In the Footsteps of Moas: Where New Zealand’s Flightless Birds Find Refuge

The settlement of the Pacific Islands by humans led to rapid waves of extinction for many animal species, whose dynamics are difficult to reconstruct. Among the affected species were the wingless moas, which were only found in New Zealand. These often massive birds went extinct in the 14th or 15th century after the first Polynesian settlers arrived on the islands.

Today, there are six recognized genera of moas with at least nine different species. These include the North Island giant moa, the South Island giant moa, the crested moa, the bush moa, and the eastern moa. The birds inhabited various environments, from dense forests to open grasslands. Their diversity in size and ecology made them an integral part of New Zealand’s ecosystems.

A study recently published in the journal Nature Ecology & Evolution investigates the distribution and extinction dynamics of six genetically distinct moa species in New Zealand. The international research team, led by scientists from the University of Adelaide, used detailed simulations that accounted for the interactions between climate, humans, and moas. These simulations were compared with extensive fossil records for validation.

Reconstructing the moa’s past to protect endangered birds

The results show that despite significant differences in ecology, demographics, and the timing of extinction among the various moa species, their distribution areas collapsed after Polynesian settlement. The birds concentrated in the same cold, mountainous regions on New Zealand’s North and South Islands, which were the least affected by human activity. These “moa graveyards” continue to serve as important refuges for New Zealand’s remaining threatened flightless birds, such as the takahē, weka, kākāpō, and great spotted kiwi. Examples of such isolated and pristine areas include Mount Aspiring on the South Island and the Ruahine Range on the North Island.

The study emphasizes the importance of protecting remote, natural areas. “The key commonality among past and current refugia is not that they are optimal habitats for flightless birds, but that they continue to be the last and least impacted by humanity,” said Dr. Jamie Wood from the Environment Institute in an interview with Science.Daily.

The research also demonstrates that extinct species can provide invaluable insights for conservation efforts aimed at New Zealand’s living flightless birds. It highlights the necessity of safeguarding remote, wild habitats to protect the remaining bird populations from ongoing human-induced threats. Furthermore, the method offers a significant new approach to understanding past extinctions on islands where fossil and archaeological data are limited.