Deciphered Bush Moa genome provides insights into New Zealand’s extinct avian world

A team of evolutionary biologists has reconstructed the nearly complete genome of the bush moa (Anomalopteryx didiformis), a flightless bird from New Zealand that went extinct 500 to 600 years ago. Researchers from Harvard University, East Carolina University, Osaka University, and the University of Toronto sequenced ancient DNA from a fossil bone found on the South Island to decode the bush moa genome.

The bush moa was one of about nine moa species that once inhabited the two main islands of New Zealand. Moas were among the largest flightless birds globally but became extinct between the late 13th and early 16th centuries when Polynesians settled in New Zealand. The main causes of their extinction were intense hunting and the introduction of non-native species such as dogs. Natural predators of moas included the Haast’s eagle and the Eyles’s harrier (Circus teauteensis), which are also extinct today.

The bush moa was a relatively small moa species, slightly larger than a turkey. In comparison, female South Island giant moas reached a height of up to two meters, while females of the North Island giant moas were almost the same size. Male moas were significantly smaller.

The absence of wings in moas: Genome solves genetic puzzle

In 2018, researchers from Harvard University published study results reconstructing the nuclear genome of the bush moa. This partial sequencing of the genome revealed that the genetic blueprint for wing formation in moas fundamentally worked but that the genetic instructions signaling when, where, and how much wing to form were faulty. It is likely that the wing development genes mutated over time as moas gradually became flightless land dwellers. Moas are unique in the bird world in that, unlike other flightless birds that have at least rudimentary wing bones, they had no wings at all.

Bush Moa genome reveals surprising bird abilities

The current study, published in Science Advances, provides a more detailed analysis of the genome of the extinct bush moa. The research team describes its findings as the restoration of a complete mitochondrial genome as well as the core genome of a male moa. This new investigation also confirms previous findings regarding wing formation.

After sequencing, the researchers discovered that the birds were able to see in the ultraviolet spectrum – a capability that would have helped them find hidden food. Additionally, it was found that moas reacted sensitively to bitter foods – a characteristic common in modern birds. The data also suggest that the probable population of these birds once numbered up to 240,000 individuals and that the birds split from their closest relatives about 70 million years ago.

Reconstructing the genome of long-extinct species like the bush moa poses a challenge due to the often limited amount of available ancient DNA. The new study opens up further possibilities for future research, as the reconstructed genome provides a valuable resource for conducting in-depth studies on the evolution of birds and their morphological divergence.