Tuft size matters: the effects of adult visual social experience on female mate preferences in a wolf spider

Abstract

While females may benefit from being selective when choosing a mate, social experience can result in variation in mate preferences. Few studies, however, have investigated how multiple factors of the social environment (e.g., male phenotype and social demography) may interact to affect mating preferences. We used the brush-legged wolf spider, Schizocosa ocreata, to determine whether female visual preference for males with large tufts (foreleg bristles) varies based on adult social experience. Video playback was used to simulate social conditions during the early adult stage (1–6 days post-maturity) to test the effects on subsequent mating preferences (day 7 post-maturity) in a multifactorial design. Females were presented a variable number of males (one or three) that varied in their phenotype (small or large tufts) at a variable encounter rate (once every other day or twice per day). On day 7, females were presented a small-tufted and a large-tufted male in a two-choice design. The number of receptivity displays towards each male were counted, and statistical models were used to determine whether the encounter rate, the number of males, or male phenotype best predicted female selectivity. The male phenotype (small or large tufts) that females previously experienced best predicted subsequent female selectivity, such that female S. ocreata exhibited more receptivity displays towards “familiar” males. This study demonstrates the importance of the social environment in the mate preferences of an invertebrate and encourages future studies to use multi-factorial experimental designs to determine the relative importance of social parameters. While our understanding of behavioral plasticity in mating behaviors of invertebrates has increased within the past decade, many researchers have used univariate approaches in such studies. This paper uses a multifactorial approach to investigate plasticity in female preferences of a wolf spider and is perhaps the first to manipulate three different parameters of the perceived social environment. In brief, we found that the “attractiveness” of the males that females previously saw affected subsequent mate preferences more than how often they saw males or how many males they saw per encounter. We also highlight a significant interaction between two variables that would not have been discovered using a univariate approach. Our paper should elicit interest from general behavioral ecologists, but perhaps more specifically those interested in the social environment, sexual selection, behavioral plasticity, video playback, and invertebrate biologists.