Aarhus Universitets segl

No. 125: Denmark's breeding stock of Great Cormorant in 2018

Bregnballe, T. & Sterup, J. 2018. Danmarks ynglebestand af skarver i 2018. Aarhus Universitet, DCE – Nationalt Center for Miljø og Energi, 40 s. - Teknisk rapport nr. 125. http://dce2.au.dk/pub/TR125.pdf

Summary

This report presents the results of the annual count of all apparently occupied Great Cormorant nests throughout Denmark. In 2018, a total of 31,605 nests were registered, which is 1,581 nests less than in 2017, corresponding to a decrease of 4.8%. In Denmark as a whole, the Cormorant breeding population peaked at around 40,000 pairs during 1996-2005, followed by a decline to around 26,400 pairs in 2010-2013. During 2014-2018, the population has been rather stable with around 31,700 pairs and annual fluctuations below 5%.

In the central parts of Denmark (around SW Kattegat, Funen and North Zealand), the population of Cormorants increased in 2018, whereas a decline was found in West Jutland and Southeast Denmark.

Denmark had eight colonies with more than 1,000 pairs in 2018 with the largest colony, located in Stavns Fjord on the island of Samsø, holding 2,422 nests.  The total number of breeding colonies in Denmark decreased from 80 in 2017 to 76 in 2018.

The Danish Nature Agency, Ministry of the Environment, implemented management measures to reduce breeding success in nine colonies in 2018 and gave permission to private landowners to undertake management in another eight colonies. In 2018, a total of 4,249 nests were subjected to management, mainly by preventing the eggs from hatching (e.g. by spraying them with vegetable oil). The proportion of nests exposed to management was approximately as in 2016 and 2017. In 2010-2015, fewer nests were subjected to management measures.