The barnacle goose is possibly the species that gives a touch of the wild to Djurgården. Many passers-by stop to admire the orderly and cackling flocks which fly back and forth between the patches of short grass on Djurgården. They have their favourite breeding place on the Fjäderholm islands. That this arctic species of goose thrives so well is thanks to Skansen; only some of the free-range geese had their wings clipped and so an unintentional relocation outside of Skansen became a fact. Both parent birds raise the young, which is an advantage when shielding them from crows and gulls which can quickly destroy a clutch of ducklings which only have a lone female as protection. The geese are gregarious by nature and can be aggressive even to humans if they come too close to their young. However, on Södra Djurgården the goose droppings are considered a nuisance to Park visitors. Attempts have been made to estimate the size of the population on the Fjäderholm islands. As many as 235 individual nests of breeding birds were counted there in 2008.