title: Male-mimicking females increase male-male interactions, and decrease male survival and condition in a female-polymorphic damselfly.
abstract: Biologists are still discovering diverse and powerful ways sexual conflicts shape biodiversity. The present study examines how the proportion of females in a population that exhibit male mimicry, a mating resistance trait, influences conspecific males' behavior, condition, and survival. Like most female-polymorphic damselflies, Ischnura ramburii harbors both "andromorph" females, which closely resemble males, and sexually dimorphic "gynomorph" counterparts. There is evidence that male mimicry helps andromorphs evade detection and harassment, but males can also learn to target locally prevalent morph(s) via prior mate encounters. I hypothesized that the presence of male mimics could therefore predispose males to mate recognition errors, and thereby increase rates of costly male-male interactions. Consistent with this hypothesis, male-male interaction rates were highest in mesocosms containing more andromorph (vs. gynomorph) females. Males in andromorph-biased mesocosms also had lower final body mass and higher mortality than males assigned to gynomorph-majority treatments. Male survival and body mass were each negatively affected by mesocosm density, and mortality data revealed a marginally significant interaction between andromorph frequency and population density. These findings suggest that, under sufficiently crowded conditions, female mating resistance traits such as male mimicry could have pronounced indirect effects on male behavior, condition, and survival.
authors.affiliation: Section of Integrative Biology, University of Texas at Austin, 1 University Station C0900 Austin, Texas, 78712.|Current Address: Department of Integrative Biology, W.K. Kellogg Biological Field Station, 3700 East Gull Lake Drive, Hickory Corners, Michigan, 49060.
authors.forename: Eben J
authors.initials: EJ
authors.lastname: Gering
mesh_terms: D000818:Animals; D005260:Female; D008297:Male; D063191:Odonata; D010641:Phenotype; D011156:Population Density; D012098:Reproduction; D012726:Sexual Behavior, Animal
keywords: Sexual conflict; female polymorphism; male-male interactions; population dynamics