Data from: Foraging offsets declining fitness: Evidence of behavioral compensation for reproductive senescence

Animals face declining fitness contributions near the end of life, termed
reproductive senescence. Though reproductive senescence frequently stems
from energetic inefficiencies, animals making their final attempts at
reproduction have the greatest incentive to succeed, raising the question
of whether this deterioration is inevitable or if they can compensate to
maximize fitness. Here, we disentangled two components of lifetime fitness
—energy acquisition and allocation —and examined whether foraging effort
serves as behavioral compensation for reproductive senescence in female
mule deer (Odocoileus hemionus). For senescing animals, foraging effort
positively influenced newborn size, providing evidence of compensation for
declining fitness contributions. Moreover, we detected a likely diversion
of resources away from survival and to reproduction. Facing their final
opportunities to reproduce, animals adjusted their behavior to compensate
for reproductive senescence but not to support survival. By evaluating the
role of behavior in fitness, we reveal processes underlying senescence and
its alleviation in wild populations.