Tool-kit for wader conservation wadertales

Reserve managers and sympathetic landowners have become very good at creating the sort of habitats that attract breeding Lapwings. Autumn and winter grazing can be manipulated to produce short swards, whilst adding in shallow pools and foot-drains (linear features running through fields) increases feeding opportunities for chicks. See Restoration of wet features for breeding waders on lowland grassland

The RSPB has invested heavily in time and equipment to deliver these lowland west grasslands, on their own land, on other nature reserves and on commercial farmland. By working with Natural England, they have helped to shape agri-environment schemes that can be used to deliver payments to farmers who are well-placed to create habitat that suits breeding waders.

In the east of England, there are now more than 3000 hectares of this attractive, well-managed wet grassland habitat, designed to be just right for species such as Lapwing. The graph alongside, drawn using RSPB data, shows the number of pairs of Lapwing (green), Redshank (red) and other waders (Oystercatcher, Avocet & Snipe: blue) in Berney Marshes RSPB reserve in eastern England for the period 1986 to 2016. There were early successes, as new areas were purchased and transformed, but growth in wader populations has not been sustained, despite ongoing improvements in land management. What is preventing further recovery? Demographic processes

In a paper in the Journal of Ornithology, Maya Roodbergen et al used demographic data collated across Europe to show that there had been long-term declines in nest survival and increases in nest predation rates in lowland wader species. One of the main focuses of management action at Berney Marshes is to maximise Lapwing productivity but nesting success is still below 0.6 chicks per pair in most years (see graph), which is the minimum estimated productivity for population stability (Macdonald & Bolton). Not enough chicks are being hatched, with the vast majority of egg losses being associated with fox activity. Controlling foxes

The obvious solution for breeding waders must surely be to shoot foxes? It’s not that simple. In a multi-year, replicated experiment to assess the impact of controlling foxes and crows, RSPB scientists showed that there were no clear improvements in wader nesting success; effectiveness is very much site-specific. Much may well depend on how much fox control there is in the surrounding area.

If fox impacts cannot be reduced sufficiently through lethal control, perhaps it is possible to reduce their effects on waders by understanding the ways in which foxes forage and to adapt the habitat appropriately? Work by Becky Laidlaw and others has shown that Lapwing nest predation rates are lower close to tall vegetation and in areas with complex wet features. However, Becky has also shown that management to create these features, even in areas of high wader density and effective predator mobbing, is only likely to achieve small reductions in nest predation. There is a WaderTales blog about this: Can habitat management rescue Lapwing populations? Excluding foxes

• Whole-site protection will suit semi-colonial species such as Lapwing. Although expensive to install, permanent fences can require relatively little maintenance and can potentially be powered by mains electricity. One disadvantage may be that the presence of large numbers of chicks can attract avian predators, such as birds of prey, which are themselves conservation priorities and hence difficult to manage.

• Field-scale fences usually rely on batteries, which need to be checked and changed, and fences need maintenance, as the grass grows and can short out the bottom strands. However, deployment at the field-level allows for dynamic use within a farming landscape and in accordance with agri-environment schemes. New research by RSPB and the University of East Anglia aims to see if fences need only to be deployed for relatively short periods. If pairs nest synchronously then groups of birds may be able to maintain the ‘fence-effect’ by mobbing predators, when a temporary fence is removed.

Although it might be possible to improve the habitat that is available for breeding waders and to reduce predation pressure, it is sometimes too late to boost numbers – simply because populations have shrunk to too low a level. At this point, head-starting (rearing chicks from eggs) may be appropriate. This blog celebrates the success of the first year of a joint initiative by RSPB and WWT ( Project Godwit) to increase the local population of Black-tailed Godwits in the East Anglian fens: Head-starting Success. In conclusion