They may not be Sonny and Cher, but certain South American birds sing duets, taking turns as the tune goes along.

"Calling it a love song is probably too strong a word," says researcher Eric S. Fortune of Johns Hopkins University in Baltimore. But, he adds, the little wrens shift their heads around and move closer together as they sing.

The global output of heat-trapping carbon dioxide jumped by the biggest amount on record, the U.S. Department of Energy calculated a sign of how feeble the world's efforts are at slowing man-made global warming.

The new figures for 2010 mean that levels of greenhouse gases are higher than the worst case scenario outlined by climate experts just four years ago.

Shaquille O'Neal is suing a former information technology employee the former NBA great claims invaded his privacy by selling personal emails that damaged his reputation.

The lawsuit was filed against Shawn Darling in Miami-Dade Circuit Court.

The U.N. says a medical emergency has been declared in northern Angola following confirmation a 14-month-old boy has contracted a new wild polio virus.

In a statement Thursday, the U.N. children and health agencies said the boy lives in an isolated region in Uige province along the Congolese border.

Police recovered two stolen paintings by Dutch masters and handed them back Thursday to the provincial museum they were stolen from five months ago. Three suspects are in custody, police said.

The 17th-century paintings, a depiction of two laughing boys by Frans Hals and a forest landscape by Jacob van Ruisdael, were snatched from the Hofje van Mevrouw van Aerden museum in the central town of Leerdam in late May.

A Japanese utility operator has denied any problematic nuclear reactions at a tsunami-hit power plant, saying a radioactive gas in one of the damaged reactors came from spontaneous fission that occurs in any idle reactor.

The operator this week found radioactive xenon, initially hinting unexpected nuclear fission and injected boric acid as a precaution against further nuclear reactions.

A newly proposed solution to an ancient enigma is reviving debate about the nature of a mysterious prehistoric site that some call the Holy Land's answer to Stonehenge.

Some scholars believe the structure of concentric stone circles known as Rujm al-Hiri was an astrological temple or observatory, others a burial complex. The new theory proposed by archaeologist Rami Arav of the University of Nebraska links the structure to an ancient method of disposing of the dead.

Amazon.com Inc. said Thursday that it is starting a lending library for Kindle owners, letting them borrow one electronic book per month.

Borrowers have to subscribe to Amazon's Prime service, which provides free two-day shipping and streaming movies for $79 per year.

Rescued Chilean miner Edison Pena is returning to run New York City Marathon.

Pena completed the marathon last year, less than a month after he and 32 other miners were rescued after being trapped underground for 69 days.

Cuba announced Thursday it will allow real estate to be bought and sold for the first time since the early days of the revolution, the most important reform yet in a series of free-market changes under President Raul Castro.

The law, which takes effect November 10, applies to citizens living in Cuba and permanent residents only, according to a red-letter headline on the front page of Thursday's Communist Party daily Granma and details published in the government's Official Gazette.