| Titre : | Numbers of Common Gulls Larus canus and Black-headed Gulls Chroicocephalus ridibundus in Denmark during winter 2010/2011 and 2011/2012 |
| Auteurs : | Hans Meltofte, Auteur |
| Type de document : | Article |
| Dans : | Dansk Ornitologisk Forenings Tidsskrift (108(4) 2014) |
| Article en page(s) : | 226-231 |
| Langues: | Anglais |
| Résumé : | During the Christmas and New Year holidays 2010/11, the Danish Ornithological Society organized a census to improve our knowledge on the numbers and use of communal night-time roosts of wintering Common and Black-headed Gulls in Denmark. As early as Christmas, the winter had become severe with extensive ice cover on lakes and fjords, and therefore the census was repeated the following year, when the winter was mild.The totals of individuals recorded appear in Tab. 1 and the distributions of birds at night roosts and daytime occurrences are shown on the maps in Fig. 2 and 3. More than 71/2 and 21/2 times as many Common Gulls and Black-headed Gulls, respectively, were recorded in the mild winter 2011/12 compared to the severe winter the year before (Tab. 1).30% of Common Gulls and 46% of Black-headed Gulls were recorded on communal night-time roosts in 2010/11, while the corresponding ratios for 2011/12 were 74% of Common Gulls and 56% of Black-headed Gulls (cf. Tab. 1).Due to uncertainty about the geographical coverage of the census, I dare not estimate the totals of the two species of gull wintering in Denmark, but rough estimates suggest that at least 10% and 2%, respectively, of the European mid-winter populations of Common and Black-headed Gulls are present in Denmark in mild winters. According to the 1%-criterion, at least six sites qualify as sites of international importance for Common Gulls, while no sites qualify for Black-headed Gulls. |
Bibliothèque Tour du Valat
Se connecter
La Tour du Valat
Institut de recherche pour la conservation des zones humides méditerranéennes- Les publications récentes de la Tour du Valat
- Catalogue en ligne du centre de ressources
- A la une
-
Sélections
- Les écrits de Luc Hoffmann, fondateur de la Tour du Valat
- Des références récentes sur les zones humides méditerranéennes
- Quelques exemples d'impact du changement climatique sur les zones humides
- Quelques références bibliographiques sur la grippe aviaire
- Les recherches de la Tour du Valat sur le saturnisme
- De récentes publications sur la Camargue
- Le fonds Camargue de la bibliothèque
- Coordination géographique
- Nous contacter
Infos pratiques
Heures d'ouverture et contact
Lundi , mardi et jeudi de 9h à 12h et de 13h à 17h00 : ouverture au public ...
Liens utiles
- 1 - Le site Internet de la Fondation Tour du Valat
- 2 - La base documentaire du Pôle-relais lagunes méditerranéennes
- 3 - Le site Internet consacré aux Oiseaux d'eau en région Méditerranée
- 4 - Le site Internet ObsNature Camargue -Crau-Alpilles - recueil de données d'observations naturalistes
- 5 - Le site Internet de MedWet, l’initiative pour les zones humides méditerranéennes
