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Full-Text Articles in Life Sciences
Mate Sampling Behavior Determines The Density Dependence Of Sexual Selection, J. Colton Watts, Eileen A. Hebets, Brigitte Tenhumberg
Mate Sampling Behavior Determines The Density Dependence Of Sexual Selection, J. Colton Watts, Eileen A. Hebets, Brigitte Tenhumberg
School of Biological Sciences: Faculty Publications
Theory predicts that the strength of sexual selection (i.e., how well a trait predicts mating or fertilization success) should increase with population density, yet empirical support remains mixed. We explore how this discrepancy might reflect a disconnect between current theory and our understanding of the strategies individuals use to choose mates. We demonstrate that the density dependence of sexual selection predicted by previous theory arises from the assumption that individuals automatically sample more potential mates at higher densities. We provide an updated theoretical framework for the density dependence of sexual selection by (1) developing models that clarify the mechanisms through …
Sister Species Diverge In Modality-Specific Courtship Signal Form And Function, Eileen Hebets, Mitch Bern, Rowan H. Mcginley, Andy Roberts, Arik Kershenbaum, James Starrett, Jason E. Bond
Sister Species Diverge In Modality-Specific Courtship Signal Form And Function, Eileen Hebets, Mitch Bern, Rowan H. Mcginley, Andy Roberts, Arik Kershenbaum, James Starrett, Jason E. Bond
School of Biological Sciences: Faculty Publications
Understanding the relative importance of different sources of selection (e.g., the environment, social/sexual selection) on the divergence or convergence of reproductive communication can shed light on the origin, maintenance, or even disappearance of species boundaries. Using a multistep approach, we tested the hypothesis that two presumed sister species of wolf spider with overlapping ranges and microhabitat use, yet differing degrees of sexual dimorphism, have diverged in their reliance on modality- specific courtship signaling. We predicted that male Schizocosa crassipalpata (no ornamentation) rely predominantly on diet-dependent vibratory signaling for mating success. In contrast, we predicted that male S. bilineata (black foreleg …
Males And Females Evolve Riskier Traits In Populations With Eavesdropping Parasitoids, Oliver M. Beckers, William E. Wagner
Males And Females Evolve Riskier Traits In Populations With Eavesdropping Parasitoids, Oliver M. Beckers, William E. Wagner
School of Biological Sciences: Faculty Publications
Predation and/or parasitism often limits the evolution of conspicuous male traits and female preferences because conspicuous traits can attract predators or parasites and it is costly for females to associate with males that attract predators or parasites. As a result, males and females in high-risk populations are expected to evolve safer mating behaviors compared to individuals from low-risk populations. We tested this antagonistic selection hypothesis in the field cricket Gryllus lineaticeps. Males produce chirped songs, and both female crickets and the eavesdropping parasitoid fly Ormia ochracea prefer faster chirp rates. The flies attack the field crickets late in the …
The Maintenance Of Phenotypic Divergence Through Sexual Selection: An Experimental Study In Barn Swallows Hirundo Rustica, Rebecca Safran, Yoni Vortman, Brittany R. Jenkins, Joanna K. Hubbard, Matt Wilkins, Rachel J. Bradley, Arnon Lotem
The Maintenance Of Phenotypic Divergence Through Sexual Selection: An Experimental Study In Barn Swallows Hirundo Rustica, Rebecca Safran, Yoni Vortman, Brittany R. Jenkins, Joanna K. Hubbard, Matt Wilkins, Rachel J. Bradley, Arnon Lotem
School of Biological Sciences: Faculty Publications
Previous studies have shown that sexual signals can rapidly diverge among closely related species. However, we lack experimental studies to demonstrate that differences in trait-associated reproductive performance maintain sexual trait differences between closely related populations, in support for a role of sexual selection in speciation. Populations of Northern Hemisphere distributed barn swallows Hirundo rustica are closely related, yet differ in two plumage-based traits: ventral color and length of the outermost tail feathers (streamers). Here we provide experimental evidence that manipulations of these traits result in different reproductive consequences in two subspecies of barn swallow: (H. r. erythrogaster in North …
Parasitoid Infestation Changes Female Mating Preferences, Oliver M. Beckers, William E. Wagner
Parasitoid Infestation Changes Female Mating Preferences, Oliver M. Beckers, William E. Wagner
School of Biological Sciences: Faculty Publications
Females often adjust their mating preference to environmental and social conditions. This plasticity of preference can be adaptive for females and can have important consequences for the evolution of male traits. While predation and parasitism are widespread, their effects on female preferences have rarely been investigated. Females of the cricket Gryllus lineaticeps are parasitized by the parasitoid fly Ormia ochracea. Infestation with fly larvae substantially reduces female life span and thus reproductive opportunities of the cricket. Both female G. lineaticeps and flies orient to male song and both prefer male songs with faster chirp rates to songs with slower chirp …
Tradeoffs Limit The Evolution Of Male Traits That Are Attractive To Females, William E. Wagner, Oliver M. Beckers, Amanda E. Tolle, Alexandra Basolo
Tradeoffs Limit The Evolution Of Male Traits That Are Attractive To Females, William E. Wagner, Oliver M. Beckers, Amanda E. Tolle, Alexandra Basolo
School of Biological Sciences: Faculty Publications
Tradeoffs occur between a variety of traits in a diversity of organisms, and these tradeoffs can have major effects on ecological and evolutionary processes. Far less is known, however, about tradeoffs between male traits that affect mate attraction than about tradeoffs between other types of traits. Previous results indicate that females of the variable field cricket, Gryllus lineaticeps, prefer male songs with higher chirp rates and longer chirp durations. In the current study, we tested the hypothesis that a tradeoff between these traits affects the evolution of male song. The two traits were negatively correlated among full-sibling families, consistent with …
