Variation in the performance of cross-contextual displays suggests selection on dual-male phenotypes in a lekking bird

Abstract

Complex displays play an important role in female mate choice and male-male interactions for many species. Displays used in both inter-and intrasexual interactions offer an opportunity to examine how the ordering and structure of complex displays may vary with context. To understand how social context can influence the performance of complex displays, we investigated the predictability of display elements across displays in the presence and absence of females. The lance-tailed manakin, Chiroxiphia lanceolata, is a small lekking bird that performs complex, acrobatic displays. Pairs of alpha and beta males cooperatively display for females, but they also perform very similar displays in the absence of females. We quantified the performance of individual alpha and beta males within the dual-male display and the joint performance of the two males using Shannon's information entropy, and compared these values to understand how male display predictability varies with social context. Differences were assessed using generalized linear mixed models to account for repeated measures of male pairs. Predictability of individual performance within the dual-male interaction did not differ with female presence; however, entropy metrics describing the interaction of the alpha and beta male indicated that displays for females were more predictable and coordinated. This study provides a quantitative assessment of display element performance across different social contexts of female presence and absence, and suggests that the dual-male phenotype may be an important factor in female mate choice for cooperatively displaying species.

Why do females of a lekking species mate with multiple males?

“…comm.). (b) The performance of the complex, multimodal dual‐male dance display is more predictable and coordinated when a female is present (Vanderbilt, Kelley, & DuVal, 2015). (c) Females often visit several males and the same male multiple times before copulating (DuVal & Kapoor, 2015; DuVal et al, 2018).…”

Complexity of mutual communication in animals exemplified by paired dances in the red-crowned crane

“…Although previous studies have focused on individual levels (first, second, and part of the third levels: Pickering & Berrow 2001; first, second, and third levels: Vanderbilt et al 2015;fourth level: Sogabe & Yanagisawa 2008), no single study has considered all levels simultaneously. This is unfortunate, as consideration of all levels is necessary to answer biological questions on mutual communication (Takeda 2016).…”

“…These indices can consider information beyond simple measures such as the number of elements in a signal. However, only a handful of studies have used entropy to examine complex displays (Dalziell et al 2013;Vanderbilt et al 2015).…”

“…Using Shannon's entropy (see Appendix 2), Vanderbilt et al (2015) showed that the complexity of this mutual display was affected by the presence of a female. That is, dance performances by two males were better predicted (joint entropy was significantly lower) and coordinated (mutual information was significantly higher) in the presence of a female than in the absence of a female.…”

Synchronization of speed, sound and iridescent color in a hummingbird aerial courtship dive

“…In many cases, multimodal signals are also dynamic, and courtship displays in particular often have crucial motion-based elements 1,24 . The vigorous strut display of sage grouse ( Centrocercus urophasianus ) 25 and the coordinated dances of lance-tailed manakins ( Chiroxiphia lanceolata ) 26 are classic cases.…”