Data from: Effects of past mating behavior versus past ejaculation on male mate choice and male attractiveness

Past reproductive effort allows males to assess their ability to acquire
mates, but it also consumes resources that can reduce their future
competitive ability. Few studies have examined how a male’s reproductive
history affects his subsequent mate choice; and, to date, no study has
determined the relative contribution of past mating behavior and past
ejaculate production because these two forms of investment are naturally
highly correlated. Here, we disentangled the relative effects of past
mating behavior and past ejaculate production in male mosquitofish
(Gambusia holbrooki) by experimentally preventing some males from
ejaculating when trying to mate. We assessed the effect of mating behavior
on mate choice by comparing males that had previously been with or without
access to females and male rivals for 16 weeks; and assessed the effect of
ejaculation on mate choice by comparing males that either could or could
not ejaculate when they had access to females for 16 weeks. We compared
(1) time females spent with each male, (2) total distance males swam, (3)
total time males spent inspecting females, (4) proportion of time males
spent with the solitary females in separate models, with age (week 8, week
16) and treatment of reproductive history ("naive male",
"mating only male" and "mating and ejaculation males")
as fixed factors.  We showed that reproductive history did not
affect male attractiveness, but it did affect male mate choice. Somewhat
surprisingly, in two-choice trials males from all three treatments
preferred females in the vicinity of a rival over solitary females. This
preference was marginally stronger for males engaging in previous mating
behavior but was unaffected by past ejaculate production. This is the
first study to quantify the relative influence of pre- and post-copulatory
reproductive investment on male mate choice.