Park K, Hurley MM & Hudson PJ (2002) Territorial status and survival in red grouse Lagopus lagopus scoticus: hope for the doomed surplus?. Journal of Avian Biology, 33 (1), pp. 56-62. https://doi.org/10.1034/j.1600-048X.2002.330109.x
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.
red grouse; territoriality; survival; Red grouse Territoriality (Zoology) Scotland; Animal populations Red grouse Scotland
Journal of Avian Biology: Volume 33, Issue 1