Multiple sexual advertisements honestly reflect health status in peacocks (Pavo cristatus)

Abstract

The evolution of multiple sexual traits remains controversial and poorly understood in evolutionary biology. In many bird species, males exhibit complex courtships involving feather ornaments and behavioral display. Multiple traits may convey information on the genetic and phenotypic quality of males. In particular, fixed characters, such as feather ornaments (produced once a year during the annual molt in many bird species) might convey information about past male condition (at the time of trait development); whereas flexible traits such as behavioral displays should be sensitive to present condition. Here we show that both flexible behavioral displays and fixed feather ornaments of peacocks, used by females to choose a mate, honestly reflect health status. Correlative data showed that peacocks with high display rate (the number of behavioral displays per hour) and a large number of tail eyespots had low levels of circulating heterophils, suggesting better health status. Experimental activation of the immune system, through LPS injection, significantly reduced display rate compared to a control group. However, the sensitivity of a male display rate to the immune challenge was dependent on the number of tail eyespots: males with higher number of tail eyespots were better able to cope with the experimental immune challenge, and maintained their display rate at levels closer to the levels performed before the immune activation. These results are consistent with the idea that multiple signaling might enhance information reliability

Spots and stripes: ecology and colour pattern evolution in butterflyfishes

“…Nonetheless, there is currently limited evidence that spots/eyespots in butterflyfishes might function for sexual selection as sexual dimorphism is limited with both sexes exhibiting similar coloration [53], and we found no relationship between spots/eyespots and species' social system. However, spots and eyespots play a part in rspb.royalsocietypublishing.org Proc R Soc B 280: 20122730 sexual selection in other taxa; for example, female choice in some butterflies is based on the size and brightness of the eyespot 'pupils' [54], while in peacocks, the number of spots on the train is related to the male's health status and his ability to cope with an immune challenge [37]. In some species, the spatial arrangement of visual signals can facilitate multiple functions; for example, the dorsal wing patterns of butterflies promote sexual signalling while ventral characters serve for predator avoidance [55].…”

“…Obligate corallivory was of particular interest because it is uncommon in reef fishes other than chaetodontids [36] and could be associated with particular patterning. As planktivorous butterflyfishes are often found in shoals above the reef [37], we determined whether their colour patterns were more likely to be plain to provide concealment when viewed against an open water background.…”

Perception of health from facial cues

“…B 371: 20150380 the relative validity of cues [14,43], these are two areas of health perception which are still largely unexplored. The expectation may be that multiple cues of health are congruent (as has been argued for cues to mate quality [53][54][55][56]). …”

Enigmatic ornamentation eases male reliance on courtship performance for mating success

“…Elaborate sexual ornaments often accompany complex movements during animal displays (Zuk et al, 1995;Backwell et al, 1999;Hebets and Uetz, 2000;Madsen et al, 2004;Loyau et al, 2005;Murai and Backwell, 2006), making it feasible for selection to act on interactions between display properties and ornament characteristics (Kodric-Brown and Nicoletto, 2001;Candolin, 2003;Hebets and Papaj, 2005;Smith et al, 2009). An example of such naturally selected interactions is in the garter snake, Thamnophis ordinoides, where it is the combination of antipredator behavior and color patterns that is under selection (Brodie 1992).…”