can be classified into several combinations.
occurs when a male and female pair
only with one another during a breeding season.
can be divided into
mating systems involve multiple males and females.
may be a female
against sperm-borne disease.
(PTM) predicts that
rather than on
Many birds once thought to be
, may exhibit some
promiscuity: individuals form pair bonds but engage in
In some species, males compete for access to eggs via
where females store sperm from multiple matings, and sperm from different males compete to fertilizable eggs.
In primates, sperm competition may lead to larger
sperm competition leads to last male
The competition involves a
in individual sperm, and also plays a role in the diversity of
Sperm competition may even be correlated with sperm