Overwintering bird surveys

Dunlin flock in flight © Deryn Hawkins

We take you through some of the techniques and findings from our overwintering bird surveys

The Trust’s ecology team is currently leading a project for Bird Aware Solent collecting baseline monitoring data at several sites along the Solent coastline, many of them the estuarine areas where freshwater meets the sea. These surveys help highlight how important these areas are for wildlife and why they must be protected from destruction.   

Overwintering bird surveys are carried out to help us understand the species and numbers present on coastal sites, including the Trust’s Southmoor Nature Reserve. These two-hour surveys involve watching the birds from different vantage points to record their numbers and activity (for example, where birds are flying). The habitats change dramatically at high and low tide, being used by different sets of species for roosting (at high tide) or foraging (at low tide). Visitor surveys also help us understand how people are using the sites and the potential disturbance effects on overwintering birds, many of which are rare or need special protection. 

Results so far this year have been positive, with good numbers of brent geese recorded as well as numerous waders such as dunlin (notable large flocks at Hayling Island), redshank, oystercatcher, turnstone, grey plover, ringed plover and curlew. Ducks such as wigeon and red-breasted merganser overwinter on these sites and have also been recorded in good numbers. Curlew, a red listed bird of conservation concern, have been frequently seen, despite the UK population having declined in recent years, perhaps indicating targeted conservation work is beginning to pay off for the birds. 

At Southmoor Nature Reserve, the main species seen have been brent geese, dunlin, redshank, oystercatcher, turnstone and curlew. And while not a a target species on the overwintering bird surveys, one of the particular highlights for the team has been a very friendly kestrel, frequently seen hovering above them during surveys. 

The project involves habitat creation and enhancement at these sites as well as measures to reduce disturbance to overwintering birds, for example, interpretation boards/signage and boardwalks to divert people away from the most sensitive areas. Results of the surveys, which were conducted prior to these works, will be used and compared with future monitoring surveys to assess how effective these measures have been at diverting people and raising awareness.  

Unfortunately, during both the visitor and bird surveys, disturbance has been noted multiple times - mostly people letting dogs off leads across mudflats and around feeding birds, causing birds to take flight and expend precious energy. However, it is hoped that installing measures such as those mentioned above will reduce disturbance to birds and help keep these special sites as havens for wildlife.