The potential costs to copulation
have been established relatively well.
The sea slug sheds 1/3 of the internal penis length after each copulation
Halffter (1997) proposed that when the sperm of a new copulation
are pulled inwards this pushes the sperm from previous copulations
deeper into the closed branch of the spermatheca.
The low number of copulations
with younger females may be related to the small amount of pheromone released by them, as was observed in studies carried out by Foster et al.
These included time of day, size of male and female, presence or absence of brooding eggs, number of chelae, position of mating crabs, shelter usage, duration of copulation
, and postcopulatory guarding.
Egg size was not related to number of copulations
(P < 0.
The patterns of sperm precedence, the increased frequency of starting and stopping copulation
with less actual time spent in copula of second males, suggests that the second males could not successfully copulate.
chaudoiri, including the same four phases of pre-mating struggle, copulation
, PCA and post-mating struggle.
Extramarital and pair copulations
in the cattle egret.
Pairing with a female confers at least two benefits for males at the spawning grounds: copulation
success and an "owner advantage" in fights.
The regression of the number of offspring sired against the number of copulations
was significant and revealed that 103.
these males are known to sever their own genitals in an attempt to plug the female, thereby gaining paternity advantage by preventing other males from mating with her.