The Lincoln Swan project: Swans and Community Science

By Dr Jenny Dunn, University of Lincoln, UK

Mute swans (Cygnus olor) are an important symbol of the city of Lincoln in the UK, dating back to the rebuilding of Lincoln cathedral in 1185, and St Hugh – the patron saint of swans.

Historically, large juvenile groups would over-winter on the Brayford Pool in the city centre, with a Wetland Bird Survey (WeBS) high count of 111 swans in 2007/08. However, recent surveys suggest that these numbers are declining, with WeBS counts in the low teens since 2016/17. Many environmental factors may drive this apparent decline, such as a decreased food availability, fishing lines or lead weights in the waterways leading to either a reduction in survival of adult or juvenile swans, or competition between swans for territories, leading to the relocation of young swans from the city centre to other areas.

In 2017 we started a programme of colour ringing swans on the waterways in and around Lincoln, funded by the University of Lincoln and with assistance from Kane Brides of the Wildfowl & Wetlands Trust, and Dan Sidley of the Yorkshire Swan and Wildlife Rescue Hospital, to allow us to look at the movement and dispersal of individual birds in the population. Each swan has a metal ring on one leg, and a yellow colour ring on the other with the letter L (or Y, in a year when our colour ring delivery was late and we had to borrow some Yorkshire rings!) followed by three numbers. We have now ringed over 250 swans in and around Lincoln and are starting to get some great data on resightings, both from within Lincoln and from further afield.

In 2020, we started receiving more colour ring re-sightings via email as people were taking their daily exercise more locally during the first Covid-19 lockdown. This drove us to develop a community science project using the phone App Epicollect, to allow members of the public to register with the project and submit swan sightings via a smartphone (see From a data collection and management perspective, the App allows data to be collected in a standardised way (although some checking and data cleaning is always necessary), and allows precise GPS recording of each bird’s location. The App also allows volunteers to collect data on breeding success, group size, dispersal dates for cygnets, and any other observations or causes for concern.

From May 2020, when we launched the App, to now, we have received over 3,100 sightings via the App. This is intended to be a long-term project examining the ecology, behaviour, health and welfare of the Lincoln swan population, so the more volunteer data collectors who use the App to report their sightings, the more we can use the data to understand the needs of the swan population. We are interested in every sighting of the birds, even if they are in the same place every day.

We are asking UK birders to keep an eye out for any colour ringed swans you see, and report any yellow colour rings starting L or Y to us! If you see these birds regularly, please sign up for the App here (you will need a gmail account to use Epicollect): More information about the project is available on the Lincoln Swan project website:, and you can follow the swans on Twitter @LincolnSwans, or contact us at

This project is a collaboration between Dr Jenny Dunn, whose research focuses on avian ecology and bird-parasite interactions, Dr Laëtitia Maréchal, who works on human-animal interactions, and Dr Teresa Romero, who works on animal social behaviour and cognition. All are based at the University of Lincoln, UK. Ethics reference: UoL2020_2236.