have never seen a real floppy but recognize it as a "save" icon. It's kind of neat how this evolves.

Same way you still dial a phone or roll up a window.

The window is still going up via the same rolling mechanism there's just a motor doing it. Source I replaced my window motor and regulator this month

but windows cannot be rolled up... they could be cranked up, or pushed up, or slid up, but they're not pliable enough to be rolled up.

There's a term for that: linguistic skeuomorph. With a stylus on a tablet was how the ancient Romans and Sumerians wrote. That imagery and history is evoked when those words are used to refer to portable computers. They were chosen by analogy with historical understanding. It's like when you pattern the plastic tiles to make the floor look stone or wood. There are iconographic skeuomorphs too, like when someone born in the 21st century taps a floppy disk icon on their computer to copy data, when they have never seen a physical floppy disk.

Chimerism is a whole lot of fun. Realistically, there are loads of humans with portions of their body differing pretty significantly in genes just due to somatic cell mutations during early development (not just standard zygote-fusing), right?

Sure, most of these changes would still be nearly imperceptible, but maybe some day whole-genome sequencing will be cheap enough that the true frequency of mosaicism can be studied by yoinking cells from all over one's body.

In the mean time, the intentional 'chimerization' of plants via grafting is pretty interesting too. Adam's Laburnum is a very visually striking example somewhat akin to this bird, https://en.wikipedia.org/wiki/%2B_Laburnocytisus_%27Adamii%2... sporting both yellow and coral-pink flowers, though the bilateral nature of the bird's mosaicism is what's really special.

It has good news and bad news https://youtu.be/4LVi-oNWgc8?feature=shared

I thought they meant hermaphrodite but then saw the picture. They mean luterally half, right down the middle.

It seems like a lot of people want to jump in and start making political points, before taking time to read the article.

> I thought they meant hermaphrodite

The case in the article is gynandromorphism. Intersex is not necessarily a form of gynandromorphism.

Intersex refers to individuals who have biological characteristics that don't fit neatly into the two biological sexes of male and female. This can include variations in chromosomes, gonads, hormones, or genitals.

Gynandromorphism is a specific type of chimera, where the individual has both male and female tissues distributed in a mosaic pattern. This typically happens due to an error during early embryonic development. Occurs mainly in species of animals with strong sexual dimorphism.

In some cases, intersex individuals might have features resembling gynandromorphism, but usually it is more subtle variation in sex characteristics rather than a mosaic pattern of male and female traits.

>Occurs mainly in species of animals with strong sexual dimorphism

Occurs or is noticed?

I’ll just quote Wikipedia directly:

“Gynandromorphism has been noted in Lepidoptera (butterflies and moths) since the 1700s.[1][2][3] It has also been observed in crustaceans, such as lobsters and crabs, in spiders,[4] ticks,[5] flies,[6] locusts,[7] crickets,[8] dragonflies,[9] ants,[10][11] termites,[12] bees,[13] lizards,[14] snakes,[15] rodents,[16][17] and birds.[18][19][20][21][22] It is generally rare but reporting depends on ease of detecting it (whether a species is strongly sexually dimorphic) and how well-studied a region or organism is. For example, up until 2023 gynandromorphism had been reported in more than 40 bird species, but the vast majority of these are from the Palearctic and Nearctic, indicating that it likely is underreported in parts of the world that are not as biologically well-studied.”

I'm not sure why you're trying to tell me about intersex. I was talking about hermaphroditism like in earthworms and snails.

Cool looking bird

Mother nature's a maaaaad scientist, Jerry!

This is really cool, I think I found my lunchtime rabbit hole to read more about.

Which we can all agree is both cool and a biological anomaly… much like it can happen in humans.

You should probably read the article first, before jumping into politics:

“This particular example of bilateral gynandromorphy – male one side and female 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,” he explains.

I'm not sure if it could happen in humans, but apparently it has never been observed. This phenomena is called bilateral gynandromorphism and is where the entire body shows both male and female traits (along a bilateral split). You're probably thinking of hermaphrodites (e.g. she-males) which is where the animal only has reproductive organs of both sexes.

Chimerism exists in humans as well, and likely gynandromorphism as well. I don't think this bilateral version has ever been seen, but more subtle forms may be more common than assumed - it can only really be discovered through genetic testing of different parts of the body.

