Managing a food web: impacts on small mammals of managing grasslands for breeding waders

Conservation management of landscapes often targets species of conservation concern, but this can have repercussions for other components of the food web which may, in turn, indirectly influence the target species. In Western E urope, many lowland wet grasslands are managed to encourage declining breeding wader populations but the benefits of creating habitat conditions that attract waders are often limited by increased predation rates. As predator activity may be influenced by the relative availability of different prey sources, we investigate the influence of habitat management for waders on the distribution and activity of the small mammal prey of mammalian predators. Livestock grazing to create the short sward structure that attracts breeding waders on wet grasslands results in areas of tall, dense vegetation being largely restricted to verge areas outwith fields. Through both ink tracking tunnels and field‐sign searches, we found small mammal activity to be almost entirely restricted to swards of > 20 cm height and > 80% ground‐level cover which, in this landscape, is only found in verges and field edges. The creation of extensive areas of short grass to attract breeding waders may therefore be substantially reducing the abundance of mammal prey for the predators that are limiting wader productivity on many sites. Using this information to plan small mammal habitats within these landscapes may be a means of reducing the predation pressure on breeding waders, and there is an urgent need to establish whether predation rates on wader nests and chicks are lower when small mammals are abundant.