Cautious versus desperado males: predation risk affects courtship intensity but not female choice in a wolf spider

Abstract

Understanding the decisions that animals make in the presence of predation risk can reveal their assessment of current and future reproductive options. The wolf spider, Pardosa milvina, has a conspicuous courtship display that is an indicator of male quality. In an initial experiment, we determined that male courtship was highly repeatable and correlated with symmetry. We then used symmetry as an indicator of quality to explore the reactions of males when presented with simulated predation risk and an attractive virgin female. There were no differences in courtship features between risk and no risk treatments unless we took into account male quality. High-quality males reduced courtship intensity under risk conditions suggesting that they estimated their long-term fitness prospects as strong. This response is consistent with the asset protection principle, which suggests that animals with high value traits should behave cautiously. Low-quality males courted at high levels under predation risk, which seemed to be reckless attempts to attract females. This response is analogous to the effect, which is one explanation for vigorous fighting by inferior animals in contests. Although females used behavior to select males when no predator information was present, they seemed to use symmetry in the presence of predator cues. The ability of females to select the most attractive males suggests that they can accurately assess male quality under laboratory conditions. High courting desperado males may occasionally be selected in more complex environments and/or when they are in competition with other males.