Winter consumption of the introduced Green Crab Carcinus maenas by Kelp Gulls Larus dominicanus

Abstract

The introduction of species can have negative effects on species, communities, and ecosystems, although native predators may profit from the introduced prey. We present an evaluation of the consumption of the introduced Green Crab (Carcinus maenas) by Kelp Gulls (Larus dominicanus) during the austral winter in Patagonia, Argentina. Green Crab remains were present in 9.4% (n = 416) of the Kelp Gull pellets collected between June and August of 2021, at four coastal sectors distributed along more than 400 km of coastline. Frequency of occurrence of Green Crabs in Kelp Gull pellets varied between 0 and 66.7% depending on the location, and being similar for the three studied months. Overall, Kelp gulls included at least 35 food items in their diet with variable contributions from different food categories, again depending on the location. This is the first report on the winter consumption of Green Crabs by Kelp Gulls and provides baseline information for understanding the role of this introduced species in newly invaded coastal ecosystems.