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No. 99: Breeding numbers of Great Cormorants Phalacrocorax carbo in the Western Palearctic, 2012-­2013

Bregnballe, T., Lynch, J., Parz-Gollner, R., Marion, L., Volponi, S., Paquet, J.-Y., David N. Carss & van Eerden, M.R. (eds.) 2014. Breeding numbers of Great Cormorants Phalacrocorax carbo in the Western Palearctic, 2012­2013. IUCN-Wetlands International Cormorant Research Group Report. - Scientific Report from DCE – Danish Centre for Environment and Energy No. 99, 224 pp. http://dce2.au.dk/pub/SR99.pdf

Summary

This report gives an overview of the size and distribution of the breeding population of Great Cormorants Phalacrocorax carbo in the Western Palearctic in 2012 as well as detailed descriptions of the status for the breeding populations in 38 of the areas (countries or parts of countries) included in the survey. The national and sub-national surveys were conducted in coordination with and facilitated by the project 'Cormorant counts in the Western Palearctic' lead by the IUCN/Wetlands International Cormorant Research Group and the European Commission project ‘CorMan’ contracted by Aarhus University, Denmark and the Centre for Ecology & Hydrology, United Kingdom. The counts project gave guidance on methods, developed web-based tools, collated details from the counts, compiled an overview at the Pan-European level and provided support during the writing up of national results.

Highest priority was given to ensure that all breeding colonies were counted in areas where the continental sub-species P. c.sinensis was breeding. Attention was also given to assess the size of the breeding populations in countries from where Great Cormorants migrate to EU Member States. To obtain information about recent trends in population development in different parts of Europe, comparisons were made with breeding numbers recorded during a similar Pan-European count in 2006.

The size of the breeding population of Great Cormorants in the Western Palearctic was estimated to be between 406,000 and 421,000 breeding pairs in 2012 (excluding some regions in Russia and the western part of Kazakhstan). It is estimated that around 42,500 breeding pairs belonged to the Atlantic sub-species P. c. carbo and around 371,000 to the continental sub-species P. c. sinensis. Approximately 294,000 pairs of the sinensis sub-species bred west of the western borders of Russia and Turkey (Kaliningrad and the Russian part of the Gulf of Finland included). Within this area the 28 EU Member States had 214,800 breeding pairs of the continental sub-species.

The species was recorded breeding in almost all the countries in Europe in 2012. While 50 % of all sinensis birds were breeding in large colonies with more than 1,000 nests, most breeding colonies had fewer than 100 nests. The largest colony was found in Ukraine and had 18,000 nests. Most other large colonies with more than 1,000 nests were found around the Baltic Sea, the Black Sea, the Sea of Azov, the Caspian Sea and in The Netherlands.

The 38 national or sub-national presentations of the current status refer to 2012 except for four countries where the descriptions refer to 2013 or to historical records of breeding. Each of these presentations includes descriptions of the total size and distribution of the breeding population and presents information about numbers and sizes of breeding colonies, as well as the extent of human intervention in them. Some of the descriptions also include information about trends in population development. Each of the national or sub-national presentations is introduced by a summary.

The following paragraphs describe the status of the breeding population in 2012 and the change in numbers from 2006 to 2012 within each of four major areas within the Western Palearctic:

The North-East Atlantic.This area includes most countries along the northeastern coasts of the Atlantic Ocean (countries that have coasts along the Baltic Sea are not included). The Atlantic sub-species P. c.carbo as well as the continental sub-species P. c.sinensis are breeding in this area.

The North-East Atlantic – P. c. carbo.Out of the 42,500 breeding pairs most bred along the coast of Norway (ca. 19,000 pairs). For the United Kingdom (UK) and France breeding numbers could not be determined with certainty because some of the colonies in these countries had both sub-species breeding, and the proportion of each sub-species was not known for all colonies. It was estimated that the UK had 6,500 breeding pairs along the coast and 955 pairs of the carbo sub-species in inland colonies, and the UK was thus the second most important breeding area for the Atlantic sub-species in Europe. France had 8,673 breeding pairs of which about 3,000 were estimated to be carbo birds. Iceland had 4,772 breeding pairs and the estimate for the coasts of Ireland was 4,366 pairs. It was further estimated that the Barents Sea and White Sea coasts had around 4,600 breeding pairs in 2012, but these estimates were uncertain due to incomplete coverage.

The data on trends indicated that breeding numbers of P. c. carbo had declined markedly in Norway, by around 11,000 pairs (-37 %) from 2006 to 2012. A declining trend was also recorded along the coast of the UK. Breeding numbers had either remained stable or increased in Iceland, the Barents Sea (the Russian Federation) and Ireland, as well as in France and in inland areas in the UK. 

The North-East Atlantic – P. c. sinensis.It was estimated that the continental sub-species had 36,900 breeding pairs in this area. The majority of these – 23,556 pairs –bred in The Netherlands where the highest densities were found around Lake IJsselmeer. France was the second most important breeding area – 5,700 breeding pairs estimated to belong to the sinensis sub-species. The other breeding areas included inland areas in the UK (estimated at 2,809 pairs), the southern coast of Norway (2,500 pairs), Spain (1,605 pairs) and Belgium (1,584 pairs). Great Cormorants were not breeding in Portugal, Luxembourg and Monaco in 2012.

