In the late seventies Cormorants were rare in Roskilde Fjord but in 1986 a pair appeared in the heron colony at Askehoved in Bognæs forest. During the following years the colony tripled in size annually, reaching 650 pairs in 1992. The rapid growth has now come to an end and the number has varied from 700 to 800 pairs.

Cormorants winter in central Europe and are already here at the end of March but the establishment of the colony takes a very long time and the last young do not leave the colony until August.

They often forage a long way from the colony, in Køge bay and Isefjord as well as in nearby lakes. An analysis of the otoliths from the fish eaten by Cormorants, which are found in their pellets, gives a good picture of the Cormorant´s diet. The Cormorants in Roskilde Fjord are remarkable for their relatively high consumption of eels, but it is surprising that about 10% (by weight) of their food consists of stickle-back. This is in accord with the general principal that the cormorant´s choice of food reflects the food available in the area.




Wherever it appears the cormorant is a controversial bird because it is in competition with fishermen and because its droppings damage the trees it nests in.