In this 2006 photo released Wednesday, Nov. 19, 2008 by the New Zealand Science Media Centre shown is a yellow-eyed penguin. Australian and New Zealand researchers studying one of the world's rare and endangered penguins have uncovered a previously unknown penguin species that disappeared about 500 years ago.

By RAY LILLEY, Associated Press Writer

WELLINGTON, New Zealand – Researchers studying a rare and endangered species of penguin have uncovered a previously unknown species that disappeared about 500 years ago.

The research suggests that the first humans in New Zealand hunted the newly found Waitaha penguin to extinction by 1500, about 250 years after their arrival on the islands. But the loss of the Waitaha allowed another kind of penguin to thrive — the yellow-eyed species that now also faces extinction, Philip Seddon of Otago University, a co-author of the study, said Wednesday.

The team was testing DNA from the bones of prehistoric modern yellow-eyed penguins for genetic changes associated with human settlement when it found some bones that were older — and had different DNA.

Tests on the older bones "lead us to describe a new penguin species that became extinct only a few hundred years ago," the team reported in a paper in the biological research journal Proceedings of the Royal Society B: Biological Sciences.

Polynesian settlers came to New Zealand around 1250 and are known to have hunted species such as the large, flightless moa bird to extinction.

Seddon said dating techniques used on bones pulled from old Maori trash pits revealed a gap in time between the disappearance of the Waitaha and the arrival of the yellow-eyed penguin.

The gap indicates the extinction of the older bird created the opportunity for the newer to colonize New Zealand's main islands around 500 years ago, said Sanne Boessenkool, an Otago University doctoral student who led the team of researchers, including some from Australia's Adelaide University and New Zealand's Canterbury Museum.

Competition between the two penguin species may have previously prevented the yellow-eyed penguin from expanding north, the researchers noted.

David Penny of New Zealand's Massey University, who was not involved in the research, said the Waitaha was an example of another native species that was unable to adapt to a human presence.

"In addition, it is vitally important to know how species, such as the yellow-eyed penguin, are able to respond to new opportunities," he said. "It is becoming apparent that some species can respond to things like climate change, and others cannot. The more we know, the more we can help."

The yellow-eyed penguin is considered one of the world's rarest. An estimated population of 7,000 in New Zealand is the focus of an extensive conservation effort.

By David Ljunggren

Reuters

OTTAWA - Canada's Conservative government is interested in negotiating a climate change pact with the incoming administration of U.S. President-elect Barack Obama, which looks set to take a tougher line on the environment than did President George W. Bush, an official said on Thursday.

Obama's election could cause problems for Ottawa, since he favors tougher emission cuts than the Conservatives and has expressed alarm over what he sees as excessive U.S. reliance on "dirty oil" -- much of which comes from Canada's tar sands.

Concluding a pact could placate Washington by agreeing on tougher emissions standards while recognizing the importance of the tar sands, located in the western province of Alberta. Extracting oil from the sands produces huge amounts of greenhouse gases.

Canada is the largest single supplier of energy to the United States, accounting for around 9 percent of U.S. oil consumption and 15 percent of U.S. natural gas consumption.

The two nations have worked together before on green issues, most notably in 1991, when they signed a landmark agreement to cut acid rain.

"We do want to explore the possibility of a Canada/U.S. agreement similar to what we did on acid rain in the early 1990s," said a spokesman for Environment Minister Jim Prentice. He would not give further details.

Obama's targets for emissions cuts are much tougher than those set by Canada's Conservatives, who -- like Bush -- walked away from the Kyoto Protocol on climate change.

The energy industry in Canada is immensely influential and Prime Minister Stephen Harper, who comes from oil-rich Alberta, has long stressed that any measures designed to clean up the environment should not overly harm the oil patch.

He said on Thursday that he believed the incoming Obama administration would adopt tougher green policies "but will do so in a way that balances the environmental concerns with economic and energy concerns".

The Canadian Association of Petroleum Producers welcomed the idea of harmonized climate change regulations but warned against singling out the oil sands.

"We want clear and consistent policy that should be across the board and no discriminatory measures saying only here (the oil sands) and not there (the United States)," said Greg Stringham, a vice-president at the association.

Greenpeace campaigner Mike Hudema welcomed Obama's victory, saying it said could spell big changes for the oil sands.

"There is a growing movement to curb dirty oil imports and start building a clean energy future and it's time our governments get on board," he said in a statement.

But Harper, speaking to reporters in Toronto, suggested that Washington would have to balance its desire for more environmental regulations with Canada's importance as a key energy supplier.

"The United States faces major challenges if you're talking about energy security and Canada remains the most important and most secure U.S. source of energy. It's a reality for any president of the United States," he said.

By Alister Doyle, Environment Correspondent Reuters

OSLO - The Yangtze River dolphin, the Christmas Island shrew and the Venezuelan skunk frog are all victims in an alarming flood of extinctions, but how do scientists decide when such "possibly extinct" creatures no longer exist?

