In this NWO-VIDI project we examine how the pervasive impact of avian migrant predators on intertidal communities may connect ecosystems on a global scale.
In the current biodiversity decline, predators are often the first to disappear. Predators are thought to play a positive role in biodiversity maintenance as they prevent certain prey species in achieving dominance, relaxing resource competition among prey, hence promoting prey growth rates, prey coexistence and diversity. Losses of species at the highest trophic levels in communities may therefore cause extinctions and shifts in size structure at lower trophic levels. However, this role of predators is still often underappreciated, largely because many ecosystems have already lost their top-predators and/or human-induced disturbances now blur the positive predation effects. Most of all, the role of migrant predators structuring communities along their migratory route has mostly been neglected.
Aiming to fill this knowledge gap, we study the role of molluscivore shorebirds for intertidal benthic communities, with a focus on the pristine and uninhabited Banc d’Arguin (Mauritania). On their way to and from Mauritania, these shorebirds (re)fuel in the Dutch Wadden Sea, an area that has lost much of its value due to human disturbance (notably bottom-disturbing fisheries). Therefore, molluscivore shorebird numbers are on the decline, both in the Wadden Sea and in West-Africa, and we are investigating whether the benthic community changes observed at Banc d’Arguin may in fact represent ‘spatial knock-on effects’ of human disturbance in the Wadden Sea. Recently, in parallel with the project in Mauritania, a project on crustacean-eating crab plovers in Barr al Hikman (Oman) has started.