Trade-offs between age-related breeding improvement and survival senescence in highly polygynous elephant seals: Dominant males always do better.

摘要: Life history trade-off theory predicts that current reproduction can negatively affect survival and future reproduction. Few studies have assessed breeding costs for males of polygynous species compared to females, despite substantial variation in success among individual (e.g. subordinate cf. dominant breeders). Specifically, differentiating between the cost attending seasons, additional successfully securing mating females is lacking. We investigated whether trade-offs are present highly male southern elephant seal (Mirounga leonina) using 34-years individual-level data. compare age-specific survival, recruitment probabilities pre-breeders (males yet recruit) breeders (subordinate social ranks) multievent models. Pre-breeders overlapping ages had similar probabilities, suggesting there was no attendance early recruits. In addition, probability recruiting as a breeder never exceeded same age. Therefore, older delayed generally did not improve their (probability being dominant) at more than younger Rather, age may be function quality, with lower quality individuals requiring time socially mature. When comparing breeders, we found clear evidence senescence, having higher baseline mortality. contrast, t + 1) increased age, maintaining subsequent breeders. The opposite trends both indicate lifetime, population-level trade-off. However, suggest consecutively (and accumulated cost) accelerated rate senescence when were previously subordinate. Thus, experienced actuarial regardless rank, possibly high quality) showing reduced success. make several novel contributions understanding life histories demography.