Influence of ground predators and water levels on Lapwing Vanellus vanellus breeding success in two continental wetlands

Abstract

Insufficient productivity has driven population declines in grassland breeding waders with high levels of predation limiting productivity in many wetland reserves. We studied hatching and fledging success of Lapwings Vanellus vanellus in two continental river floodplains (Havel and Oder) differing in water regime and density of Red Foxes Vulpes vulpes to assess the effects of increased water tables as a management option. Nest predation rates were high on dry sites as well as on flooded grasslands in all areas irrespective of fox litter density. Carnivores formed the majority of the predators identified and eggshell remains suggested that mustelids took proportionally more nests at low fox densities. At unsuccessful nests on flooded grassland, an increasing incidence of nocturnal disturbances prior to predation indicated an influx of carnivores as the sites dried out. Brood survival depended on the availability of wet features, and productivity was thus linked to water tables in June in one area (Havel). Productivity was insufficient to maintain local populations in all areas and years except for two occasions related to increased water tables. Retaining high water tables throughout the breeding season therefore remains an important management option for waders on continental wet grasslands.

Exclusion of ground predators improves Northern Lapwing Vanellus vanellus chick survival

“…In the long term, management should improve the habitats of endangered focal species while simultaneously lowering the attractiveness of habitats to ground predators, e.g. by altering the water table (Bellebaum & Bock 2008, Eglington et al. 2008).…”

Observations on Yellow-Wattled Lapwing, Vanellus malabaricus (Boddaert, 1783) in South West Bengal, India

“…The characteristic dense vegetation in the paddy fields, from July onwards, serve as refuge for these birds against natural enemies, as observed in other species (MacDonald and Bolton 2008;Bellebaum and Bock 2009). During the months of November and December, following harvest, the fields become open with 0.127-0.203 m long left out dry roots of paddy separated by an average distance of 0.254 m adjacentl (13.68 roots per m 2 ), acts as a maze.…”

Predation and nutrients drive population declines in breeding waders

“…). Decreasing populations of some wader species can be linked to poor survival of eggs and young (Beintema and Müskens , Bellebaum and Bock , Kleijn et al. ), which differs from survival of adults that has been stable for decades (Roodbergen et al.…”

“…, Calladine et al. ), and nest predation is likewise a severe problem for waders living inland (Hötker and Segebade , Bellebaum and Bock , van de Pol et al. , Thorup and Koffijberg ).…”

“…Nest predation varies enormously among years, sites and populations (Teunissen et al. , Bellebaum and Bock , Thorup and Koffijberg ). This raises the question of why there is so much variation in predation among years within a single site, and which are the factors accounting for such variation?…”