Data and code from: The adaptive significance of polyandry: A meta-analysis

Polyandry is prevalent, but the optimal patterns of mating for females
remain poorly understood despite their importance for our understanding of
sexual selection. We therefore performed a meta-analysis on the female
fitness consequences of mating with multiple males. Across 166 studies
spanning 127 arthropod species, we found that mating with more males
generally enhanced female fecundity and reduced female lifespan. The net
fitness effects of polyandry, however, were small. Moreover, fecundity
benefits were not clearly detectable when females mated with more than two
males. Additionally, we found first that studies assessing partial as
opposed to lifetime fitness reported greater benefits of polyandry.
Second, protocols involving selection bias, where females were afforded
some control over mating rates, reported lower costs of polyandry compared
to studies without selection bias. Third, polyandry was reported as less
beneficial in experiments that involved continuous housing of females with
males. Finally, polyandry was more beneficial in species that transfer
nuptial gifts. We thus suggest that future polyandry studies aim to
measure lifetime fitness while also mitigating selection bias and exposure
of females to excessive harassment. Doing so will help us understand how
sexual selection operates in both sexes.