| Popis: |
Capsule: The Black Grouse is a primarily lekking species, but low population density and lack of suitable habitat can lead to the establishment of non-lekking populations.\ud \ud Aims: To understand if differences in density could be related to differences in the lekking system, if there were differences in lek-site selection, and if there was a direct effect of habitat on the lek size.\ud \ud Methods: We compared lek sizes between two Black Grouse populations with different male population densities as estimated by distance sampling. We considered land-cover categories, landscape metrics and orographic variables and computed the Ivlev’s Electivity Index to evaluate habitat selection of males in the two study areas. A general linear model was used to assess the relationship between lek size and habitat variables.\ud \ud Results: We could not demonstrate the direct effect of density on the displaying behaviour but we found strongly different patterns of lek-site selection and different effects of habitat on lek size according to the population density.\ud \ud Conclusions: We concluded that habitat normally considered as high quality and habitat complexity may play different roles in selection by solitary versus lekking males when different population densities are considered. |
