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 :	Reproductive output, population structure and cyclic dynamics in Capercaillie, Black Grouse and Hazel Grouse
Auteurs :	J. Lindstrom, Auteur ; E. Ranta, Auteur ; M. Linden, Auteur ; H. Linden, Auteur
Type de document :	Article
Dans :	Journal of Avian Biology (28(1) MAR 1997)
Article en page(s) :	1-8
Langues:	Anglais
Résumé :	We studied annual changes in the reproductive output of cyclic populations of Capercaillie Tetrao urogallus, Black Grouse Tetrao tetrix- and Hazel Grouse Bonasa bonasia in Finland. The data consisted of route censuses made in early autumn in 11 provinces during 1964-1984. Records separated adults and young of the year. First, young bird numbers were regressed against adult densities. On a natural logarithmic scale this relationship was linear. No differences in slope of the regression were detected among the 11 provinces within any of the species. The regression slopes for the three species were: Capercaillie 1.24, Black Grouse 0.91 and Hazel Grouse 0.87. The reproductive output was defined as the residuals of the species-specific regression models in each province. It correlated with the population cycle, so that high reproductive output preceded high total numbers the next year. Using a simple stage-structured transition matrix model with delayed, second-order density dependence in breeding success, and differential fecundity and survival between first-time breeders and older birds, we were able to create cyclic population fluctuations closely matching those documented for Finnish grouse.

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+