Conventional displays: Evidence for socially mediated costs of threat displays in a lizard

Abstract

Threat displays are used to settle the vast majority of contests between green anoles (Anolis carolinensis). While these displays have been the subject of a number of studies, very little is understood about the information they convey. Theoretical models divide displays into several types of signals, based on the mechanism that stabilizes their use: 1) performance signals, 2) handicapping signals, or 3) conventional displays. The existence of performance displays has excellent empirical support, as do models of their use. Handicapped signalling models, especially those relating to mate-choice, have been highly influential, though little evidence suggests that threat displays are, in fact, handicapping. Most threat displays appear to be conventional, but little empirical work documents conventional signalling systems. This study investigated the use of headbob, pushup, and lateral compression displays, and concluded that headbob cadence, a discrete signal with three alternative rhythms, is a conventional display indicating impending escalation. Pushups and lateral compression displays appear not to be handicaps, since neither indicates impending escalation, and they do not correlate with fighting ability or condition.

Female choice for male motor skills

“…The other major finding of the present study was that courtship activity in manakins is accompanied by transient, exceptional increases in metabolic rate reflected in extraordinarily high heart rates, such as are recorded in tiny hummingbirds during hovering flight [37]. There is no consensus that energy expenditure is a cost evaluated by females, because high metabolic rate is found to be related to reproductive success in some species [38,39] but not in others [40]. However, conventional techniques to measure metabolic rate, such as body weight changes and doubly labelled water, lack fine temporal resolution [41,42].…”

“…There is no consensus that energy expenditure is a cost evaluated by females, because high metabolic rate is found to be related to reproductive success in some species [38,39] but not in others [40]. However, conventional techniques to measure metabolic rate, such as body weight changes and doubly labelled water, lack fine temporal resolution [41,42].…”

Insights from Koala–Cattle Interaction Experiments: Koalas and Cattle May See Each Other as a Disturbance

“…Threat displays of animals involve ritualised aggression observed in conflict situations when confronting a threat, which can be either a conspecific competitor or a predator. Other than physical attacks, a threat display is a vital indicator of animals’ aggression and often leads to an escalation from non-contact to contact agonistic behaviour [ 57 , 58 , 59 ]. In this study, when confronted with the dog and koala models, cattle were more aggressive by being more inclined to display behaviours such as ground pawing, head swinging and charging.…”

Is honesty the best policy? Testing signal reliability in fiddler crabs when receiver‐dependent costs are high

“…Some models of aggressive contests predict that when potential combatants are in close proximity and are matched in size and intent, prefight displays will not be adequate to resolve contests (Maynard Smith 1982;Hurd 2004;Szamado 2008). In these cases, it is more likely that (i) contests would escalate to physical contact (high proximity costs), (ii) deceptive displays would be exposed and (iii) weaker individuals would be forced to pay the increased combat costs (Dawkins & Guilford 1991;Lailvaux, Reaney & Backwell 2009;Wilson et al 2009).…”