It can, and does, I used to know a bilateral chimera, you could clearly tell which side was which by hair colour, she identified as female.

Btw, 'she-male' a) does not refer to hermaphrodites, b) is an offensive term, and has been considered offensive for around 30 years, so no 'modern wokism' retort required.

No offense intended by "she-male" - it's used in the porn industry where it's presumably meant to attract a certain audience rather than be offensive. I didn't realize that these are (always? usually?) trans women.

The term "shemale" is usually confined to porn, where it refers to transgender women who still have their penis, rather than anything related to hermaphrodites.

Thanks - I didn't realize!

Sciam on chimerism: https://www.scientificamerican.com/article/3-human-chimeras-... ; although not bilateral.

I don't think there's any known example of bilateral chimerism in humans? Hermaphroditism is humans (and for that matter, in birds; the above is a really unusual case) works completely differently.

Perhaps not such a stunning bilateral one, but two-sex chimerism definitely is: https://en.wikipedia.org/wiki/Human_chimera

And I can really only say "perhaps". Humans have often hidden or killed their abnormalities for much of history, and birds significantly outnumber us.

(edit: there's a semi-recent example of noticable partial bilateral human chimerism actually: https://www.deccanchronicle.com/lifestyle/health-and-wellbei... Seems like largely a numbers game to me.)

Human chimera exist: https://en.wikipedia.org/wiki/Human_chimera

The real question is what is a "Sesquicentennial Distinguished Professor"?

From what I can gather, it's a special title at the University of Otago. It means he was received the standard title of Distinguished Professor [0] as part of a special group of appointments made to celebrate the university's 150th anniversary in 2019. [1]

0: https://en.wikipedia.org/wiki/Distinguished_professor 1: https://www.otago.ac.nz/otagobulletin/news/poutoko-taiea-dis...

half female, half male phenotype.

That makes it sound like it's highly technical and uninteresting - on a completely layman level even it's pretty fascinating, there's a photo, it's split right down the middle with one colour (each apparently as would be expected from the male or female bird) each side!

> “The phenomenon arises from an error during female cell division to produce an egg, followed by double-fertilization by two sperm,” he explains.

The bird is a chimera, with a different genome on each side of its body, one male (ZZ), one female (ZW).

... and they determined that from a photo?

It's not the first bilateral gynandromorph bird found, though it.may be the first for this species.

I mean... we know how biology works? So...

It's less difficult than you think. Tetragametic chimeras for half-sider budgerigars have different genomes on either side, and the mechanism they occur by is through fusion of two distinct embryos with different DNA[1]

Given we know the phenotype of this Green Honeycreeper has a male half and a female half, and given how incredibly likely that the mechanism is following established ways that chimeras occur, it is not hard to say with confidence that the male and female halves of the observed bird are almost certain to have distinct genotypes. Put another way, it would be a much more radical hypothesis that "this halfsider bird with two distinct sexes would not be a chimera."

Obviously we'd ideally wish to collect DNA samples from each side of the bird

[1] https://en.wikipedia.org/wiki/Half-sider_budgerigar

The interesting part to me is that it's described -- in birds -- as an error in female cell division, rather than the fusion of two embryos.

That implies that there are no same-sex chimera birds running around undetected.

Chimera is normally an organism formed by two normally fertilized fetuses fusing together. They've made goat/sheep chimerae, crazy stuff.

caused by a half male and half female.... conplete it with me...

...photograph? ...parent? ...avian agenda?

I'm at a loss

I'm pretty sure the GP was looking for "genotype", but "avian agenda" wins Phrase of the Day award. I hereby present you with the lovingly artisanally hand-typed period at the end of this sentence.

It sounds like it's a chimera, so there's actually a half male half female genotype (or rather, a full male genotype in half the body and a full female genotype in the other part).

What happens when it wants to mate?

Mitosis

meow meow meow meow XDD

Bilateral gynandromorphs tend to be infertile.

https://www.livescience.com/64831-cardinal-gynandromorph.htm...

I was more wondering about their behavior, like do they try to seek out mates? Are they attractive to non-gynandromorph birds? Do they physically attempt intercourse?

> but this one may actually be fertile as the left side is female, and only the left ovary in birds is functional

It's really fascinating!

Won't somebody please think of the gametes?

Not in SF?

What are their pronouns?

Shhh no on tell the GOP

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