Behavioural Processes 85 (2010) 36–41 Contents lists available at ScienceDirect Behavioural Processes journal homepage: www.elsevier.com/locate/behavproc Using video playback to study the effect of an audience on male mating behavior in the Sailfin molly (Poecilia latipinna) A.M. Makowicz a,∗ , M. Plath b , I. Schlupp a a Department of Zoology, University of Oklahoma, 730 Van Vleet Oval, Norman, OK 73019, USA b Department of Ecology and Evolution, J.W. Goethe University Frankfurt, Siesmayerstrasse 70-72, D-60054 Frankfurt am Main, Germany article info Article history: Received 10 September 2009 Received in revised form 13 May 2010 Accepted 3 June 2010 Keywords: Audience effect Coercive mating Communication networks Foraging Sexual conflict Sperm competition abstract Sexual conflict in poeciliid fishes is well-documented, particularly male sexual harassment and its effects on females. For instance, male attempts to force copulations influence female feeding, energy allocation, and preference for shoaling partners. However, there has been little research conducted to determine how the social environment shapes the occurrence and intensity of sexual harassment. In this study we ask whether an audience male influences the sexual behaviors of a focal male, the correlated feeding time reduction of female Poecilia latipinna, and if the size of the audience male (larger or smaller than the focal male) influences these behaviors. We presented a video of a male, either smaller or larger than the focal male, or an empty tank (control) to a female interacting with a male or female partner and measured feeding times and sexual behaviors. We found that male sexual behaviors increased in the presence of an audience male, especially if the audience male was larger than the focal male. Females fed more in the presence of a partner female than in the presence of a male, which was independent of the audience (i.e., video treatment). Focal female aggression towards the partner female increased with the size of the audience male. The present study shows that an audience male has multiple interacting influences on both male and female behavior. © 2010 Elsevier B.V. All rights reserved. 1. Introduction Sexual conflict affects various aspects of female life histories (Arnqvist and Rowe, 2005). For example, male sexual harassment can lead females to alter their time budgets because they need to monitor and flee surrounding males (e.g., Dadda and Bisazza, 2006; Plath et al., 2007) and thus pay opportunity costs in terms of reduced food uptake (e.g., insects: Rowe et al., 1994; Stone, 1995; catshark, Scyliorhinus canicula: Kimber et al., 2009; livebear- ing fishes, Poecilia spp.: Magurran and Seghers, 1994; Schlupp et al., 2001; Plath et al., 2003; Gambusia spp.: Dadda et al., 2008; Plath et al., 2007; Arrington et al., 2009). Male sexual harassment can also increase female predation risk and energy expenditure, reduce female lifespan, or cause physical or genital damage, and increase parasite or toxin transmission (Chilvers et al., 2005; Eady et al., 2007; Gay et al., 2009; Kimber et al., 2009; Magurran and Nowak, 1991; Rowe et al., 1994). The present study investigates the intensity of male pursuit of females, and female responses to this sexual harassment, in the context of the multiple ways in which ∗ Corresponding author at: Department of Zoology, University of Oklahoma, 730 Van Vleet Oval, Rm 314, Norman, OK 73019, USA. Tel.: +1 405 974 1970; fax: +1 405 325 6202. E-mail address: Amber.M.Makowicz-1@ou.edu (A.M. Makowicz). male–female interactions are embedded in social (or communica- tion) networks. Communication between two individuals usually occurs in the presence of an audience, i.e. non-interacting individual(s). This audience can be conspecific, heterospecific, and the same or oppo- site sex (Leaver et al., 2007) and may influence the behaviors of the interacting pair (Matos and McGregor, 2002; Matos and Schlupp, 2005). With respect to male mate preferences, male Atlantic mol- lies (Poecilia mexicana) reduce and even switch their preference to deceive their audience when it is another male (Plath et al., 2008b). In fighting fish (Betta splendens), the sex of the audience influences male–male aggressive displays. Focal males tended to bite more, with a lower latency period, when in the presence of a male versus that of a female (Matos and McGregor, 2002). This social environment can play an important role in sexual conflict, often resulting in an increase or decrease of sexual or aggressive behaviors (Dzieweczynski et al., 2005; Matos and McGregor, 2002; Plath et al., 2008b; Padur et al., 2009). In many livebearing fishes (Poeciliidae), males attempt to mate as often as once a minute (Magurran and Seghers, 1994; Plath et al., 2005), while females are mostly non-responsive to male approaches (Liley, 1983; Houde, 1997; Brewster and Houde, 2003; Deaton, 2008). Most of these mating attempts are coercive, with males continually harassing and trying to forcefully copulate with females (Schlupp et al., 2001; Agrillo et al., 2006; Plath et al., 2003, 0376-6357/$ – see front matter © 2010 Elsevier B.V. All rights reserved. doi:10.1016/j.beproc.2010.06.003