Complex interactions between temperature, sexual signals and mate choice in a desert-dwelling jumping spider

Environmental context is a crucial factor that influences sexual communication systems. Particularly in ectotherms, which cannot metabolically regulate their body temperature, temperature has an outsized effect on these intraspecific interactions. Using the desert-dwelling jumping spider Habronattus clypeatus, we assessed how temperature impacts various parts of the male signal and female mate choice for the signal. These spiders have multimodal, temporally structured courtship displays that begin with visual-only ‘sidling’ displays and proceed to multimodal visual and vibratory displays. To examine temperature effects, we performed sequential choice mating experiments (N = 45 trials) at two temperature treatments: hot (∼50 °C) and room temperature (∼25 °C). We found first that variation in the different stages of courtship segregated onto different principal components. The only aspect of male courtship that females expressed preference for was sidling courtship, but only at the higher temperature. Females also preferred to mate with heavier males at all temperatures. Specifically, females preferred to mate with males that performed shorter sidling displays. This is reflected by shorter copulation times in the warm treatment as well. We also found that temperature impacted only vibratory courtship and not sidling courtship. Our results highlight the importance of understanding environmental context in studies of animal communication. We also stress how a holistic, rather than reductive, approach to complex communication systems is vital in order to understand how selection acts upon them.