Figure 4.

Number of grandoffspring attributed to female North American red squirrels (n = 284) as a function of the female's average litter bias score over her lifetime. Litter bias scores were calculated as the difference between the adult sex ratio (proportion male) within a given year and the sex ratio (proportion male) of an individual litter. The difference was assigned a positive value if the litter sex ratio was biased towards the rare sex in the adult population, and assigned a negative value if biased towards the common sex.