Discuss as:

Bird count: Census of the swans on the River Thames

Carl Court / AFP - Getty Images

Swans are captured on the River Thames in southeast England on Monday, July 18, during 'Swan Upping.'

Carl Court / AFP - Getty Images

Swans are captured during the annual 'Swan Upping' on the River Thames in southeast England, on Monday.

Carl Court / AFP - Getty Images

A cygnet's head is measured during the annual swan census or 'Swan Upping' on the River Thames in south-east England, on Monday.

According to AFP, 'Swan Upping' is the annual census of the swan population on stretches of the River Thames, spanning the counties of Middlesex, Surrey, Buckinghamshire, Berkshire and Oxfordshire. The census dates from the twelfth century when the Queen claimed ownership of all mute swans and is overseen by the Queen's Marker.