Natural foraging of the dogwhelk, Nucella lapillus (Linnaeus); the weather and whether to feed

The natural cycle of foraging and sheltering in dogwhelks is closely associated with changing weather conditions. The behaviour of individual dogwhelks was quantified over three, approximately 40 day, periods on the rocky shores of Llanddwyn Island, Anglesey. Dogwhelks were monitored in a range of habitats, from sheltered, high shore, barnacle covered substrata to wave exposed, low shore, mussel covered substrata. The proportion of dogwhelks either foraging or sheltering varied greatly from day to day, indicating similarity of behaviour among individuals within each population. In sheltered areas, foraging was limited during periods of sunny and warm weather. In exposed areas, however, foraging was restricted during periods of strong wave action. Most dogwhelks in exposed areas foraged in periods of calm, warm and sunny weather.Transplanted dogwhelks appeared initially to be more active foragers than non-transplanted, control, animals in both exposed and sheltered areas. After about 10 days, however, the transplants began to behave in a similar way to the controls.