Abstract: Temperature affects ectotherms in a variety of ways. These effects can be especially complex in sexual behaviors, as different sexes may be affected differently by temperature. We examined this in the jumping spider, Habronattus clypeatus. In this species, males court females using visual and vibratory signals. We tested whether key intersexual behaviors would change with temperature in similar, predictable ways across males and females. We first measured temperature and apparent activity of individuals across the day. We found that H. clypeatus are active across a wide range of temperatures (11–56 °C) and are most active at times of day when temperature ranges from 13 to 46 °C. Next, we performed mating experiments across behaviorally relevant temperatures. Females were more likely to allow males to progress to later stages of courtship and had higher mating rates at higher temperatures. Male visual and vibratory courtship behaviors generally became faster, higher-pitched, and lower in amplitude at higher temperatures. This relationship between temperature and signal aspects attained a roughly curvilinear shape, with an asymptote around 40 °C. Intriguingly, mating rates in the lab were highest at temperatures potentially above those during peak spider activity in the field. Our results suggest that temperature’s effects on behavior are complex and can affect males and females differently. This work emphasizes that understanding temperature effects on mating is critical to understanding sexual selection patterns particularly in species which use complex signals. Significance statement: Temperature affects communication in most ectothermic species. Previous research has shown that temperature changes courter signals and chooser choice. However, this has never been investigated in species that use multimodal signals. We investigate how signals and choice change across temperatures in a desert-dwelling jumping spider. Using field temperature/activity modeling and a series of courtship experiments in the lab, we show that male signals and female choice change with temperature across biologically relevant ranges. Our results suggest that the temperatures at which mating is most likely occur at times of the day when animals are least active. These counterintuitive results highlight the importance of understanding how behavior in a controlled lab environment corresponds to natural field conditions as well as the importance of examining the effects of naturally occurring environmental variation on behavior.

Temperature is known to influence many aspects of organisms and is frequently linked to geographical species distributions. Despite the importance of a broad understanding of an animal's thermal biology, few studies incorporate more than one metric of thermal biology. Here we examined an elevational assemblage of Habronattus jumping spiders to measure different aspects of their thermal biology including thermal limits (CT_min, CT_max), thermal preference, V̇CO₂ as proxy for metabolic rate, locomotor behavior and warming tolerance. We used these data to test whether thermal biology helped explain how species were distributed across elevation. Habronattus had high CT_max values, which did not differ among species across the elevational gradient. The highest-elevation species had a lower CT_min than any other species. All species had a strong thermal preference around 37 °C. With respect to performance, one of the middle elevation species was significantly less temperature-sensitive in metabolic rate. Differences between species with respect to locomotion (jump distance) were likely driven by differences in mass, with no differences in thermal performance across elevation. We suggest that Habronattus distributions follow Brett's rule, a rule that predicts more geographical variation in cold tolerance than heat. Additionally, we suggest that physiological tolerances interact with biotic factors, particularly those related to courtship and mate choice to influence species distributions. Habronattus also had very high warming tolerance values (> 20 °C, on average). Taken together, these data suggest that Habronattus are resilient in the face of climate-change related shifts in temperature.