Researchers have discovered a nearly intact dwarf mule egg, a bird that went extinct on a remote island near Australia nearly 200 years ago, according to a recently published study.
The research, published in a journal Biology Letters, notes that the ‘unique’ egg was found near a sand dune on King Island.
The egg was found in fragments and parts of it eroded, the study added.
Scientifically known as Dromaius novaehollandiae minor, the extinct emu King Island is considerably smaller than the emu of mainland Australia, known as Dromaius novaehollandiae.
Although the extinct emu is much smaller than the traditional emus, the egg is about the same size.
The researchers found that mainland emu eggs are 1.3 lbs, while the King Island emu egg was 547 grams or 1.2 lbs, just slightly smaller than the mainland emu despite the huge difference in body size.
The study’s lead author, National History Museum of London paleontologist and research associate Julian Hume told Live Science this may be because the young had to be large enough to retain body heat and find food shortly after birth.
‘Our study found that dwarf mice had a similar breeding strategy to the mainland emu, including large clutch size, synchronized hatching of hatchlings to counter predator effects, and thermos-regulation in hatchlings to provide warmth,’ the researchers wrote in the study.
Only in the islands of southern Australia did the limited resources result in rapid discoloration and the retention of a large egg. This scenario provides an interesting evolutionary answer to island size, insular population and morphological plasticity in dwarf mice and merits further investigation. ‘
Sadly, King Island’s dwarf moan died out in 1822, just a few years after the people arrived on the island, making it difficult for experts to learn about them.
“Because they are extinct completely and rapidly, the true magnitude of these adaptations to a rapidly changing environment due to fluctuating sea levels is now impossible to determine,” the researchers added in their study.
An artist’s illustration of pygmy and elephant seals on King Island. Dwarf goose became extinct in 1822
(Left to right) A mainland emu egg, a Tasmanian emu egg, and a Kangaroo island emu egg
The King Island emu egg (pictured) was about the same size as the mainland emu egg, despite the size of the two birds being drastically different
Emus on the mainland exist all over Australia, while the emus from King Island, Tasmanian and Kangaroo Island became their own distinct species, becoming separated and isolated after the end of the last Ice Age.
A regression analysis table comparing dwarf egg size size to mainland emu
There were dwarfs in Tasmania, Kangaroo and King Islands, all of which are now extinct.
Each emu was its own kind (D. n. diemenensis for Tasmanian emu and D. n. baudinian for Kangaroo emu) all of which varied in size, although the King Island was the smallest.
About 34 inches tall, some King Island emus could grow to nearly five feet long and weigh between 45 and 50 pounds, experts previously said.
Mainland emus are the second largest living birds, behind only the ostrich. They can grow to nearly six feet in length and weigh between 79 and 88 pounds.
After the last Ice Age, when sea levels rose, the three islands separated and the emus continued to evolve on their own, eventually making King Island the smallest before completely disappearing.
Nonetheless, Hume was ecstatic when his study co-author Christian Robertson found the egg.
“He found all the broken pieces in one place, so he painstakingly glued them back together and had this beautiful, almost complete emu egg,” Hume told Live Science. “The only one known in the world [from the King Island dwarf emu]When Robertson invited Hume to study it with him, Hume said, “ Yes, please. ‘
As the King Island dwarf moan kept shrinking after isolation, it’s likely that larger eggs would have benefited, Hume told Live Science, similar to the modern day kiwi in New Zealand.