Heterosexual Signalling By the Lizard Anolis Carolinensis, with Intersexual Comparisons Across Contexts

Abstract

SummaryWe quanti ed the structure and use of signals exchanged by males and females within the female-defence polygyny of the lizard, Anolis carolinensis. During heterosexual interactions, both sexes performed three kinds of stereotypic headbob displays (A, B, and C) with equal precision. These three display types were essentially identical to A, B, and C display types previously documented for both sexes during consexual contests, and for males when displaying alone (non-directed context). Therefore, there is no courtship-speci c headbob display in A. carolinensis. Although interacting males and females displayed at a similar mean frequency (»20 displays/h), signalling was sexually dimorphic in that: (1) males used predominately C displays (89%), whereas females used predominantly A and B displays (48% and 50%, respectively); (2) males extended their dewlaps with almost every display (98%), whereas females extended their dewlaps with few displays (<2%); (3) males sequenced 80% of displays in volleys of two or more displays, whereas females performed only 12% of displays in volleys; and (4) males concluded 22% of displays with shudderbobs (i.e. display modi er composed of shallow, quick, double bobs), whereas females never appended displays with shudderbobs. From eld and laboratory data on A. carolinensis signal behaviour during other social contexts and the species' female-defence mating system, we interpret heterosexual signalling from a perspective of intrasexual selection to discuss the: (1) absence

Do displays and badges function in establishing the social structure of male toad-headed lizards, Phrynocephalus vlangalii?

“…Such signals allow a rival male or female to identify the quality of a dominant individual without having to engage in physical combat (Osborne 2005). Specific display behaviors may transmit information about an individual's aggressiveness to conspecifics and thereby influence the outcome of dominance interactions (Hover and Jenssen 1976;Orrell and Jenssen 2003;Osborne 2005). Our results showed that resident males of P. vlangalii engaged in tail curling and agonistic interactions more frequently than floater males.…”

“…Displays are important visual signals (Kim 1995;Zug et al 2001;Brandt 2003), and are known to predict a lizard's aggression, endurance and performance capacity (Hover and Jenssen 1976;Brandt 2003;Orrell and Jenssen 2003;Perry et al 2004;Osborne 2005). Such signals allow a rival male or female to identify the quality of a dominant individual without having to engage in physical combat (Osborne 2005).…”

“…In contrast, displays are behaviors that consist of variable body movements, such as the raising and lowering of the head and dewlap in the green anole Anolis carolinensis (Carpenter 1967;Jenssen 1977). Display behaviors are also known to predict an individual lizard's aggressiveness and performance capacity (Hover and Jenssen 1976;Brandt 2003;Orrell and Jenssen 2003;Perry et al 2004;Osborne 2005). Individuals exhibiting different social statuses are expected to develop differences in their display behaviors and badges (Zucker 1989;Andersson et al 2002;Lopez et al 2004;McElroy et al 2007).…”

An Ethogram of the Toad-headed Lizard Phrynocephalus vlangalii during the Breeding Season

“…We were then able to choose the proper recording method based on the characters of different behavioral elements. For example, time sampling is suggested to be suitable for the recording of acts, whereas instantaneous sampling may be more suitable for the recording of postures (Orrell and Jenssen, 2003;Bloch and Irschick, 2006;Martin and Bateson, 2007).…”

Memory of opponents is more potent than visual sign stimuli after social hierarchy has been established

“…Stereotypical behaviors, dewlap and/ or nuchal crest extension, lateral compression, body color and eyespots are the most obvious signals, and are used for different functions, and produce different neurochemical output in male and female Anolis carolinensis [1,19,69,79]. Highly ritualized behavioral displays are characterized by three display action patterns of head nods and dewlap extension, with tempo but not cadence distinguishing function [58]; the imparted messages depending on context plus the rank and sex of the lizard [1,19,70,79]. It may be that different components from a multilayered signal redundancy, which includes the eyespots, are important for opponent recognition in A. carolinensis, as has been demonstrated for mate recognition in frogs [63].…”