A British ornithologist has helped find a completely new species of owl.
Magnus Robb, 43, formerly from Edinburgh, and his team made their discovery in Oman in the Middle East.
Listen to the owl hoot here:
The species, completely new to science, is a little bigger than the tawny owl and has been named the Omani Owl.
Tracked down in a remote mountain region of Oman, the owl was first noticed in March this year when it hooted while researchers were making sound recordings of another species.
Mr Robb, a sound-recordist and author, had not heard anything like it before.
He said: "I was recording a species I know well, when I noticed some faint owl-like hooting in the background with a rhythm I had never heard before.
In May and July the team made two more research trips to look for new individuals, gather photographs and sound recordings, and observe behaviour.
After analysing it, they concluded this was indeed a new owl for science, and the first bird species to be discovered in Arabia for 77 years.
Prince Charles took part in a traditional sword dance on a visit to the ancient fort of Nizwa in Oman.
The Duchess of Cornwall looked on as Charles was handed a double-bladed sword and shield, and the music started up.
The Prince began to shuffle and wave the sword, mimicking the dancers who were performing sword tossing and mock fighting around him.
As the royal couple toured the stronghold they were greeted by children waving Union flags and met people who were making mats and baskets.
The visit is part of their nine-day tour of the Middle East.
Prime Minister David Cameron welcomed today's deal announced between BAE Systems and Oman to deliver 20 aircraft by 2017. Speaking in Oman he said he was looking forward to meeting the Sultan of Oman to discuss regional issues.
"This deal is worth £2.5 billion pounds, it helps protect and defend thousands of jobs in the UK."
"Britain and Oman have a very close defence partnership, intelligence partnership, very close relations, and I am looking forward to meeting with the Sultan this afternoon to talk about all sorts of regional issues, obviously including Iran."
The Prime Minister's plane has arrived in Muscat, Oman.
Defence giant BAE Systems has won a £2.5 billion deal to sell 20 aircraft to Oman, helping to sustain thousands of jobs in the UK.
The contract has been welcomed by Prime Minister David Cameron who will visit the Middle East state today.
The aircraft will be built in the UK from 2014, and will help sustain 6,000 high technology and engineering jobs in sites across Lancashire and East Yorkshire.
The chief executive of British defence manufacturer BAE Systems is in Oman to sign the deal to provide 12 Typhoon aircraft and eight Hawk trainer aircraft.
British defence manufacturer BAE Systems has agreed a major new deal with the Gulf state of Oman.
The contract will see BAE provide Oman with 12 Typhoon aircraft and eight Hawk trainer aircraft by 2017.