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 :	[Breeding population of Lapwing Vanellus vanellus in northern Westphalia, Germany, in 1999 compared to 1972/73 and 1989/90]
Auteurs :	Immogen Bluehdorn, Auteur
Type de document :	Article
Dans :	Vogelwelt (Die) (122(1) 2001)
Article en page(s) :	15-28
Résumé :	In 1999 a grid-type survey was conducted in an area of 1825 km2 to estimate the number of breeding Lapwings in a part of the northern Muensterland, Northrhine-Westphalia, NW Germany. The results were compared with those of similar surveys in 1972/73 and 1989/90. In April and May two censuses were carried out by ten observers. Individuals seen were mapped (scale 1:25,000), and for a third of the study area agricultural land-use was recorded. A grid cell (2.06 km2 each) was called occupied if at least two adult individuals were seen. The number of breeding pairs was calculated by dividing the number of all Lapwings in half. During the course of the 1999 breeding season the number of occupied grid cells decreased from 41% to 37%. Compared to 1972/73, when 63% of the cells of the were occupied, there was a significant decrease in occupied cells. The mean number of breeding pairs per km2 was 1.03 in April 1999 and 0.89 in May, whereas in 1989/90 0.57 pairs bred per km2. From 1972/73 to 1989/90 25% of the occupied grid cells were abandoned while 10% were newly occupied. From 1989/90 to 1999 a further 22% of the examined grid cells were abandoned and 13% were newly occupied. Half of the occupied grid cells contained 1-3 breeding pairs. In 1999 compared to 1989/90 more grid cells were occupied by more than 3 pairs. In line with the seasonal state of agricultural land-use, in April most lapwings were seen on stubble-fields and freshly tilled fields, in later spring they mostly occupied maize fields. Half of the Lapwings seen in grassland in May had chicks. The decreased number of occupied grid cells since 1972/73 is explained by loss of suitable breeding habitats. However, the number of breeding lapwings seems to have stabilised on a low level in the last ten years. The decreased number of occupied grid cells and the slight rise in the number of breeding pairs reflect a concentration of breeding lapwings in the remaining suitable habitats. Insufficient breeding success possibly led to changes in the state of occupation of some grid cells.

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+