Data from: Elevated temperatures have sex-specific effects on nuptial gift behavior

Increasing developmental temperatures are well-known to impact fertility,
yet their effects on pre-copulatory behaviors, despite having clear
fitness consequences, are often overlooked. In many species, male nuptial
gift presentation during courtship plays an important role in sex-specific
mate choice, fitness, and subsequent co-evolutionary dynamics. However,
developmental temperature effects on nuptial gift behaviors and their
implications for population fitness remain unknown. Heat-induced changes
to male behavior may signal fertility, driving female discrimination,
particularly in monandrous systems where exclusively pairing with an
infertile male threatens population growth. Additionally, as nuptial gift
production is costly, the differential allocation hypothesis suggests
males should adjust gift investment based on female fitness. Here, we
investigated how elevated developmental temperature affects nuptial gift
behavior, mating likelihood, and reproductive output in the monandrous
species Drosophila subobscura. Individuals developed at either a control
or stressful temperature, and fully factorial no-choice mating tests were
used to identify sex-specific effects of heat stress. Heat-stressed males
were largely infertile, less likely to mate, present a gift, or have a
gift accepted, suggesting nuptial gifts may signal male fertility and
influence female mate choice. Heat-stressed females were also less likely
to mate, receive a gift, and were presented with fewer gifts from
heat-stressed males. As heat-stressed females required more gifts to match
the reproductive output of controls, selection may drive male mate choice
through strategic resource allocation. These findings highlight how
climate change may significantly impact sex-specific mate choice, with
important implications for selection on pre-copulatory courtship traits
and population dynamics.