Bibliothèque Tour du Valat

Se connecter

Mot de passe oublié ?
Pas encore inscrit ?

La Tour du Valat

Institut de recherche pour la conservation des zones humides méditerranéennes

Détail

Ajouter au panier

Ajouter au panier

Lien vers la notice

Titre :	The Swedish Sea Eagle Project
Auteurs :	Bjorn Helander, Auteur
Type de document :	Article
Dans :	Dansk Ornitologisk Forenings Tidsskrift (92(4) 1998)
Article en page(s) :	342-346
Langues:	Anglais
Résumé :	The White-tailed Eagle Haliaeetus albicilla was fairly common in Sweden until the early or mid 19th century. but was subsequently brought close to extinction by persecution. When legal protection was enforced in 1924, a few tens of breeding pairs (bp) remained on the Baltic coast and in northern Sweden (Lapland). The Baltic population recovered slowly and reached about 100 bp in the 1950s. An alarming decrease in reproductive success was first noticed in the early 1960s. Retrospective studies have revealed that the deterioration in breeding success started already 10 years before that. The cause has proved to be the heavy contamination with organochlorine pollutants. Surveys of the breeding population 1964-1970 showed a further drop in breeding success. This led to the start of Project Sea Eagle in 1971. The project combines research and management activities with the overall purpose to ensure the long-term survival of the sea eagle in Sweden. A large-scale winter-feeding programme was organized from 1971. The feeding resulted in a marked increase in juvenile survival, which fully compensated for the poor reproduction - the population stabilized. An improvement in reproductive ability has been observed from the early 1980s leading to an annual increase in the number of bp in 1987-1996 of about 7%. A re-colonization is now under way of both coastal and freshwater habitats from where the sea eagle has been absent as a breeding species for a century or more. The population in Swedish Lapland has not been strongly affected by pollutants. This population appears to be isolated from the Baltic population. A slow increase in the number of hp also in Lapland is probably a result of the winter-feeding programme. In 1996, 68 out of 112 checked hp on the coast reproduced successfully (61%). At least 6 hp failed as a result of human disturbance and 4 after nests broke down: 1 bp was persecuted. In Lapland 22 out of 36 checked bp were successful (61%), whereas 10 out of 19 checked bp at "new" freshwater localities reproduced successfully (53%). Since the reproductive rate of the Baltic population has improved substantially during the last 5 years, in increase of the breeding population at an even higher rate than that observed to date can be expected, as fledglings from recent years mature (around the age of 5). This presupposes, though, that the enhanced survival, resulting from the supplemental feeding during winter, can be maintained.

FAQ

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

A-
A
A+