Aarhus Universitets segl

No. 87: Denmark's breeding population of cormorants in 2016

Bregnballe, T. & Nitschke, M. 2016. Danmarks ynglebestand af skarver i 2016. Aarhus Universitet, DCE – Nationalt Center for Miljø og Energi, 36 s. - Teknisk rapport fra DCE - Nationalt Center for Miljø og Energi nr. 87. http://dce2.au.dk/pub/TR87.pdf




This report presents the results of the annual count of all apparently occupied Great Cormorant nests throughout Denmark. In 2016, a total of 31,682 nests was registered, only 324 nests more than in 2015, corresponding to an increase of 1.0 %. In Denmark as a whole, the Cormorant breeding population maintained stable numbers at around 39,000 pairs during 1993-2006, followed by a decline to around 26,400 pairs in 2010-2013 (Fig. 1).


In three out of seven regions there were substantial decreases in breeding numbers from 2015 to 2016, whereas numbers increased in three regions. Numbers decreased by 12 %, 17 % and 14 % in southwest Kattegat, the archipelago west and south of Funen and in northern Zealand respectively. The increases amounted to 20 % in southern Zealand and the large islands there, 11 % in Limfjorden and 14 % in the westernmost region including the fjords of western Jutland where the vast majority of breeders are found in Ringkøbing Fjord.


The total number of breeding colonies in Denmark increased from 73 in 2015 to 83 in 2016. The trend in earlier years of a gradual decrease in size of the largest colonies did not continue in 2016. The largest colony in 2016 was Stavns Fjord, on the island of Samsø in the southwestern part of Kattegat which held 2,155 nests.


The Danish Nature Agency, Ministry of the Environment implemented management measures to reduce breeding success at 10 colonies in 2016, and gave permission to private landowners to undertake management at another 9 colonies. In 2016, a total of 4,668 nests was subject to management. The eggs were sprayed with vegetable oil in 4,284 of the nests and the remaining nests were managed in other ways, primarily by removal. More nests were subject to management in 2016 than in 2010-2015, but fewer than during 2003-2009 (Fig. 3).