‘Virtual Parrots’ Confirm Mating Preferences of Female Budgerigars

Abstract

Parrots comprise one of the several taxa in which life‐long learning of new vocal signals used in intraspecific communication is known to occur routinely. The functions and evolutionary bases of this ability are largely unknown. In the budgerigar (Melopsittacus undulatus), males typically imitate their partner’s contact call type during pair formation. However, a female’s initial choice among unfamiliar males is not based on their production of her call type, because birds without prior social contact rarely produce the same call type. Here, we demonstrate that female budgerigars prefer unfamiliar males with calls that are similar to their own, as measured by spectrogram cross‐correlation, but which are not imitations. This was shown by training females via operant conditioning to control access to movies of courting males and by systematically varying the audio tracks of these movies. Females learned this task easily and interacted with virtual males as if they were real. This methodology will be useful for exploring functions and mechanisms of social communication, because it eliminates the confounding impact of short‐term changes in a stimulus individual’s behavior on a test individual’s response. Our results suggest that the neuroplastic vocal abilities of budgerigars, and perhaps other parrots, have been shaped by sexual selection.

A test of multiple hypotheses for the function of call sharing in female budgerigars, Melopsittacus undulatus

“…Although both sexes can imitate the calls of other individuals, females do so more slowly, and when in male–female pairs, the males imitate the females’ calls (Hile et al 2000; Hile and Striedter 2000). Support for a sexual selection and/or pair-bonding function has been supported in male–female studies (Hile et al 2000; Hile et al 2005; Moravec et al 2006; Moravec and Striedter 2010), but since call sharing also occurs between same-sex individuals, it is likely that imitation serves additional functions beyond promotion of the pair bond. Our work supports the hypothesis that call matching may serve different function(s) depending on the social relationships between the individuals.…”

“…Other hypotheses have been proposed for call sharing including the mate attraction and pair-bonding (Hile et al 2000; Moravec et al 2006; Keenan and Benkman 2008; Sewall 2009; Moravec and Striedter 2010) and group cohesion (Brown 1985; Bradbury et al 2001; Yurk et al 2002) hypotheses. The mate attraction and pair-bonding hypothesis is specific to mated pairs and suggests that the process of convergence or imitation can have two effects on pair bond formation: (1) it may help reinforce social bonds, and (2) it may enhance individual recognition of one's mate (Hile et al 2000; Moravec et al 2006; Keenan and Benkman 2008; Sewall 2009; Moravec and Striedter 2010).…”

“…The mate attraction and pair-bonding hypothesis is specific to mated pairs and suggests that the process of convergence or imitation can have two effects on pair bond formation: (1) it may help reinforce social bonds, and (2) it may enhance individual recognition of one's mate (Hile et al 2000; Moravec et al 2006; Keenan and Benkman 2008; Sewall 2009; Moravec and Striedter 2010). The mate attraction and pair-bonding hypothesis thus is not relevant for single-sex groups.…”

“…Call sharing in this species appears to exhibit different patterns depending on how groups are formed. In male–female pairs, males typically imitate female calls, and this process appears to contribute to pair bond formation and maintenance (Hile et al 2000; Hile et al 2005; Moravec et al 2006; Moravec and Striedter 2010). Imitation also occurs in all-male groups when immigrants are introduced to a new flock (Bartlett and Slater 1999; Young 2011).…”

Experimental evidence of contagious yawning in budgerigars (Melopsittacus undulatus)

“…Unlike chimpanzees or wolves, however, in which observing unfamiliar conspecifics may elicit hostility and familiarity biases for contagious yawning have been reported (Campbell and de Waal 2011;Romero et al 2014), budgerigars show more fluid flocking and thus we did not expect a strong bias for contagious yawning. Since previous research has demonstrated that budgerigars respond to video displays of real and virtual conspecifics (Mui et al 2008;Moravec et al 2010;Mottley and Heyes 2003), Study 2 compared the yawn frequency of the same birds from Study 1 during exposure to video presentations of yawns versus control behaviors.…”