Data from: Polyandry and postcopulatory sexual selection in a wild population

When females mate multiply, postcopulatory sexual selection can occur via
sperm competition and cryptic female choice. Although postcopulatory
selection has the potential to be a major force in driving evolution, few
studies have estimated its strength in natural populations. Likewise,
though polyandry is widespread across taxa and is the focus of a growing
body of research, estimates of natural female mating rates are still
limited in number. Microsatellites can be used to estimate the number of
mates represented in females’ sperm stores and the number of sires
contributing to their offspring, enabling comparisons both of polyandry
and of two components of postcopulatory selection: the proportion of males
that mate but fail to sire offspring, and the degree of paternity skew
among the males that do sire offspring. Here we estimate the number of
mates and sires among wild females in the Hawaiian swordtail cricket
Laupala cerasina. We compare these estimates to the actual mating rates
and paternity shares we observed in a semi-natural population. Our results
show that postcopulatory sexual selection operates strongly in this
species: wild females mated with an average minimum of 3.6 males but used
the sperm from only 58% of them. Furthermore, among the males that did
sire offspring, paternity was significantly skewed. These patterns were
similar to those observed in the field enclosure, where females mated with
an average of 5.7 males and used the sperm from 62% of their mates, with
paternity significantly skewed among the sires.