Table 1.
Descriptive statistics of relevant life history traits along time.
Table 2.
The degrees of data completeness for the response variables investigated.
Figure 1.
Changes in the studied traits in response to maternal age at first reproduction from the 1880s to 1970s.
A, offspring quantity (O-quantity); B, offspring survival rate at age 15 (O-survival); C, offspring breeding probability (O-breeding); D, maternal reproductive success (M-LRS); E, maternal risk of breeding failure (M-RBF). Time/decade is shown at the top. When there was a significant difference between the social classes, “o” denotes lower class mothers and “|” denotes non-lower (middle or upper) class mothers; when there was no difference, only one symbol (+) is used. Offspring breeding probability and maternal reproductive success data are not yet available for mothers giving first birth in the 1960s and 1970s.
Figure 2.
Changes in the studied traits in response to maternal fertility from the 1880s to the 1970s.
A, offspring survival rate at age 15 (O-survival); B, offspring breeding probability (O-breeding); C, maternal reproductive success (M-LRS); D, maternal risk of breeding failure (M-RBF). Time/decade is shown at the top. Abscissa of each discrete point represents an integer number of children, i.e. maternal fertility. When there was a significant difference between the social classes, “o” denotes lower class mothers and “|” denotes non-lower (middle or upper) class mothers; when there was no difference, only one symbol (+) is used. Offspring breeding probability and maternal reproductive success data are not yet available for mothers giving first birth in the 1960s and 1970s.