DOI: 10.5061/dryad.221mv
title: Data from: Trade-offs in female signal apparency to males offer alternative anti-harassment strategies for color polymorphic females

description: Color polymorphisms are known to influence receiver behavior, but how they
 affect a receiver's ability to detect and recognize individuals in
 nature is usually unknown. I hypothesized that polymorphic female
 damselflies represent an evolutionary stable strategy, maintained by
 trade-offs between the relative apparency of morphs to male receivers.
 Using field experiments on Enallagma hageni and focal studies of E. hageni
 and E. boreale, I tested for the first time the predictions that 1) green
 heteromorphs and blue andromorphs gain differential protection from sexual
 harassment via background crypsis and sexual mimicry respectively, and 2)
 female morphs behaviorally optimize their signal apparency to
 mate-searching males. First, based on male reactions elicited by females,
 against a high contrast background the two morphs did not differ in being
 detected by males and once detected, did not differ in being recognized
 (eliciting sexual reactions). However, on green ferns, heteromorphs were
 detected less often (elicited only fly-bys) than andromorphs but once
 detected, the morphs did not differ in being recognized. In contrast, when
 perched on a dowel with two male signal distractors, andromorphs were
 detected less often and once detected, were recognized less often than
 heteromorphs. Second, in fields where females foraged, andromorphs perched
 higher on vegetation than heteromorphs, and were more often in the
 vicinity of males. Neither harassment rates nor evasive behaviors differed
 between morphs. Males aggregated in high density near shore where solitary
 females were rare. Equilibrium frequencies of these and other color morphs
 should reflect the relative ease with which receivers detect and recognize
 them in the context where they are encountered.
description: HighContrastExperimentData are coded reactions of free-flying males to live, single individual glued to a dowel on the bank of lake. Treatments were glued male, glued blue female andromorph, glued green female heteromorph. See text for details on reactions, etc.HighContrast.xlsFern crypsis experimentData are results of free-flying males to single individual glued to the blade of a bracken fern at either high, medium, or low position. Reactions by males are scored identical to those in all 3 experiments.Fern_Hageni.xlsMale distractor ExperimentData are results of male distractor experiment. Controls were 3 individuals of the same color type (males, blue female andromorphs, or green female heteromorphs) glued to a dowel. Experimentals were two males plus a female (i.e. either green or blue) glued to a dowel in one of 3 positions. Analysis was identical to Fern Crypsis and High Contrast experiments.Stick_Hageni.xlsFIELD STUDY OF FOCAL INDIVIDUALSIndividual damselflies (i.e. males, blue female andromorphs, green female heteromorsphs) were caught, marked and the observed for as long as possible. Harassments by males were noted as was the behavior used by females to elude males. Perch heights were noted for a subset of individuals. Prey capture and predation on individuals were also noted. See text for details.FIELD_FOCAL.xlsMale survey on shore50-meter transects were surveyed on shore. After spotting a solitary male, all males within the meter of transect were noted. The data set includes only transects with 1 or more solitary males.Clump.xls