Fig. 1.

Females’ “grandmaternal” success through sons, based on the percentage of 21 infants sired. Excludes one infant sired by an old male (IV, >30 y) whose mother was unlikely to be alive and therefore not among the females sampled. Bars are the mothers of potential sires in this study; asterisks indicate mothers who had died before their grandoffspring were conceived (Table S2). Segmented bars represent the percent of offspring sired by different sons. Thus, BS gained the same number of grandoffspring from her only son as DD, TZ, and NY gained from the two to three of their sons that sired offspring. Numbers of resident adult sons and daughters, respectively, are noted in brackets for each mother. Hatched segments indicate offspring sired by six males whose mothers had previously maintained unusually strong spatial associations with them (26).