TY - GEN A1 - Bierbach, David A1 - Schulte, Matthias A1 - Herrmann, Nina A1 - Tobler, Michael A1 - Stadler, Stefan A1 - Jung, Christian T. A1 - Kunkel, Benjamin A1 - Riesch, Rüdiger A1 - Klaus, Sebastian A1 - Ziege, Madlen A1 - Indy, Jeane Rimber A1 - Arias-Rodriguez, Lenin A1 - Plath, Martin T1 - Predator-induced changes of female mating preferences BT - innate and experiential effects T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Background In many species males face a higher predation risk than females because males display elaborate traits that evolved under sexual selection, which may attract not only females but also predators. Females are, therefore, predicted to avoid such conspicuous males under predation risk. The present study was designed to investigate predator-induced changes of female mating preferences in Atlantic mollies (Poecilia mexicana). Males of this species show a pronounced polymorphism in body size and coloration, and females prefer large, colorful males in the absence of predators. Results In dichotomous choice tests predator-naïve (lab-reared) females altered their initial preference for larger males in the presence of the cichlid Cichlasoma salvini, a natural predator of P. mexicana, and preferred small males instead. This effect was considerably weaker when females were confronted visually with the non-piscivorous cichlid Vieja bifasciata or the introduced non-piscivorous Nile tilapia (Oreochromis niloticus). In contrast, predator experienced (wild-caught) females did not respond to the same extent to the presence of a predator, most likely due to a learned ability to evaluate their predators' motivation to prey. Conclusions Our study highlights that (a) predatory fish can have a profound influence on the expression of mating preferences of their prey (thus potentially affecting the strength of sexual selection), and females may alter their mate choice behavior strategically to reduce their own exposure to predators. (b) Prey species can evolve visual predator recognition mechanisms and alter their mate choice only when a natural predator is present. (c) Finally, experiential effects can play an important role, and prey species may learn to evaluate the motivational state of their predators. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 984 KW - sexual selection KW - female choice KW - non-independent mate choice KW - predator recognition KW - Poecilia mexicana Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-431099 SN - 1866-8372 IS - 984 ER - TY - JOUR A1 - Nahavandi, Nahid A1 - Plath, Martin A1 - Tiedemann, Ralph A1 - Mirzajani, Ali R. T1 - Sexual and natural selection on morphological traits in a marine amphipod, Pontogammarus maeoticus (Sowinsky, 1894) JF - Marine biology research N2 - Sexual selection often leads to sexual dimorphism, where secondary sexual traits are more expressed in the male sex. This may be due, for example, to increased fighting or mate-guarding abilities of males expressing those traits. We investigated sexually dimorphic traits in four populations of a marine amphipod, Pontogammarus maeoticus (Gammaridea: Pontogammaridae), the most abundant amphipod species in the sublittoral zone along the southern shoreline of the Caspian Sea. Male amphipods are typically larger in body size than females, and have relatively larger posterior gnathopods and antennae. However, it remains to be studied for most other body appendages whether or not, and to what extent, they are sexually dimorphic. Using Analysis of Covariance (ANCOVA), we compared the relationships between body size and trait expression for 35 metric characters between males and females, and among the four populations examined by performing three different Discriminant Function Analyses (DFA). We detected several thus far undescribed sexual dimorphic traits such as the seventh peraeopods or the epimeral plates. We also found that the size of the propodus of the first and second gnathopods increases with increasing body size, and this allometric increase was stronger in males than in females. Finally, we found that the degree of sexual dimorphism in the expression of the width of the third epimeral plate varies across sites, suggesting that differences in ecology might affect the strength of sexual selection in different populations. KW - Caspian Sea KW - crustacean KW - dimorphism KW - scramble competition Y1 - 2011 U6 - https://doi.org/10.1080/17451001003713589 SN - 1745-1000 VL - 7 IS - 2 SP - 135 EP - 146 PB - Taylor & Francis Group CY - Oslo ER - TY - JOUR A1 - McCoy, Ellen A1 - Syska, Norbert A1 - Plath, Martin A1 - Schlupp, Ingo A1 - Riesch, Rüdiger T1 - Mustached males in a tropical poeciliid fish - emerging female preference selects for a novel male trait JF - Behavioral ecology and sociobiology N2 - One possible mechanism for the (co-)evolution of seemingly novel male traits and female preferences for them is that males exploit pre-existing female biases, and livebearing fishes (Poeciliidae) have been at the forefront of this research for almost two decades. Here, using 13 poeciliid species from four different genera, we tested whether mustache-like rostral filaments found in males of some Mexican molly (Poecilia sphenops) populations could have evolved due to exploitation of a pre-existing female bias. While Mexican mollies were the only species with a significant female association preference for mustached males, we also did not find any species exhibiting significant aversion for mustached males; rather, variance in female preference scores was large throughout. For example, more than 25% of females spent twice as much time with the mustached male compared to the non-mustached male in most species, but even 31% of Mexican molly females spent more time near the non-mustached male. Hence, a comparison of the strength of preference was inconclusive. We discuss the possibility that the female preference