The United Nations says the world faces the worst spate of extinctions since the dinosaurs vanished 65 million years ago, with man-made threats such as rising populations, felling of forests, hunting, pollution and climate change.

Yet proving that any individual species has gone the way of the dodo necessarily demands long, fruitless searching.

"If there's one thing in my career I'd like to be proved wrong about, it's the baiji," said Sam Turvey of the Zoological Society of London, using another name for the Yangtze River dolphin.

Turvey spent almost 3 months this year interviewing Chinese fishermen in vain for sightings of the long-snouted dolphin, which has not been seen since 2002. Some colleagues in China are still looking.

The baiji was almost declared extinct in 2006 after an acoustic and visual survey of the river turned up nothing. Then, a blurry video gave experts pause, and it was rated "possibly extinct."

About 300 plant and animal species, including the Christmas Island shrew and the Venezuelan skunk frog are also "possibly extinct," the worst category short of extinction, according to the International Union for Conservation of Nature's (IUCN) Red List.

If Turvey's study turns up no firm evidence, it will likely push the Yangtze River dolphin into the "extinct" column, said Mike Hoffmann, who manages a global project to assess species for the IUCN and Conservation International.

It would be the first "megafauna" mammal -- one weighing more than 100 kg (220 lb) -- to die out since the Caribbean monk seal in the 1950s.

"To say something is extinct requires quite a lot of proof, of negative evidence, and may take many years to collect," said Craig Hilton-Taylor, who manages Red List.

Scientists working on the "possibly extinct" list rummage in the undergrowth for rare plants, frogs or rats, set up night-time traps for bats or moths, or scour the seabed for corals.

Some experts liken the difficulties to "proving" that the mythical Loch Ness Monster does not exist.

The Christmas Island shrew has not been seen on its Australian island since 1985. The Venezuelan skunk frog, known from a cloud forest habitat of 10 sq km (3.9 sq mile), has not been spotted despite repeated searches.

Despite the difficulties of proof, scientists say species are disappearing at an ever faster rate.

Some 76 mammals have gone extinct since 1500, a much faster rate than in previous centuries, and 29 are "possibly extinct" on the 2008 Red List.

BACK FROM THE DEAD

Extinct species have often unknown economic value, such as the Australian gastric brooding frog, which incubated its young in its stomach and might have pointed to ways to treat ulcers. Or South Africa's bluebuck antelope, which could have boosted tourism.

While most news is bleak, a few "Lazarus" species give cause for celebration -- last year, a lizard presumed extinct turned up on La Palma in Spain's Canary Islands after no sightings in 500 years.

Australian scientists were even delighted to find two dead night parrots in 2006 and 1990, taken as signs the reclusive species survives.

A few years ago the fabulous green sphinx moth, known from one Hawaiian island, was written off as extinct but then experts on another island were flabbergasted to catch one in a net.

Nevertheless, Hoffmann said Red List's demands for evidence meant that it probably underestimated the pace of extinctions. Searches have to be rigorous, at the right seasons, and in nearby habitats, with the correct equipment.

"Scientists want to be cautious" because of the finality of extinction, Hoffman said.

"Possibly extinct" is a category so bleak that it does not even include the critically endangered ivory-billed woodpecker -- subject of speculation about a U.S. comeback after reported sightings in Arkansas in 2004.

"It has never been listed as 'possibly extinct' because there were sightings 20 to 30 years ago in Cuba," Hilton-Taylor said. "There is still good habitat there."

One result of declaring a species extinct is that it inevitably ends cash for conservation -- lending agencies such as the Global Environment Facility use Red List data.

And, when one species goes extinct, new ones become endangered, as is happening on the Yangtze River, where the finless porpoise and the Chinese paddlefish, reported to grow up to 7 meters (23 feet), are also in danger.

"The problem with the Yangtze is that the threats are still there and they are escalating," Turvey said.

And there are wider threats. The U.N. Climate Panel said in 2007 that up to 30 percent of species will face increasing risks of extinction if temperatures rise by another 1 degree Celsius (1.8 Fahrenheit).

The panel, which says temperatures rose 0.7 C in the 20th century, also forecasts more droughts, heatwaves and rising seas linked to human emissions of greenhouse gases spurred mainly by burning fossil fuels.

In a 2006 report, Birdlife expert Stuart Butchart wrote that 150 bird species had gone extinct since 1500, or 0.3 a year. That was 30-300 times the background rate of extinctions -- a natural process deduced from fossil records.

And no one knows the number of species on earth -- one U.N.-backed study estimated 5-30 million against about 2 million documented so far. The U.N. Convention on Biological Diversity estimates they may be vanishing faster than they are found, at a rate of three per hour, the fastest in millions of years.