Résumé
Exploitation by humans affects the size and structure of populations. This
has evolutionary and demographic consequences that have typically being
studied independent of one another. We here applied a framework recently
developed applying quantitative tools from population ecology and
selection gradient analysis to quantify the selection on a quantitative
trait - birth date - through its association with multiple fitness
components. From the long-term monitoring (22 years) of a wild boar (Sus
scrofa scrofa) population subject to markedly increasing hunting pressure,
we found that birth dates have advanced by up to 12 days throughout the
study period. During the period of low hunting pressure, there was no
detectable selection. However, during the period of high hunting pressure,
the selection gradient linking breeding probability in the first year of
life to birth date was negative, supporting current life history theory
predicting selection for early births to reproduce within the first year
of life with increasing adult mortality.