of P. sphenops for mustached males could be due to a female pre-existing bias (sensu lato), even if population means were not significant for species other than P. sphenops. This highlights the importance of distinguishing between population means and individual preferences when interpreting mate choice, and thus, adds depth to the concept of mating preferences as a motor for evolutionary change. KW - Female choice KW - Mate preferences KW - Pre-existing bias KW - Sexual selection KW - Character mapping Y1 - 2011 U6 - https://doi.org/10.1007/s00265-011-1154-x SN - 0340-5443 VL - 65 IS - 7 SP - 1437 EP - 1445 PB - Springer CY - New York ER - TY - JOUR A1 - Itonaga, Naomi A1 - Köppen, Ulrich A1 - Plath, Martin A1 - Wallschläger, Hans-Dieter T1 - Declines in breeding site fidelity in an increasing population of White Storks Ciconia ciconia JF - IBIS N2 - Following a steep decline, White Stork Ciconia ciconia populations in Germany are currently increasing, allowing us to examine potential density-dependent effects on breeding dispersal. Our data suggest that the proportion of breeding dispersers has increased over time, indicating a density-dependent component in nest-site fidelity that may be linked to increased competition. KW - age-dependent dispersal KW - density-dependent dispersal KW - population dynamics Y1 - 2011 SN - 0019-1019 VL - 153 IS - 3 SP - 636 EP - 639 PB - Wiley-Blackwell CY - Malden ER - TY - JOUR A1 - Bierbach, David A1 - Schulte, Matthias A1 - Herrmann, Nina A1 - Tobler, Michael A1 - Stadler, Stefan A1 - Jung, Christian T. A1 - Kunkel, Benjamin A1 - Riesch, Rüdiger A1 - Klaus, Sebastian A1 - Ziege, Madlen A1 - Rimber Indy, Jeane A1 - Arias-Rodriguez, Lenin A1 - Plath, Martin T1 - Predator-induced changes of female mating preferences innate and experiential effects JF - BMC evolutionary biology N2 - Background: In many species males face a higher predation risk than females because males display elaborate traits that evolved under sexual selection, which may attract not only females but also predators. Females are, therefore, predicted to avoid such conspicuous males under predation risk. The present study was designed to investigate predator-induced changes of female mating preferences in Atlantic mollies (Poecilia mexicana). Males of this species show a pronounced polymorphism in body size and coloration, and females prefer large, colorful males in the absence of predators. Results: In dichotomous choice tests predator-naive (lab-reared) females altered their initial preference for larger males in the presence of the cichlid Cichlasoma salvini, a natural predator of P. mexicana, and preferred small males instead. This effect was considerably weaker when females were confronted visually with the non-piscivorous cichlid Vieja bifasciata or the introduced non-piscivorous Nile tilapia (Oreochromis niloticus). In contrast, predator experienced (wild-caught) females did not respond to the same extent to the presence of a predator, most likely due to a learned ability to evaluate their predators' motivation to prey. Conclusions: Our study highlights that (a) predatory fish can have a profound influence on the expression of mating preferences of their prey (thus potentially affecting the strength of sexual selection), and females may alter their mate choice behavior strategically to reduce their own exposure to predators. (b) Prey species can evolve visual predator recognition mechanisms and alter their mate choice only when a natural predator is present. (c) Finally, experiential effects can play an important role, and prey species may learn to evaluate the motivational state of their predators. KW - Sexual selection KW - female choice KW - non-independent mate choice KW - predator recognition KW - Poecilia mexicana Y1 - 2011 U6 - https://doi.org/10.1186/1471-2148-11-190 SN - 1471-2148 VL - 11 IS - 3-4 PB - BioMed Central CY - London ER - TY - JOUR A1 - Bierbach, David A1 - Kronmarck, Claudia A1 - Hennige-Schulz, Carmen A1 - Stadler, Stefan A1 - Plath, Martin T1 - Sperm competition risk affects male mate choice copying JF - Behavioral ecology and sociobiology N2 - Mate choice copying was mostly described as a strategy employed by females to assess the quality of potential mates, but also males can copy other males' mate choice. An open question in this context is whether and how copying males evaluate sperm competition risk, as mating with a female that has already copulated with another male obviously sets the stage for intense sperm competition (i.e., in species with internal fertilization). Using the livebearing Atlantic molly (Poecilia mexicana) as a model, we asked (a) whether males of that species indeed copy other males' choices, and if they do so, (b) whether copying males strategically adjust their behavior to sperm competition risk. We used an approach where focal males could first choose to associate with a large or a small stimulus female. Mate choice tests were then repeated after an "observation phase" during which either no model male was present (treatment 1, control) or the previously non-preferred female could be seen associating (treatment 2) or physically interacting (treatment 3) with a model male. We found that, after the observation phase, males spent considerably more time with the previously non-preferred female in treatment (2), i.e., they copied the model male's choice. This effect was much weaker during treatment (3) where sexual interactions between the model male and the formerly non-preferred female were allowed. Males, therefore, seem to adjust their copying behavior strategically to the perceived risk of sperm competition. KW - Communication networks KW - Mate choice copying KW - Non-independent mate choice KW - Sperm competition KW - Social environment Y1 - 2011 U6 - https://doi.org/10.1007/s00265-011-1177-3 SN - 0340-5443 VL - 65 IS - 9 SP - 1699 EP - 1707 PB - Springer CY - New York ER -