Doctor of Philosophy, The Ohio State University, 2022, Evolution, Ecology and Organismal Biology

Many animals live in a heterogeneous landscape of predation, with consequences that include changes in behavior, morphology, and physiology. While we understand much about how predation directly impacts prey phenotypes, our understanding of its indirect effects on the phenotypic attributes of prey are quickly becoming a subject of intense study. It has been shown that merely the risk of predation could alter the behavioral phenotype of prey, which in turn, could influence their reproductive fitness. Thus, the behavioral phenotypes in the parental generation are a potential target for natural selection. Because such traits are often heritable, predation risk could indirectly shape the phenotype of subsequent generations of prey through genetic change. Prior work has focused on the ability of organisms to evolve or alter the expression of traits (phenotypic plasticity) in response to environmental changes. Yet, there is now copious evidence that demonstrates how the environment can induce non-genetic phenotypic changes that span multiple generations. Such ‘transgenerational plasticity' occurs when the environment experienced by parents alters the phenotypes of subsequent generations. Transgenerational responses have been documented in many organisms for a variety of environmental factors and are postulated to have far-reaching consequences for population dynamics, community interactions and the rate and direction of evolutionary change. Nonetheless, despite widespread attention on the existence of transgenerational plasticity, our understanding of how behavior can be altered transgenerationally in responses to predation risk in the parental generation remains limited. My research has sought to test the hypothesis that predation risk in the maternal environment can drive transgenerational behavioral plasticity through maternal effects. I used an intraguild predator-prey system consisting of two wolf spiders. Tigrosa helluo served as the predator, with Schizocosa ocr (open full item for complete abstract)

Committee: Susan Gershman (Advisor); Stuart Ludsin (Committee Co-Chair); Ian Hamilton (Committee Member) Subjects: Behavioral Sciences; Biology; Ecology

PhD, University of Cincinnati, 2015, Arts and Sciences: Biological Sciences

Studies have revealed that in many animals, females use various male traits in mate choice to assess a male's ability to provide direct and/or indirect benefits. While it is easy to assume that females should always prefer to mate with males with these traits, increasing evidence suggests that females demonstrate plasticity in their mating preferences based on intrinsic and extrinsic factors. This dissertation focuses on how variation in the social environment results in variation in the mating preferences of the brush-legged wolf spider, Schizocosa ocreata. I used video and vibratory playback to simulate variation in the social environment of juvenile female S. ocreata and measure how that affects adult mate preferences. First, female S. ocreata were provided experience during their penultimate instar stage, manipulating the number of courting males per encounter (one or three males) and the encounter rate (every other day or twice per day). When given a choice between a lower quality (small-tufted) and higher quality (large-tufted) male in their adulthood, females were increasingly more selective depending on exposure to cumulatively more mature males during their penultimate social experience. Second, females were provided varying social experience with courting males of various tuft sizes during their penultimate instar stage. In both no-choice and two-choice designs, adult females were more receptive towards small-tufted and large-tufted males, respectively, if they saw small-tufted or large-tufted males during their penultimate stage. Third, female S. ocreata were provided variable sensory experience during their penultimate stage. Specifically, females in this study were provided playback of male courtship using vibratory signals, visual signals, multimodal signals, or no experience at all. When measured for unimodal preferences in no-choice presentations as adults, females demonstrated more receptivity displays towards the `familiar' signal modality. Two add (open full item for complete abstract)

Committee: George Uetz Ph.D. (Committee Chair); Ann Rypstra Ph.D. (Committee Member); John Layne Ph.D. (Committee Member); Stephen Matter Ph.D. (Committee Member); Michal Polak Ph.D. (Committee Member) Subjects: Biology

Doctor of Philosophy, The Ohio State University, 2015, Evolution, Ecology and Organismal Biology

Communication between potential mates is of vital importance to the fitness of many taxa, allowing individuals to find one another, as well convey and receive information important in assessing a suitable mate. Signals involved in sexual communication can be transmitted through visual, vibrational and chemical modalities, with chemical communication being the oldest and most widespread. The ability to detect visual and vibrational cues often occurs across a range of inputs, while chemical communication has the potential for much higher specificity, as only those receivers possessing chemosensory cells attuned to the compounds used will be able to detect their presence. The detection and integration of multimodal signals into a behavioral response has been extensively studied in the Schizocosa ocreata (Hentz 1844) wolf spider (Lycosidae) model system. In this ground dwelling species, males respond to substrates containing female chemical signals with visual and vibratory courtship displays. While this response has been well characterized, the chemical identity of these signaling compounds is currently unknown, and pheromone identity has been understudied across spiders as a whole. The behavioral response of male S. ocreata to conspecific chemical signals has primarily been studied in the context of substrate bound female cues, though past studies have suggested that chemicals produced by conspecific male competitors may inhibit male courtship behavior, and have even suggested a role for olfaction.We further examined the role olfaction plays in male detection and location of females, and while we found no evidence that males are utilizing olfaction to find mates, we did observe behavioral changes to conspecifics of both sexes, and a reduction of activity in the presence of volatile cues from a predator. At levels of competitor cues that males are expected to encounter in nature, we found no evidence that male-male inhibition occurs in this species. In examining male r (open full item for complete abstract)

Committee: J. Andrew Roberts (Advisor); Susan Gershman (Committee Member); Roman Lanno (Committee Member) Subjects: Behavioral Sciences; Biology; Ecology

MS, University of Cincinnati, 2007, Arts and Sciences : Biological Sciences

Coercive (forced) mating has evolved in many animal species because it likely increases male fitness. Coercive male mating behavior is uncommon in spiders, as females are larger and potentially cannibalistic. In Schizocosa ocreata (Hentz) wolf spiders, females usually respond to male courtship with receptivity, although males sometimes force unreceptive females to copulate. Multivariate analysis of mating trials revealed distinct behavior patterns (e.g., aggressive male behavior; female resistance) allowing designation as coercive vs. cooperative. Males were also observed to use fangs during coercive mating, resulting in hemolymph loss and scarring in females (not seen in unmated females, and less frequent in other matings). Experimental immobilization of male fangs resulted in no significant difference in mating success, but reduced copulation duration compared to controls. The frequency of coercion in this species (11.7% of matings) suggests a possible alternative male behavioral tactic in response to female resistance.

Committee: Dr. George Uetz (Advisor) Subjects: