La Tour du Valat

Institut de recherche pour la conservation des zones humides méditerranéennes

Titre :	Territorial status and survival in red grouse Lagopus lagopus scoticus: hope for the doomed surplus?
Auteurs :	K. J. Park, Auteur ; M. M. Hurley, Auteur ; P. J. Hudson, Auteur
Type de document :	Article
Dans :	Journal of Avian Biology (33(1) MAR 2002)
Article en page(s) :	56-62
Langues:	Anglais
Résumé :	A previous study of survival in territorial and non-territorial red grouse Lagopus lagopus scoticus conducted between 1957 and 1967 found that territorial status in the autumn pre-determined over-winter survival. A very high proportion of territorial birds survived and virtually all non-territorial birds died or emigrated. We tested the hypothesis that over-winter survival was dependent on territorial status within four grouse populations in Scotland between 1986 and 1993. In contrast to the previous study, 66% of non-territorial birds survived over winter compared to approximately 70% of territorial birds. There was no significant effect of territorial status on the survival estimates. Moreover, some of the birds considered to be non-territorial during autumn went on to successfully raise a brood. We suggest that on our study sites, territory ownership in autumn did not greatly influence over-winter survival, and territorial behaviour did not determine breeding density as previously supposed. We postulate differences with other studies may reflect variations in scale and predation pressure.

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