Grasshopper calling songs convey information about condition and health of males

Abstract

Females of the grasshopper Chorthippus biguttulus invest much more in the offspring than do males. As a consequence, females are the more selective sex and exert a sexual selection on males by responding to the songs of certain conspecific males while rejecting others. What kind of information about the sender may a female obtain from a male's song, in addition to its species identity? We searched for correlations between a series of song features and morphometric parameters of individual males. In addition, also the immunocompetence of males was assessed by implanting small pieces of nylon thread. We found significant, positive correlations between certain song characteristics and indicators of male size and immunocompetence. Thus, grasshopper females may--in principle--be able to judge a male's condition and health from the acoustic signals he produces.

How grasshoppers respond to road noise: developmental plasticity and population differentiation in acoustic signalling

“…b). The latter is established as a sexually selected song trait in this species (von Helversen & von Helversen ; Klappert & Reinhold ; Stange & Ronacher ,b) and tended to be higher in songs produced by roadside males in a previous study (Lampe et al . ).…”

“…We tested for the interaction effect to detect a potentially habitat-dependent predisposition of ontogenetic signal adjustment in relation to different levels of noise exposure. Body mass was included into these models as a fixed effect covariate because measures of body size have been reported to affect both song traits in earlier studies (Lampe et al 2012;Stange & Ronacher 2012b). We included individual, population and location (see Table 1) as random effects to account for the nested dependency structure of the data (individual was included here because we recorded three songs per male and used all in the analyses).…”

Insect Hearing

“…In the bow-winged grasshopper ( Chorthippus biguttulus ), there is a positive correlation between some song features and male size and condition (Stange and Ronacher 2012 ). Direct benefi ts of female choice on male song have been explored in the variable fi eld cricket Gryllus lineaticeps (reviewed in Wagner 2011 ).…”

Condition‐dependence and sexual ornamentation: Effects of immune challenges on a highly sexually dimorphic grasshopper

“…Little is known on what features of the song are important to females of G. sibiricus , but it is possible that properties of the song serve also to signal male quality (Berger & Gottsberger, ). In other orthopteran species songs convey information about different aspects of male quality, such as immunocompetence and overall health (Stange & Ronacher, ), and are correlated to other proxies of condition such as fluctuating asymmetry (Simmons & Ritchie, ) and energy invested in sound production (Klappert & Reinhold, ; Rebar et al ., ; Simmons et al ., ).…”