Adult Survival and Imperfect Assessment of Parentage: Effects on Male Parenting Decisions

Applications of molecular methods to assess parentage have revealed that the distribution of reproductive success among individuals often differs, sometimes dramatically, from expectation based on observation of behavioral association. Much theory exists on whether and when males should reduce parental care in response to level of paternity. Life-history theory predicts that trade-offs in reproductive effort should be influenced by adult survival. We used a dynamic programming approach to address how level of paternity, ability to assess paternity, and adult survival rate interact to affect male tolerance of reduced parentage in a given brood. Adult survival has the greatest influence on male decisions such that, for any given cost of reproduction and value of male care, tolerance of extrapair fertilizations (EPFs) decreases as adult survival increases. An unexpected result of these models is that an optimal response also depends on a male's ability to predict probability of parentage (i.e., uncertainty). These models better characterize the nature of paternity uncertainty and its effect on EPF tolerance than have previous models and add to our understanding of the complex relationship between uncertainty, mating strategies, and adult survival.