Feeding distributions

Traditionally in the UK, wintering geese and swans foraged mainly in natural wetland areas, e.g. lakes and saltmarshes, feeding on aquatic plants such as Potamogeton, Zostera and Scirpus. However, over the most recent half century there has been a large increase in the use of agricultural areas, with flocks feeding on waste root crops, grain stubbles, winter cereals, improved pasture and other farmland habitats.

Feeding_Geese

This shift in foraging behaviour is mainly due to changes in land use, particularly the increase in agricultural intensification that have resulted in a large increase in food availability in farmland areas, which the birds are successfully exploiting. With many goose and swan populations rapidly increasing, partly as a result of this shift in foraging behaviour, the pressure on agricultural land as foraging areas is growing and, inevitably, this may lead to conflict between birds and people, both in terms of managing land for agriculture and development, and for safe-guarding habitats for geese and swans protected under European law.

As a consequence, information on goose and swan feeding distributions is becoming increasingly important and sought after. Feeding distribution data are frequently required by landscape planners and government undertaking Environmental Impact Assessments as part of the planning stages of land development work. With the continued development of green energy generation, planning applications are increasingly being submitted for onshore wind farms and solar farms. Geese and swans can be affected by these through collision mortality, displacement from feeding sites and disturbance. Therefore, data on the feeding distribution of geese and swans can help to inform the appropriate siting of green energy and other developments.

In the UK, Special Protection Areas (SPAs) have been designated for all migratory goose and swan species. However, as most surveys of geese and swans collect data at roost sites, the majority of these protected areas do not adequately protect feeding areas (largely due to a lack of knowledge with which to underpin this). Guidance on SPA designation indicates that agricultural areas and other non-natural habitats are appropriate for designation if they are deemed the most suitable locations, but in practice this will be difficult to implement at most key sites. Therefore, data on goose and swan feeding distributions, particularly around SPAs, are more likely to be used to implement effective management of the landscape for these species, thereby maintaining adequate feeding opportunities in preferred areas and avoiding conflict with human activities., Further background information on this topic is available from the UK SPA/Ramsar Scientific Working Group – see 2002 overview of Cropped Habitats Information Project.

To date, there have been few bespoke studies of feeding distributions, and no systematic monitoring. However, a lot of ad hoc. data exist from GSMP surveys, such as age assessments and resightings of marked birds, and these have recently been used to map known feeding distributions for several species. Other sources, such as records sent to county bird recorders or BirdTrack can also be used. WWT is looking to develop more systematic monitoring of goose and swan feeding distributions in some of the key areas.

WWT feeding distribution projects

WWT have undertaken several projects looking at the feeding distribution of geese in the UK. Below are the most recent projects; older reports can be found on our Reports and newsletter page.

Mapping feeding distributions of Pink-footed and Greylag Geese in Scotland and England.

In 2012, WWT undertook a desk study, funded by WWT and Scottish Natural Heritage, which aimed to produce sensitivity maps based on the known feeding distribution of Pink-footed and Iceland Greylag Geese in Scotland, and included special reference to the SPA network (Mitchell 2012). A similar study was also undertaken in 2013, funded by WWT and Natural England, to develop sensitivity maps showing the known feeding areas of Pink-footed Geese in England (Brides et al. 2013.). The resulting sensitivity maps can be used to aid the location of onshore wind farms by providing an indication of where developments are most likely to come into conflict with Pink-footed and Greylag Geese. The maps are an indicative tool that enables the identification of areas where impacts of turbines on geese may be of concern. This work assists government to undertake a strategic approach to planning the location of wind farms in order to help safe-guard bird species. Download Mitchell (2012) Download Brides (2013)

Feeding areas for Dark-bellied Brent Geese around Special Protection Areas in the UK

In 2003, WWT undertook a survey to identify and characterise the inland feeding areas of Dark-bellied Brent Geese around the 19 SPAs in the UK for which it is a qualifying species. Historically, Dark-bellied Brent Geese fed exclusively on intertidal habitats during the winter in the UK, predominantly grazing on Zostera and green algae. However, since the 1970s, there has been a significant increase in the use of inland agricultural habitats and many of these areas fall outside the boundaries of SPAs for which Dark-bellied Brent Goose qualifies as an interest feature. The study aimed to identify the location of feeding areas used by the geese around the SPAs, identify the relative importance of these areas in terms of the number of geese present and the frequency of use, and characterise the feeding areas in terms of land use, distance from the roost, field size, visibility and disturbance (these being factors that influence the suitability of inland sites for Dark-bellied Brent Geese). Download report