One of the world's longest-running animal research projects has now been running for 50 years.
The Bewick's Swan study at Slimbridge in Gloucestershire was started by Sir Peter Scott in 1964 after he noticed the birds had unique patterns on their bills.
Half a century on and more than 9,000 individual swans have been identified providing a unique insight into their lives.
The study is not only one of the longest running in the world, but it is the only one where researchers recognise the birds by their faces, rather than a ring around their foot, or wing. Sir Peter Scott was a keen artist and spotted the fact that they each had unique bills when he was painting them.
Sir Peter Scott's daughter Dafila helped paint and name the swans. As she grew up, she turned the study into more of a scientific research project.
It may seem like just a study of swans but great things have come out of it:
- Researchers have logged the stories of generations of Bewick's swans and their relationships
- The study has been followed by sister studies in five other countries, providing data on weather, climate and events have affected breeding, survival and interactions
- The study has led to an international Species Action Plan to maintain numbers and protect wintering and breeding sites.
- And now transmitters are being fitted to some birds to track their flight routes over the North Sea to help plans for offshore wind farms.
Here is Jonty Messer's report on the swan study.