The 2200 Pound Lady Birds of Madagascar

Matt Hrodey writes:
A massive but surprisingly dainty “elephant bird” once wandered Madagascar, according to a new study that hands the title of largest-ever bird to a new species. The winner? Aepyornis maximus, which lived more than 1,200 years ago on the island of Madagascar and wielded a raptor-like beak and impressive talons, though it probably ate mostly plants and the occasional small lizard. The largest elephant birds stood about 9 feet tall and weighed up to 2200 pounds, about as much as a small car or rhinoceros, according to the size of their eggs. They would have loomed over all other humans and animals on the island, including the early Polynesians who arrived there some 2,000 years ago. 

Winner by a Beak Previously, the title of largest-ever bird belonged to another elephant bird species, Vorombe titan, which won the honor thanks to a 2018 study that analyzed elephant bird bones from around the world. The new study released in 2023, which relied on DNA extracted from ancient elephant bird eggshells, concludes that the V. titan and A. maximus material differed so little that it best formed a single species related to modern-day ostriches, emus and kiwis. Further, the researchers suggested that V. titan may actually be the female members of A. maximus, in an arrangement similar to kiwi populations, where the females are up to twice as large as the males. 

Researchers spent several years collecting 950 shells from island sites, some of which they first identified from satellite imagery, in an attempt to supplement the sparse skeletal record of the birds. Wet conditions had worn away at the bones’ DNA and left researchers little to work with. In the end, they opted to streamline the elephant bird family, which had once extended to 16 species, to a scant three. “These findings are an important step forward in understanding the complex history of these enigmatic birds,” says Alicia Grealy, who conducted this research for her doctoral thesis at Curtin University in Australia, in a press release. “There’s surprisingly a lot to discover from eggshell.” Jigsaw Puzzle She partnered with Gifford Miller, professor of geological sciences at the University of Colorado Boulder, who had long studied eggshell remains in Australia and elsewhere around the world. They started out egg-collecting in the dry southern reaches of the island and then moved to the swampy, forested northern, where they found an unexpected new genetic lineage of A. Maximus. The shells contained mitochondrial DNA sealed in so tight the team estimated it could have survived intact for 10,000 years. That doesn’t mean it was fully intact: Once the scientists had extracted the genetic information, they still had to piece together the disparate segments like a “genetic jigsaw puzzle” to arrive at genomes to study. As is the case with other megafauna, elephant birds disappeared as Homo sapiens proliferated across the globe, and no one is sure exactly why. “What is it that early humans are doing that's resulting in extinction of big animals, especially?” says Miller in a press release. “This is a debate that's been going on for my whole life.”