Abstract: | Sibling red grouse resembled each other and their parents in social dominance rank and in an aggressiveness score. This was shown by comparisons of variance within and among clutches, correlations between parents and offspring, and experiments involving selection. Both dominance and aggressiveness scores were inherited. There was weak evidence that a laying hen's nutrition and crowding might also influence the dominance of her offspring. These results indicate mechanisms that may underlie fluctuations in the numbers of wild red grouse. |