Annual Measures Data Set Individual: prairie dog individual identity. Victims: total number of ground squirrels killed by female that year. Mass: female’s body mass when her (almost weaned) juveniles first appeared aboveground when they were about 5.5 weeks old. Age: female’s age (in years) that year. Clan size: number of adult (>1 year old) prairie dogs that lived in female’s home territory. Ward size: number of adult prairie dogs that lived in female’s home ward. Year rate: annual rate of aggression measured as the mean number of aggressive interactions per day for entire study-colony. Rate PDPD: estimate of individual aggressiveness to conspecifics measured as the mean number of aggressive interactions with other prairie dogs per day for each prairie dog female. Rate PDGS: estimate of individual aggressiveness to ground squirrels measured as the mean number of aggressive interactions with ground squirrels per day for each prairie dog female. Litter size: litter size when (almost weaned) offspring first appeared aboveground. Female surv: 0, female did not survive until the next mating season; 1, female did survive until the next mating season. Fitness: annual fitness measured as the sum of (a) the mother’s survivorship until the next mating season (0 or 1), and (b) 50% of her offspring that survived >11 months (range = 0-5). For all variables, a period indicates missing data. LRS Data Set Variables defined as in Annual Measures Data Set, and indicate mean annual values for a female across her lifetime, or for Victims, cumulative number of ground squirrels killed by female during her lifetime. LRS: total number of a female’s offspring that survived for >11 months (yearlings). Lifespan: total years female was known to have survived (present at study-colony).