| Titre : | Danmarks fugle gennem to århundreder / Trends in the Danish bird fauna since 1800 (2021) |
| Auteurs : | Hans Meltofte, Auteur ; Lars Dinesen, Auteur ; David Boertmann, Auteur ; Poul Hald-Mortensen, Auteur |
| Type de document : | Article |
| Dans : | Dansk Ornitologisk Forenings Tidsskrift (115(1) 2021) |
| Article en page(s) : | 184 |
| Langues: | Anglais |
| Mots-clés : | Danemark ; Aves ; Dynamique population ; Histoire ; paysage |
| Résumé : |
If we look at the breeding birds in the Danish landscape types, it must be assumed that bird species associated with trees and shrubs in woods, gardens and scattered vegetation are very likely to have become many times more numerous over the last 200 years. This is primarily true of the number of individuals, but the number of species has also increased. Many populations have been reduced to a few percent of what they were in the early 1800s, and a number of bird species associated with open habitats have disappeared or are on the verge of doing so . However, since the densities of breeding birds in woods and other areas with trees and shrubs are many times higher than the densities on open land, currently we probably have more breeding birds in Denmark than 100200 years ago – although there has been a negative trend in recent decades .
Many species associated with wetlands have been in sharp decline, although nature restoration during recent decades has meant improved habitats and more birds in the particular areas concerned. On the other hand, primarily as a result of reduced hunting and other persecution, the number of breed ing bird species and individuals of birds associated with wet lands have also increased over the last half century or more. Several species of swans, ducks and geese are thus probably more numerous today than at any earlier time since year 1800. The populations of many breeding coastal birds were close to national extirmination around the year 1900 due to over exploitation , but most of them have subsequently recovered greatly as a result of more restrictive hunting legislation and more sanctuaries. Nowadays most birds are found in wooded country as well as in areas with scattered trees and shrubs, whereas in the 1800s by far the majority of birds were found in open country. The highest number of breeding bird species occur in freshwater and brackish water wetlands as well as in woods. These landscape types each support more than twice as many species as any other landscape type. In the case of staging migrants and winter guests, hunting meant that the populations of many species were greatly re duced until the mid1900s. Subsequently, a number of species recovered significantly in line with more restrictive hunting laws and more shooting free reserves not only in Denmark but also in other countries along the flyways . Some species benefited from an increased supply of nutri ents to the aquatic environment during the 20th century – until eutrophication in many places resulted in aquatic plant death and oxygen depletion. The development towards a more Atlantic climate in Denmark since the middle of the 19th century has contributed to changes in many breeding bird populations, including disappearance of some species and immigration of others. At the same time, phenology and winter distribution has changed in many species. |
| En ligne : | https://pub.dof.dk/publikationer/433 |
Exemplaires (2)
| Code-barres | Cote | Support | Localisation | Section | Disponibilité |
|---|---|---|---|---|---|
| 16357 | 22205 | Numéro spécial | Bibliothèque | Pdoc | Disponible |
| 16358 | 3A/ | Périodique | Bibliothèque | Périodiques étagère 3 | Disponible |
