Skip to main content
Dryad

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

Levine, Rebecca1; Wagler, Brittany1; Rafferty, Rebekah1; Smiley, Rachel1; Jakopak, Rhiannon1; Randall, Jill2; Fieseler, Troy2; Scurlock, Brandon2; Monteith, Kevin1; LaSharr, Tayler3

Published Mar 18, 2026 on Dryad. https://doi.org/10.5061/dryad.sxksn03ht

Data files

Mar 18, 2026 version files 243.21 KB

Click names to download individual files

Abstract

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.