Sex differences in behavior and functional traits are often attributed to differences in mating effort intensity, but the role of sex-specific parental demands remains poorly understood. Using the jumping spider Toxeus maxillosus-where males engage in mate searching and courtship without providing parental care, while females provide extended maternal care from egg attendance to offspring maturity (around 3 months)-we conducted an exploratory investigation into whether these distinct selective pressures led to divergence in spatial behaviors and nest architecture. Results revealed that males and females showed equivalent accuracy, latency, and learning-related performance in both a route-planning test under water stress and a color-pattern associative memory task. In contrast, during nest-construction assays, females built complex, multi-entrance structures that closely matched the container's corner geometry, whereas males constructed only simple nests. Moreover, females built significantly larger and denser nests in both tube-present and tube-absent conditions. These findings indicate that when spatial or signal-processing abilities are equally critical for both sexes' survival and reproduction, sexual and parental selection can converge on similar phenotypic performance; however, when trait functionality is strongly sex-limited (as in nest construction), divergence emerges. Our results reconcile conflicting reports of sex differences in spatially related traits by demonstrating that ecological necessity, rather than selective pressures alone, predicts the extent of divergence.
Wang et al. (Mon,) studied this question.