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Management of wet grassland habitat to reduce the impact of predation on breeding waders: Phase 2 - BD1327

Description
There have been widespread and severe population declines of breeding wading birds on lowland wet grassland in UK and elsewhere in Europe. These declines have been associated with the loss and degradation of breeding habitat mainly through changes in agriculture such as drainage and intensification of grassland management. Whilst there is clear evidence that appropriate sward and hydrological management are essential for the maintenance of healthy wader populations, recent work indicates that in some situations high levels of predation on wader nests or young may prevent population recovery even where habitat conditions are good. Work undertaken under Phase 1 of this project showed that the most important predators of wader nests are likely to be mammals such as foxes. However, the key predators do not specialise on wader nests and it is likely that nests are consumed as they are encountered opportunistically rather than being actively sought. Lapwing nests suffer lower rates of predation when located away from the field edge, in fields where the densities of nesting lapwing are high and on sites where predator abundance is lower. Predator abundance can be reduced by lethal predator control but this is not a cost-effective long-term solution and is unlikely to be favoured as an agri-environment option. Thus, finding a non-lethal solution to this important conservation issue is now of great importance.

The proposed project will make use of lapwing nesting habitat preferences in an experiment that will attempt to manipulate nest distribution and thereby reduce levels of predation. Lapwing prefer to nest on bare, disturbed ground or short swards and close to areas of surface water. We will exploit these preferences to encourage birds to nest in high densities away from field edges, which is expected to result in higher rates of nest survival. We will also examine the effect of this manipulation on the distribution and survival rates of nests of redshank. Three habitat manipulations will be examined, comparing nest distribution and survival rates with those observed in unmanipulated, control fields:

1. Unsuitable field margins. Margins will be made less attractive for nesting lapwing by increasing the height and reducing the structural complexity of vegetation through lack of mowing the previous autumn and a light application of fertiliser to promote early grass growth.

2. Creation/maintenance of wet features (foot-drains and pools) in the centres of fields and removal of such features close to field margins.

3. Establishment of a mosaic of bare, vegetated and disturbed ground in field centres.

The project will provide Defra with management recommendations for agri-environment schemes and therefore an opportunity for landscape-scale restoration of wader populations under reduced levels of predation.
Objective
Objective 1: To investigate the effects on in-field wader nesting distribution, density and breeding success of the following three habitat manipulations:
i) field margins made less attractive for nesting through fertilising and lack of mowing to create taller swards
ii) field centres made more attractive by ensuring availability of wet features
iii) field centres made more attractive by producing a mosaic of disturbed bare and vegetated ground.

Objective 2: To investigate the effects of three habitat manipulation treatments on predator distribution and foraging behaviour.

Objective 3: Quantify the economic cost of each manipulation and provide an overall evaluation of the most cost-efficient option to benefit breeding waders.
Project Documents
• Final Report : Management of wet grassland habitat to reduce the impact of predation on breeding waders: Phase 2.   (733k)
Time-Scale and Cost
From: 2008

To: 2010

Cost: £184,850
Contractor / Funded Organisations
Royal Society for Protection of Birds
Keywords
Agricultural Land              
Environmental Protection              
Grasslands              
Land