Rüdiger Riesch

Reproductive traits are central to organismal fitness, and so the factors influencing patterns of reproduction and offspring survival are at the heart of biology. Making use of breeding data collected over 16 years at the King Khalid Wildlife Research Centre in Saudi Arabia, we investigated the reproductive biology of Arabian gazelles Gazella arabica. Offspring survival was mainly a function of birth weight, with heavier offspring having higher survival rates than lighter offspring. However, while sons were heavier than daughters, daughters had higher survival rates. We could not find evidence that giving birth to sons negatively impacts offspring weight in the following year. We uncovered large narrow-sense heritability (h2) in offspring weight at birth, while maternal effects (m2) on birth weight were of lesser importance. However, maternal effects on offspring survival were strong until weaning age, while paternal effects dominated survival to sexual maturity and first reproduction. We propose that variation in maternal postnatal care might overshadow the effects of maternal inheritance of birth weights, while the overall strong heritability of weight at birth and the paternal effects on survival illustrates strong variance in sire fitness based on genetic quality, suggesting a role for sexual selection by female mate choice in wild populations.