• Haast's eagle was the largest eagle known, weighing up to 40 pounds with a 10-foot wingspan, preying on the giant moa of New Zealand.
• Genetic studies indicate that the Haast's eagle evolved rapidly from smaller Australian raptors, demonstrating significant island gigantism.
• The extinction of the moa due to overhunting and habitat loss by Polynesian settlers led to the Haast's eagle's demise.

The Haast's eagle (Hieraaetus moorei) was an apex predator in pre-human New Zealand, notable for its immense size and specialized hunting strategies. It evolved to hunt the moa, a large flightless bird, showcasing a unique predator-prey relationship. The eagle's extinction, linked to the moa's disappearance following human settlement, highlights the vulnerability of island ecosystems and the impact of human activity on native species.

• What: The Haast's eagle was the largest eagle known to science, preying on moa in New Zealand before human settlement.
• Who: The key individuals and groups involved are the Haast's eagle, the moa, Polynesian settlers (ancestors of the Māori), 19th-century explorer Julius Haast, Dr. Joanne Cooper (Natural History Museum in London), and Michael Knapp (University of Otago).
• When: The Haast's eagle existed in New Zealand before Polynesian settlement around 1250 AD. The moa went extinct within two centuries of Polynesian arrival, leading to the eagle's demise. The eagle's bones were discovered in the 1860s. Genetic studies were published in 2005.
• Where: The events occurred in New Zealand, where the Haast's eagle and moa were native. Genetic links point to Australia as the origin of the eagle's ancestors.

The Haast's eagle represents a remarkable example of island gigantism and rapid evolution. Its specialized adaptations for hunting the moa highlight the unique ecological dynamics of pre-human New Zealand. The extinction of both species underscores the fragility of island ecosystems and the significant impact of human activity on biodiversity. The ongoing genetic research aims to uncover the specific genes responsible for the eagle's rapid growth spurt.

It’s always been a puzzle with Haast’s eagle. The head end looks quite vulture-like, while the feet end looks very eagle-like.

That’s a staggering rate of change. I know of no other instance where natural selection led to such substantial growth over such a short period.

There was huge amounts of meat that wasn’t taken. That scenario would have quickly selected for the largest eagles.

But if it could successfully hunt a 250-kilogram moa, then 80-kilogram humans were possibly on the menu.

The Haast's eagle was a unique and formidable predator, perfectly adapted to its environment in pre-human New Zealand. Its extinction, driven by the loss of its primary prey, serves as a cautionary tale about the impact of human activities on vulnerable species and the importance of conservation efforts to protect remaining biodiversity.