Eyles's harrier facts for kids

The Eyles's harrier (Circus teauteensis) was a large, extinct bird of prey that once lived in New Zealand. It was named after Jim Eyles, a paleontologist and museum director. This powerful bird was very similar to the swamp harrier, which is its closest living relative. They separated from each other about 2.4 million years ago.

New Zealand's Giant Bird of Prey

Eyles's harrier was a great example of island gigantism. This is when animals on islands grow much larger than their relatives on the mainland. An adult female Eyles's harrier weighed around 2.5 to 3 kilograms (5.5 to 6.6 pounds). This is more than twice the weight of a swamp harrier!

A Powerful Hunter

This giant harrier was a generalist predator. This means it hunted many different kinds of animals. It could catch prey as large as small eagles do, like animals weighing a few kilograms. New Zealand had no native mammals, so the harrier mostly hunted birds.

Its body shape was different from most other harriers. Because of its size, people first thought it was a huge hawk. It probably hunted daytime birds in a way similar to goshawks.

The Mystery of Its Name

The name and classification of this bird are a bit confusing. It was first described as Circus eylesi in the mid-20th century. These remains were found in Pyramid Valley on New Zealand's South Island.

However, similar bones were found about 100 years earlier. These older bones were found near the Te Aute region in the North Island. A scientist named Henry Ogg Forbes gave them the names Circus hamiltoni and Circus teauteensis. But these names were not officially accepted at the time. This is why Circus teauteensis is now the accepted scientific name.

A Possible Last Sighting?

A famous explorer, Charles Edward Douglas, wrote in his journals about seeing two very large raptors. This happened in the Landsborough River valley, probably in the 1870s. He even claimed to have shot and eaten them.

Some people wondered if these birds were the mighty pouakai (the Haast's eagle). But this is very unlikely. There hadn't been enough prey for Haast's eagles for a long time before then. Also, Māori stories from the 1800s said the pouakai hadn't been seen alive in many years.

Douglas's notes on wildlife are usually reliable. He estimated the birds had a three-meter wingspan. This is very large, even for a Haast's eagle. Eyles's harrier probably had a wingspan of just under 2 meters. So, it's more likely that Douglas saw Eyles's harriers. Even though Eyles's harrier also became extinct long ago, its diet made it more likely to have survived later.

Why Did It Disappear?

Today, the modern swamp harrier lives all over New Zealand. The bones of female swamp harriers can look similar to male Eyles's harriers. But all swamp harrier bones found in New Zealand are less than 1000 years old. This means they appeared after humans settled there.

There is no proof that swamp harriers and Eyles's harriers lived together for long in New Zealand. Even though they were different, they were similar enough in their habits. It seems that when the native Eyles's harrier died out, the swamp harrier was able to move in and thrive.