DOI: 10.5061/dryad.pn974
title: Data from: No fitness benefits of early molt in a fairy-wren: relaxed sexual selection under genetic monogamy?

description: The evolution of male ornamentation has long been the focus of sexual
 selection studies. However, evidence is accumulating that sexually
 selected traits can also be lost, although the process is ill-understood.
 In male fairy-wrens (Malurus spp.), early molt into the seasonal breeding
 plumage is critical for obtaining extra-pair paternity (EPP), which
 reaches very high levels in these socially monogamous songbirds. A notable
 exception is the purple-crowned fairy-wren, Malurus coronatus, which, like
 its congeners, breeds cooperatively, but where EPP is very rare.
 Nevertheless, males develop a conspicuous seasonal breeding plumage at
 highly variable times. Based on 6 years of molt data collected for 137
 individuals, we investigated the adaptive significance of pre-breeding
 molt timing as a sexual signal under (near) genetic monogamy. Molt timing
 varied between and within individuals with age and climate: molt was
 completed earlier in older males and after wetter years. Despite its
 potential to act as a sexual signal of male quality, fitness benefits and
 costs of early molt appear limited: molt timing did not correlate with 1)
 the likelihood of gaining a breeding position; 2) female mate preference
 (EPP/cuckoldry, divorce); 3) female reproductive investment (breeding
 timing, clutch size, number of clutches); 4) breeding performance
 (hatching success, fledging success, fledgling survival, annual
 reproductive success); and 5) male survival. However, although molt timing
 did not predict which subordinates would become breeders, breeders molted
 earlier than subordinates. The lack of EPP in this species might imply
 relaxed sexual selection on early molt with potential to lead to trait
 disappearance.
description: Pre-breeding moult data
 from male purple-crowned fairy-wrensThe data file includes
 pre-breeding moult profiles of male purple-crowned fairy-wrens based on
 plumage colouration scores collected in the field over a six-year period,
 as well as life-history-related information for each
 individual.Male_Moult_Database.csvPre-breeding moult and breeding data from male purple-crowned fairy-wrensThe data file includes information on pre-breeding moult and breeding activity of male purple-crowned fairy-wrens collected in the field over a six-year period.Breeding_Database.csvPre-breeding moult and social improvement data from male purple-crowned fairy-wrensThe data file includes information on within-individual social improvement, aging and associated variation in pre-breeding moult timing in male purple-crowned fairy-wrens, based on data collected in the field over a six-year period.Social improvement_Moult.csvPre-breeding moult and gain of dominance data from male purple-crowned fairy-wrensThe data file includes data on individual pre-breeding moult timing and the outcome of competitions for a dominance position in male purple-crowned fairy-wrens, collected in the field over a six-year period.Dom Acq_Comparison_Moult.csvPre-breeding moult and divorce data from male purple-crowned fairy-wrensThe data file includes data on pre-breeding moult timing and the outcome of divorces in male purple-crowned fairy-wrens, collected in the field over a six-year period.Divorce_Comparison_Moult.csvPre-breeding moult and rainfall data in male purple-crowned fairy-wrensThe data file includes information on pre-breeding moult completion and rainfall in associated years for male purple-crowned fairy-wrens, collected in the field over an 11-year period.Rainfall_Moult.csv