New Zealand swan facts for kids

The New Zealand swan or poūwa (Cygnus sumnerensis) was a large swan that lived in New Zealand and the Chatham Islands. Sadly, it is now extinct.

Scientists first found bones of this swan in 1889. At first, they thought it was a different type of swan from the Australian black swan (Cygnus atratus). This was because its bones were a bit bigger. Also, black swans were not brought to New Zealand until 1864.

For many years, scientists debated if it was a unique species. But from 1998 to 2017, most thought it was just a New Zealand group of black swans. Then, scientists studied ancient DNA from its fossil bones. This DNA proved that the poūwa was indeed its own species. It was much larger and heavier than its Australian cousin.

How the Poūwa Was Discovered

The first bones of the New Zealand swan were found in September 1889. They were in Monck's Cave, near Christchurch, in a place called Sumner. The cave owner, Henry Monck, found the bones. He showed them to John T. Meeson and Henry Forbes. Forbes was the Director of the Canterbury Museum.

The swan bones were found with other animal bones, like moa and fish. There were also tools like adzes and spears. This showed that early Māori living in the cave hunted these swans. Forbes studied the bones and named the new swan species Chenopis sumnerensis. He named it after the Australian black swan (Chenopis atrata) and the place where it was found, Sumner.

Forbes noticed that the bones were larger than those of the Australian black swan. He also knew that the cave had been closed before black swans were brought to New Zealand in the 1860s. This meant the bones had to be from a native New Zealand swan.

Why Its Name Changed (and Changed Back!)

For a while, scientists were not sure about the New Zealand swan. In 1955, a scientist named Walter Oliver thought the original bones Forbes found were lost. So, he gave the swan a new name, Cygnus chathamensis, using bones from the Chatham Islands.

A few years later, Forbes's original bones were found again! This meant C. chathamensis was actually the same as C. sumnerensis. So, the older name, C. sumnerensis, was used again.

Then, in 1998, another scientist, Trevor Worthy, compared many New Zealand swan bones with Australian black swan bones. He thought they looked very similar in size. Because of this, scientists believed the New Zealand swan was just a group of black swans that had flown to New Zealand long ago. They thought early Māori settlers had hunted them until they disappeared.

The Poūwa's True Identity Revealed

The story changed again when scientists used ancient DNA. They took DNA from 39 fossil bones found in museums. This helped them look closely at the relationship between New Zealand and Australian swans.

The DNA showed that the swans from mainland New Zealand and the Chatham Islands were a special group. They had been separate from Australian swans for maybe 1 to 2 million years! They were different enough from Cygnus atratus to be their own species. So, the name C. sumnerensis was used again.

The researchers chose the Moriori name poūwa for the species. This name comes from a legend about a large bird that lived in Te Whanga lagoon on Chatham Island. People could still find its bones in the sand dunes.

Scientists believe that the first Polynesian settlers caused the poūwa to become extinct. This happened around 1450 AD on the mainland and 1650 AD on the Chatham Islands.

What the Poūwa Looked Like

The poūwa was much bigger than the Australian black swan. Scientists estimate it weighed about 10 kilograms (22 pounds). The Australian black swan weighs about 6 kilograms (13 pounds). The poūwa stood about 1 meter (3.3 feet) tall. One scientist described it as "more like a rugby player" compared to the "smaller and slender soccer-player physique" of the Australian swan.

The poūwa had shorter wings and longer legs. This suggests it was slowly losing its ability to fly. Other New Zealand birds, like Finsch's duck and the New Zealand goose, also became flightless. Scientists think the poūwa probably had black feathers, just like the Australian black swan. However, we cannot know for sure from just bones.

After the poūwa died out, some black swans from Australia occasionally flew to New Zealand. But it wasn't until the 1860s, when people deliberately brought black swans to New Zealand, that they became common. Today, there are about 50,000 black swans in New Zealand.