Towards a new taxonomy of primate vocal production learning

Abstract

The extent to which vocal learning can be found in nonhuman primates is key to reconstructing the evolution of speech. Regarding the adjustment of vocal output in relation to auditory experience (vocal production learning in the narrow sense), effects on the ontogenetic trajectory of vocal development as well as adjustment to group-specific call features have been found. Yet, a comparison of the vocalizations of different primate genera revealed striking similarities in the structure of calls and repertoires in different species of the same genus, indicating that the structure of nonhuman primate vocalizations is highly conserved. Thus, modifications in relation to experience only appear to be possible within relatively tight species-specific constraints. By contrast, comprehension learning may be extremely rapid and open-ended. In conjunction, these findings corroborate the idea of an ancestral independence of vocal production and auditory comprehension learning. To overcome the futile debate about whether or not vocal production learning can be found in nonhuman primates, we suggest putting the focus on the different mechanisms that may mediate the adjustment of vocal output in response to experience; these mechanisms may include auditory facilitation and learning from success. This article is part of the theme issue ‘What can animal communication teach us about human language?’

Evolutionary significance of the variation in acoustic communication of a cryptic nocturnal primate radiation (Microcebus spp.)

“…This finding highlights that agonistic vocalizations do contain taxonomic and phylogenetic signatures (Doyle, 1978). This is in line with numerous studies in fish, insects, anurans (e.g., Amézquita et al, 2011), birds (e.g., Illera et al, 2018), and mammals (e.g., Campbell et al, 2010; Fischer & Hammerschmidt, 2020). On the other hand, we found no correlation with geographic distance, which is in contrast to studies on two singing mice species (Campbell et al, 2010), greenish warblers (Irwin et al, 2008), and crested gibbons (Thinh et al, 2011).…”

“…In mammals, various studies address micro‐ and macrogeographic acoustic variation in communication calls across populations, or closely related species (e.g., Macroscelidea: Faurie, 1996; Cetacea: Baron, Martinez, Garrison, & Keith, 2008, Samarra, Deecke, Simonis, & Miller, 2015; Artiodactyla: Gebler & Frey, 2005, Volodin, Nahlik, Tari, Frey, & Volodina, 2019; Carnivora: Perry & Terhune, 1999, Page, Goldsworthy, Hindell, & Mckenzie, 2002, Mizuguchi, Mitani, & Kohshima, 2016; Rodentia: Ancillotto et al, 2017, Chen, Su, Qin, & Liu, 2017; Chiroptera: Schöner, Schöner, & Kerth, 2010, Schuchmann & Siemers, 2010; Scandentia: Esser, Schehka, & Zimmermann, 2008; and Primates: Méndez‐Cárdenas, Randrianambinina, Rabesandratana, Rasoloharijaona, & Zimmermann, 2008, Fischer & Hammerschmidt, 2020). Acoustic variation across primate species has been related to selective forces (e.g., Braune, Schmidt, & Zimmermann, 2008; Masters, 1991; Schneider, Hodges, Fischer, & Hammerschmidt, 2008) or stochastic processes (e.g., Adret et al, 2018; Méndez‐Cárdenas et al, 2008; Meyer et al, 2012; Thinh et al, 2011).…”

Vocal convergence in a multi-level primate society: insights into the evolution of vocal learning

“…It has been argued that the human ability to imitate the utterances of others gradually evolved from the vocal plasticity observed in nonhuman primates [17,41]. We contend that vocal learning may be based on a variety of different mechanisms, including vocal convergence, ‘learning from success’, a form of usage learning that comprises the use of specific call variants because they are more likely to yield the desired response, as well as the spontaneous imitation of a recently formed auditory template [42]. Instead of conceiving vocal learning capacities as a continuum [43], we agree with other authors that vocal learning may be supported by a variety of different mechanisms [44].…”

Crossing the Rubicon: Behaviorism, Language, and Evolutionary Continuity

“…Kanzi is now said to understand some 3,000 spoken words (Raffaele, 2006), but has virtually no ability to speak. Fischer and Hammerschmidt (2019) note that the structure of chimpanzee calls is largely innate, with only limited evidence for modification or conventionalization, while in contrast "comprehension learning may be extremely rapid and open-ended" (p. 1).…”