Comparison with 2006 showed that noticeable increases had occurred in Spain (an increase of 1,300 pairs, 453 %), in inland areas in France (by 2,500 pairs, 62 %) and in southern Norway (by 1,100 pairs, 87 %). Numbers had remained unchanged in The Netherlands and Belgium.

The Baltic Sea – P. c. sinensis. This area covers the countries along the Baltic Sea and the Russian part of the Gulf of Finland and Kaliningrad. Total breeding numbers were 167,700 pairs, and this region constituted the most important breeding area in Europe for the continental sub-species. The highest numbers were recorded in Sweden (40,598 pairs), Denmark (27,237 pairs), Poland (26,600 pairs) and Germany (22,550 pairs). Together with The Netherlands, these countries constituted the core breeding area for the continental sub-species in Europe for more than 35 years. However, during and after the 1990s the breeding population expanded eastwards in the Baltic Sea.

The other countries around the Baltic Sea had the following breeding numbers in 2012: Finland (17,258 pairs), Estonia (13,000 pairs), Kaliningrad (9,535 pairs), the Russian part of the Gulf of Finland (4,605 pairs), Lithuania (3,200 pairs) and Latvia (3,106 pairs). The largest concentrations of breeders were found in association with the large and highly eutrophic lagoons in the southern Baltic, i.e. Vistula Lagoon, Odra Lagoon and the Curonian Lagoon.

Compared with 2006 breeding numbers had increased by 17,000 pairs (28 %) along the eastern coast of the Baltic Sea and decreased by 15,000 pairs (-19 %) in the western part of the Baltic Sea. The most marked increase was recorded in Finland (an increase of 11,500 pairs, 199 %), and the highest decrease was recorded in Denmark (a decline of 10,800 pairs, -28 %).

Central Europe and Mediterranean – P. c. sinensis. The area includes the countries in central Europe and in the central and eastern Mediterranean. The total numbers of breeders were 20,839 pairs, of which 40 % were found in only four colonies. The largest colony had 4,730 nests and was located at Kerkini Lake in northern Greece. The three other large colonies had 1,000-1,200 nests and were found in FYRO Macedonia, Montenegro and Italy.

At the national level, Greece had the highest number of breeding pairs (6,978 pairs), followed by Italy (3,914 pairs) and Hungary (2,700 pairs). The five other countries that had more than 1,000 breeding pairs were Switzerland (1,037 pairs), Croatia (1,331 pairs), Serbia (1,900-2,100 pairs), Montenegro (1,156 pairs) and FYRO Macedonia (1,130 pairs). The lowest numbers of breeders were recorded in the Czech Republic (297 pairs), Bosnia-Herzegovina (171 pairs), Slovakia (99 pairs) and Austria (65 pairs). Great Cormorants were not recorded breeding in Slovenia, Kosovo and Albania in 2012.

From 2006 to 2012 noticeable increases were recorded in Greece (by 2,400 pairs, 53 %), Italy (by 1,800 pairs, 83 %), Serbia (by 1,100 pairs, 113 %) and Switzerland (by 800 pairs, 385 %). Declines between 2006 and 2012 were recorded in Montenegro (by 850 pairs, -42 %), Croatia (by 830 pairs, -38 %) and Hungary (by 540 pairs, -17 %).

Black Sea and Sea of Azov – P. c. sinensis. This area includes Belarus, the countries that border the Black Sea and several Russian regions between the Sea of Azov and the Caspian Sea as well as Georgia, Azerbaijan and Armenia. Some parts of this area were not well covered during the survey, and in some cases estimates were thus based on older data.

It is estimated that this area had between 138,000 and 153,300 breeding pairs in 2012. The most important breeding areas were the Danube Delta, the Ukrainian coast of the Black Sea, the coasts of the Sea of Azov and the Volga Delta in the northwest end of the Caspian Sea. The vast majority of breeders were found in colonies with >1,000 nests.

At the national level, the Russian areas between the Sea of Azov and the Caspian Sea had the highest number of breeding pairs (60-68,000 pairs), followed by Ukraine (46,500 pairs) and Romania (13-15,000 pairs). Other countries with more than 2,000 breeding pairs were Turkey (6,500-8,500 pairs), Georgia (4,000-6,000 pairs), Belarus (3,250 pairs) and Bulgaria (2,775 pairs). Lower breeding numbers were estimated for Azerbaijan (1,000-2,000 pairs) and Moldova (700-1,500 pairs). Armenia had 10 breeding pairs.

From 2006 to 2012 numbers declined markedly in the north-western area of the Black Sea (the Danube Delta in Romania and Ukraine as well as the Ukrainian coasts of the Black Sea and the Sea of Azov): from 84,200 pairs in 2006 to 49,200 pairs in 2012 (-42 %). In the Danube Delta alone breeding numbers declined by 11,100 pairs (-51 %). Increases from 2006 to 2012 were reported in both Belarus (by 1,100 pairs, 52 %) and Bulgaria (by 790 pairs, 39 %). Breeding numbers had also increased in the Russian areas between the Sea of Azov and the Caspian Sea but the extent of increase could not be estimated with certainty.