Skip to main content


Title: Associations of wintering waterfowl with freshwater on the mudflats of East Anglian estuaries
Author: N.O.M. Ravenscroft
Document Type: Monograph
The associations of wintering waterfowl with freshwater that flows over the intertidal mudflats of four East Anglian estuaries were studied between 1996 and 1998. The research was initiated in response to concerns over the impact of further reduction in freshwater inputs to these estuaries through abstraction. The wintering bird populations of these estuaries contribute to internationally recognised and designated conservation sites. The numbers and densities of some waterfowl in corridors around freshwater flows were consistently greater than those on the remaining mudflats of all the estuaries studied. Shelduck, wigeon, pintail, grey plover and redshank showed the strongest relationships overall, and large proportions of the estuary populations of these species occurred around flows. The potential influence of freshwater on the distribution of waterfowl is discussed. Among possibilities are its effect on local microclimate, prey density or availability, as well as the shelter provided by channels. Little is known about impact of reducing the discharge of flows, although its effects on remaining mudflats may be similar to the displacement of birds from other intertidal grounds. It is also possible that loss of freshwater sources on mudflats could affect birds from other estuaries as well as on surrounding land.
Publisher: Environment Agency
Publication Date: 1998
Publication Place: Suffolk
Subject Keywords: EstuariesWaterfowlMudflatsGeographical distributionPopulation surveyDischarge (hydrology)
Geographic Keywords: East AngliaOrwellStour (Suffolk)Stour catchment
Extent: 15; + appendices
Total file downloads: 316

Download PDF    Display PDF in separate tab