The annual Swan Upping, a tradition dating back over 800 years, commenced on the River Thames. This event, held under the auspices of King Charles III, involves a census of the Royal swan population along a five-day stretch of the river from Sunbury near London to Abingdon near Oxford. Participants, dressed in scarlet uniforms and using wooden skiffs, count adult swans and monitor cygnets by tagging, weighing, and health checks. The Swan Marker reported that the current census found no decline in the swan population, reversing a downward trend observed in recent years. The event continues to be a significant cultural and environmental activity in Britain.