Sex-Specific Audience Effect in the Context of Mate Choice in Zebra Finches

Abstract

Animals observing conspecifics during mate choice can gain additional information about potential mates. However, the presence of an observer, if detected by the observed individuals, can influence the nature of the behavior of the observed individuals, called audience effect. In zebra finches (Taeniopygia guttata castanotis), domesticated males show an audience effect during mate choice. However, whether male and female descendants of the wild form show an audience effect during mate choice is unknown. Therefore, we conducted an experiment where male and female focal birds could choose between two distinctive phenotypes of the opposite sex, an artificially adorned stimulus bird with a red feather on the forehead and an unadorned stimulus bird, two times consecutively, once without an audience and once with an audience bird (same sex as test bird). Males showed an audience effect when an audience male was present and spent more time with adorned and less time with unadorned females compared to when there was no audience present. The change in time spent with the respective stimulus females was positively correlated with the time that the audience male spent in front of its cage close to the focal male. Females showed no change in mate choice when an audience female was present, but their motivation to associate with both stimulus males decreased. In a control for mate-choice consistency there was no audience in either test. Here, both focal females and focal males chose consistently without a change in choosing motivation. Our results showed that there is an audience effect on mate choice in zebra finches and that the response to a same-sex audience was sex-specific.

The role of the model in mate‐choice copying in female zebra finches

“…Thus, the choice positions covered only 16% of all possible perching positions. This method is an established measurement to determine sexual preferences in zebra finches (Kniel, Dürler, et al., ; Kniel, Schmitz, et al., ; Kniel et al., ; Witte, ; Witte & Caspers, ; Witte & Sawka, ). From this time, we also calculated the choosing motivation (total time spent in both mate‐choice zones during the 2 × 20 min mate‐choice test).…”

“…Test females that showed side biases during the first mate‐choice test, that is, those that spent more than 80% of their choosing time on the same side, even though we had switched the position of the stimulus cages, were excluded from the analysis in accordance with other studies (Dosen & Montgomerie, ; Hoysak & Godin, ; Kniel, Dürler, et al., ; Kniel, Schmitz, et al., ; Kniel et al., ; Schlupp & Ryan, ; Williams & Mendelson, ).…”

“…We measured the time [s] the test females spent perching on the outer one-third of the perches of choice adjacent to the stimulus males (mate-choice zone; grey area in tions. This method is an established measurement to determine sexual preferences in zebra finches (Kniel, Dürler, et al, 2015;Kniel, Schmitz, et al, 2015;Kniel et al, 2016;Witte, 2006b;Witte & Caspers, 2006;Witte & Sawka, 2003 the respective stimulus males spent in the front on their cage (outer one-third of the perches close to the test females) and we counted the number of courtship displays (whether or not males sang within a 10-s interval, either directed at females or undirected). Male song rate is known to influence female mate choice as females spend more time with males that sing more often compared to those that sing less often (Forstmeier & Birkhead, 2004 Test females that showed side biases during the first mate-choice test, that is, those that spent more than 80% of their choosing time on the same side, even though we had switched the position of the stimulus cages, were excluded from the analysis in accordance with other studies (Dosen & Montgomerie, 2004;Hoysak & Godin, 2007;Kniel, Dürler, et al, 2015;Kniel, Schmitz, et al, 2015;Kniel et al, 2016;Schlupp & Ryan, 1997;Williams & Mendelson, 2010).…”

“…This way, all stimulus and model birds were handled equally and not harmed in any way, but differed in their visible adornment. This method was successfully used before in a number of experiments with zebra finches (Kniel, Bender, & Witte, 2016;Kniel, Dürler, et al, 2015;Kniel, Schmitz, et al, 2015;Witte & Caspers, 2006;Witte & Sawka, 2003) and the Javanese mannikin Lonchura leuchogastroides (Plenge, Curio, & Witte, 2000;Witte & Curio, 1999;Witte, Hirschler, & Curio, 2000).…”

Test of the Deception Hypothesis in Atlantic Mollies Poecilia mexicana—Does the Audience Copy a Pretended Mate Choice of Others?

“…The audience effect is a wide-spread phenomenon and has been studied in various contexts (e.g., feeding [ 77 ], food caching [ 78 ], predator detection [ 79 ], and mate choice [ 80 ]). The audience effect has been studied in various taxa (insects [ 81 , 82 ], birds [ 83 , 84 , 85 , 86 , 87 , 88 ], mammals [ 78 , 79 , 89 , 90 , 91 , 92 ]), especially in fish: e.g., in the fighting fish Betta splendens [ 93 , 94 , 95 ], in the three-spine stickleback G. aculeatus [ 96 ], in the guppy P. reticulata [ 64 , 80 ], in the sailfin molly P. latipinna [ 97 , 98 ], and in the Atlantic molly P. mexicana [ 99 , 100 , 101 ].…”