Genetic estimates of annual reproductive success in male brown bears: the effects of body size, age, internal relatedness and population density.

摘要: 1. We studied male yearly reproductive success (YRS) and its determinants (phenotypic characteristics, age, population density) in two Scandinavian brown bear populations, using molecular techniques to determine paternity. 2. found a significant difference YRS between the study areas, with lower south than north. 3. In general, older larger males had higher YRS. Older may be more experienced competition for reproduction (male dominance). Large body size is of direct benefit male-male advantage endurance access females. 4. Age was relatively important north south, due perhaps differences age structure illegal killing. A single old dominated during study, which resulted most probably importance even structure, no able dominate, resulting intense among males, as deciding factor. 5. Male correlated positively density. This related expanding population, female densities declining towards edge. 6. Internal relatedness, measure genetic heterozygosity, negatively YRS, suggesting that outbred individuals have Individual heterozygosity at key or many loci reflect physical qualities condition-sensitive traits, directly contest sperm competition.