Long-term effects of sons in bighorn sheep

The file contains longitudinal data collected on female bighorn sheep at Ram Mountain, Alberta, Canada.
Explanation of the different columns:
id = female identifier
year = year of observation
reproductive_success = whether or not a female produced a lamb surviving to 1 year of age
fecundity = evidence of lactation (1 = yes, 0 = no)
lamb_summer_survival = offspring survival to weaning (1 = yes, 0 = no)
lamb_winter_survival = offspring survival from weaning to 1 year of age (1 = yes, 0 = no)
Lamb_sex = lamb sex (0 = female, 1 = male)
previous_reproductive_status = female reproductive status in preceding year (0 = failed, 1 = weaned a female, 2 = weaned a male).
Longevity = standardized female longevity in years
Age = standardized female age in years
Density = standardized population size in June of the year of observation
early_Nlamb = standardized number of offspring weaned by a female between 2 and 7 years of age
early_sexratio = standardized proportion of sons weaned by a female between 2 and 7 years of age