Eavesdropping Parasitoids Do Not Cause The Evolution Of Less Conspicuous Signaling Behavior In A Field Cricket, Oliver M. Beckers, William E. Wagner
Eavesdropping Parasitoids Do Not Cause The Evolution Of Less Conspicuous Signaling Behavior In A Field Cricket, Oliver M. Beckers, William E. Wagner
School of Biological Sciences: Faculty Publications
Males of many species produce conspicuous mating signals to attract females, but these signals can also attract eavesdropping predators and parasites. Males are thus expected to evolve signaling behaviors that balance the sexual selection benefits and the natural selection costs. In the variable field cricket, Gryllus lineaticeps, males sing to attract females, but these songs also attract the lethal parasitoid fly Ormia ochracea. The flies use male crickets as hosts for their larvae, primarily search for hosts during a 2 h period following sunset and prefer the same song types as female crickets. We tested whether males from high-risk populations …
False Promises: Females Spurn Cheating Males In A Field Cricket, William E. Wagner, Andrew R. Smith, Alexandra Basolo
False Promises: Females Spurn Cheating Males In A Field Cricket, William E. Wagner, Andrew R. Smith, Alexandra Basolo
School of Biological Sciences: Faculty Publications
Females commonly prefer to mate with males that provide greater material benefits, which they often select using correlated male signals. When females select higher-benefit males based on correlated signals, however, males can potentially deceive females by producing exaggerated signals of benefit quality. The handicap mechanism can prevent lower-quality males from producing exaggerated signals, but cannot prevent cheating by higher-quality males that choose to withhold the benefit, and this poses a major problem for the evolution of female choice based on direct benefits. In a field cricket, Gryllus lineaticeps, females receive seminal fluid products from males with preferred songs that …
Testosterone And Group Size In Cliff Swallows: Testing The “Challenge Hypothesis” In A Colonial Bird, Linda C. Smith, Samrrah A. Raouf, Mary Bomberger Brown, John C. Wingfield, Charles R. Brown
Testosterone And Group Size In Cliff Swallows: Testing The “Challenge Hypothesis” In A Colonial Bird, Linda C. Smith, Samrrah A. Raouf, Mary Bomberger Brown, John C. Wingfield, Charles R. Brown
School of Biological Sciences: Faculty Publications
The “challenge hypothesis” states that increases in testosterone levels of male animals during the breeding season are directly related to the extent of intrasexual competition for resources or mates that they experience. Although often tested in territorial species, the challenge hypothesis has not been evaluated for colonial animals that live in groups of different sizes and that thus experience different intensities of intrasexual competition. We measured circulating testosterone levels of male and female cliff swallows (Petrochelidon pyrrhonota) in southwestern Nebraska, where these birds nest in colonies of widely different sizes. Males had significantly higher testosterone levels than females, …
Microsatellite Analysis Of Female Mating Behaviour In Lek-Breeding Sage Grouse, Katy Semple, Robert K. Wayne, Robert M. Gibson
Microsatellite Analysis Of Female Mating Behaviour In Lek-Breeding Sage Grouse, Katy Semple, Robert K. Wayne, Robert M. Gibson
School of Biological Sciences: Faculty Publications
We used microsatellite DNA markers to genotype chicks in 10 broods of lek-breeding sage grouse, Centrocercus urophasianus, whose mothers’ behaviour was studied by radio tracking and observing leks. Previous behavioural studies suggested that almost all matings are performed by territorial males on leks and that multiple mating is rare. Two broods (20%) were sired by more than one male. Genetic analyses of the broods of eight females that visited an intensively studied lek were consistent with behavioural observations. Four females observed mating produced singly sired broods and males other than the individual observed copulating were excluded as sires for most …
Evolutionary Change In A Receiver Bias: A Comparison Of Female Preference Functions, Alexandra Basolo
Evolutionary Change In A Receiver Bias: A Comparison Of Female Preference Functions, Alexandra Basolo
School of Biological Sciences: Faculty Publications
Female poeciliid fishes of the sister genera Xiphophorus and Priapella share a preference for males with swords, despite phylogenetic information suggesting that swords arose in Xiphophorus after the divergence of the two genera. This study examines the strength of sword and body-size preferences in a representative of both genera. A comparison of the preference functions reveals that the strength of the preference favoring a sword in P. olmecae is significantly stronger than that in X. helleri. This result demonstrates that the pre-existing bias is not evolutionarily fixed, and that there has been change in the bias favoring the sword, …
Female Choice In Sage Grouse: The Roles Of Attraction And Active Comparison, Robert M. Gibson
Female Choice In Sage Grouse: The Roles Of Attraction And Active Comparison, Robert M. Gibson
School of Biological Sciences: Faculty Publications
Previous studies of female choice in sage grouse Centrocercus urophasianus have implicated both the acoustic quality and repetition rate of the stereotyped strut display as putative cues for female choice. Stages in the choice process at which specific components of male courtship display influence female decisions were investigated using field observations of female premating behavior. Females visited a subset of territorial males and then actively chose one of these as a mate. The order in which males were visited suggested that females searched until an acceptable mate was found, rather than employing a “best-of-n” tactic. Numbers of females visiting a …