David Barber, the Queen's Swan Marker, holds a swan during the annual Swan Upping ceremony on the River Thames between Shepperton and Windsor on July 19, 2010. #

Teams raise a toast at the end of the first day of the annual Swan Upping census on July 18, 2016 on the River Thames, South West London. #

Swan Upping crew capture swans and cygnets during the annual Swan Upping Census on the River Thames at Staines, Middlesex on July 17, 2017. #

Neave Gilbert looks at a young cygnet after it is caught during the annual Swan Upping census on July 18, 2016. #

A Mute Swan is carried to be weighed during the annual Swan Upping census on July 18, 2016. #

'Swan Uppers' make their way through a gaggle of swans on the River Thames on July 20, 2015. #

A captured cygnet is measured on the bank of River Thames at Bray, on July 20, 2009. #

A swan is released back onto the river during the annual Swan Upping census on July 17, 2017. #

A swan is released back onto the river during the annual Swan Upping census on July 17, 2017. #

A "Swan Upper" struggles with a swan on the River Thames during the annual Swan Upping census in Maidenhead, Berkshire, on July 20, 2009. #

Swans and cygnets are weighed, measured, inspected and recorded in the annual counting of The Queen's swans near Chertsey, England, on July 17, 2017. #

Swan Uppers use their boats to corral swans before lifting them out of the river near London on July 19, 2010. #

A member of the swan upping team wears his swan upping tie during the annual census on July 17, 2017 on the River Thames. #

A cygnet is restrained whilst being examined during Swan Upping near Shepperton, England, on July 18, 2016. #

Swans and cygnets are caught, measured, assessed and tagged on the River Thames during the annual Swan Upping ceremony on July 15, 2013. #

Swan Upper Robert Coleman is attacked by a swan after falling into the River Thames on July 18, 2005. #