On New Zealand’s remote Chatham Islands, scientists have uncovered the story of a bird that defied expectations, the Rēkohu shelduck. Rather than taking to the skies, this remarkable species evolved to live almost entirely on foot.
For nearly 400,000 years, it thrived without predators, developing shorter wings and powerful legs suited for life on the ground. Its discovery not only sheds light on island evolution but also offers a poignant reminder of how quickly unique species can vanish once humans arrive.
This article is for general information and educational purposes only. Photos are for illustrative purposes only and only depict a species that looked similar.
Bones That Waited Centuries To Tell Their Story
In the 1990s, palaeontologist Phil Millener from the Museum of New Zealand Te Papa Tongarewa unearthed mysterious bones on the Chatham Islands. Though he suspected they belonged to an unknown bird species, the technology at that time could not confirm it.
The fossils remained in museum collections for decades, waiting for modern DNA analysis to reveal their secrets. When researchers finally examined them using advanced genetic tools, they confirmed these were not paradise shelducks but a new, entirely distinct species that had evolved in isolation.
A Journey From Mainland New Zealand
Around 390,000 years ago, the ancestors of the Rēkohu shelduck were paradise shelducks from mainland New Zealand. They made a remarkable 785-kilometre flight east to the Chatham Islands, known as Rēkohu to the Moriori people.
There, they encountered a predator-free environment with abundant food and strong winds that made flying inefficient. Over time, evolution favoured birds that thrived on the ground, leading to a gradual shift from flying to walking as their primary mode of movement across the island terrain.
The Chatham Islands
The Chatham Islands were home to an extraordinary array of unique bird species, with 64 breeding species at the time of human arrival. Remarkably, 34 of these existed nowhere else on Earth.
With no mammalian predators, many evolved to be flightless, including the Rēkohu shelduck and the Chatham Island duck. These islands became a living laboratory of evolution, revealing how isolation drives species to adapt in unexpected ways and develop characteristics perfectly suited to their specific environment without outside threats.
Collaboration With The Moriori People
In naming the new species, scientists worked with the Hokotehi Moriori Trust, the guardians of Rēkohu’s biodiversity. The bird’s name, Tadorna rekohu, reflects both scientific discovery and the deep cultural connection the Moriori people maintain with their environment.
This partnership ensures that the species’ identity honours the island’s heritage as well as its natural history. Collaboration between researchers and indigenous communities creates a more complete understanding of both past ecosystems and the cultural significance of extinct species to the people who first knew them.
A Short-Lived Evolutionary Experiment
Sadly, the Rēkohu shelduck’s ground-dwelling lifestyle became its undoing. When the first Polynesian settlers arrived, these large, flightless birds made easy prey.
Within a short time, they vanished, their 390,000-year evolutionary journey cut short by human hunting. Had they survived, they might have joined the ranks of the world’s fully flightless birds, like the kiwi or dodo. Their story reminds us how vulnerable specialized species become when new predators, especially humans, enter their isolated worlds without warning or time for adaptation.
