The Swan Marker to Britain's King Charles III says he and his team are happy to have discovered no decrease in the swan population along the Thames River during their annual count, known as swan upping, following "a downward spiral" in recent years. The steady numbers are "absolutely marvellous," says David Barber whose team have spent the day corralling swans and cygnets, before checking them over. Barber has been in the role for more than 30 years and has seen swan populations decline as a result of bird flu as well as human factors like "shootings". Each year, the Swan Marker is joined each year by counters from the Vinters and Dyers livery companies, who have retained the right to own swans on the Thames River since the 15th century. IMAGES AND SOUNDBITES