Posted on 09/10/2003 3:39:39 PM PDT by blam
Bones of giant birds pose mating mystery
By Steve Connor
11 September 2003
A study of the fossilised bones of a giant bird which died out about 800 years ago has revealed that the female was three times the size of the male.
Scientists discovered that the largest giant moa birds were not a separate species, as originally thought, but an extreme example of sexual dimorphism. A study of the DNA extracted from the bones of large and small moas revealed that the females were huge, weighing up to 250kg and standing up to three metres tall. The males were puny, weighing as little as 60kg, and were about one metre tall.
This raises the question of how the moa cocks were able to mate with their huge hens.
Professor Alan Cooper, director of Oxford University's Ancient Biomolecules Centre, said the findings were unexpected because it was widely thought that large, small and medium-sized moa belonged to separate species that did not interbreed.
He said: "Such a large difference between the sexes has never been seen before, and consequently nobody considered that these different groups of bones could actually belong to the same species. It raises concerns about the logistics of mating - but in the emu for example, the female sits during mating. If this was the case with the moa, it would have looked like a horse and jockey."
The study, published today in the journal Nature, analysed DNA extracted from the bones of moa that lived in swamps and caves in New Zealand. Moa died out after the arrival of the Maori, around AD1100, who hunted the birds to extinction.
Professor Cooper said: "When we examined genes that evolve very rapidly we could find no consistent differences between tiny and giant [moa] specimens. When we looked at sex-linked genes all the medium and giant individuals showed up as femaleswhile the males were the little ones."
It is the first time that scientists have identified the sex of an extinct animal using DNA.
The scientists noted that the male and female birds weighed approximately the same until they got married.
Bada bing!
Scientists could look to Oprah Winfrey and the supposed boyfriend Stedman Graham for an answer.
Very carefully, i assume.
Yes, they were killed off by a meteor swarm in 1178AD.
Well, birds don't have penises - the story of Leda and Zeus in the form of a swan was pretty good, but Hera ain't buying it (lipstick on the toga, you know) - so what they do is rub their cloaca together and transfer the, er, genetic material that way. You can see all the boy birds in the bars of a Saturday evening - "Hey, Tweety! Let's go out and git ourselves a little cloaca!" - but difficulties in mating in such a case of dimorphism won't be as insuperable as one might think.
It does remind me a little of the fabled Oooah bird. Cubical eggs with sharp edges. You can hear them in the jungles when the sun goes down, "Ooooooooooooahhhhhhh!"
,,, what a coincidence - so did the Morioris.
Well,if it comes to a toss-up between scientists knowing how they did it, and the males knowing how, it is better that the males knew how...
The Maori said they didn't kill off the Moa.
"A number of observations suggest that catastrophic cometary or meteoritic impacts around the same time also affected the Pacific basin: Maori legends of great fires destroying forests and the moa bird, to be associated to the recently found Tapanui craters"
Evidence Of Tunguska Type Impacts In The Pacific Basin Around 1178AD
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