photo: Rienk Fokkema

Fokkema, R. W., van der Velde, E., Stessens, M., Bos, D., Belfín, O., de Jong, M. E., Hooijmeijer, J. C. E. W., & Piersma, T. (2024). Mapping mammalian meadow bird nest predators in a Dutch dairy farming landscape. European Journal of Wildlife Research, 70, 122.

What species lurk in the dark, unseen by human eyes, and prey upon the nests and chicks of meadow birds at night? Many researchers, conservationists or volunteers will know the feeling, suddenly eggs are gone or destroyed or fields teeming with birds alarming and calling to their chicks have become silent. The causes behind this loss of eggs and chicks are thought to be manifold and interacting, but one factor at play is predation. We know very little of the underlying factors cascading into high predation rates of meadow bird nests or chicks, but also of the actual ecology of the predators themselves. Luckily, technology can help us out and motion-activated infrared camera traps allow us to monitor at times when the average ecologist is fast asleep. We deployed a camera network across our study area in Southwest Friesland to map the presence of night-active predators. Simultaneously, we deployed camera traps at the nests of black-tailed godwits (Limosa limosa limosa; hereafter called godwit) to follow their fate and document the identity of possible nest predators. We did this during three springs; 2021 to 2023. Using our camera network, we uncovered a community of different mammalian predators, consisting of 11 different species. Six species occurred most frequent: the domestic cat (Felis catus), brown rat (Rattus norvegicus), red fox (Vulpes vulpes), European badger (Meles meles), beech marten (Martes foina) and the European polecat (Mustela putorius). These six focal species formed the basis of our analyses. We detected marked and relatively stable differences in the spatial occurrence of these six species over our study area. Foxes and badgers had a noted positive co-occurrence, whereas other species had a less strong, but negative co-occurrence, such as the domestic cat and the red fox. Over all three study years, red foxes were the most consistent predator of godwit nests (see Figure), whereas domestic cats and brown rats predated relatively few nests but were abundantly present in the agricultural landscape. In general, we conclude that the presence of predator species by itself is not a good indicator of whether the species will be an important predator of meadow bird nests. Our study also provided possible evidence for compensatory nest predation: when beech marten nest predation diminished over the years, nest predation by red foxes increased. This underscores that in evaluating predation of meadow birds, and potential measures taken to mitigate them, one should take the full community of predator species in the agricultural landscape into account. Our study forms an important step in understanding the intricate relationship between meadow birds such as godwits and the community of predators. Next up is further understanding how features of the agricultural landscape can influence predator occurrence and affect meadow bird breeding success.