Duet Function in the Yellow‐Naped Amazon, Amazona auropalliata: Evidence From Playbacks of Duets and Solos

Abstract

The question of why animals participate in duets is an intriguing one, as many such displays appear to be more costly to produce than individual signals. Mated pairs of yellow-naped amazons, Amazona auropalliata, give duets on their nesting territories. We investigated the function of those duets with a playback experiment. We tested two hypotheses for the function of those duets: the joint territory defense hypothesis and the mate-guarding hypothesis, by presenting territorial pairs with three types of playback treatments: duets, male solos, and female solos. The joint territory defense hypothesis suggests that individuals engage in duets because they appear more threatening than solos and are thus more effective for the establishment, maintenance and/or defense of territories. It predicts that pairs will be coordinated in their response (pair members approach speakers and vocalize together) and will either respond more strongly (more calls and/or more movement) to duet treatments than to solo treatments, or respond equally to all treatments. Alternatively, the mate-guarding hypothesis suggests that individuals participate in duets because they allow them to acoustically guard their mate, and predicts uncoordinated responses by pairs, with weak responses to duet treatments and stronger responses by individuals to solos produced by the same sex. Yellow-naped amazon pairs responded to all treatments in an equivalently aggressive and coordinated manner by rapidly approaching speakers and vocalizing more. These responses generally support the joint territory defense hypothesis and further suggest that all intruders are viewed as a threat by resident pairs.

Angry Birds Need Not Apply: A Perspective on the Flexible form and Multifunctionality of Avian Vocal Duets

“…The traditional manner in which the conflict vs. cooperation dichotomy has been addressed should also be re‐examined in the light of our results. The traditional experimental design contrasts the sex‐specific responses of a mated pair to duet and single‐sex playbacks, with the prediction that pairs will either respond more strongly to duets or equally strongly to all playbacks if they serve a cooperative, resource defence function, while responses to same‐sex playback will be higher if duets serve a mate‐guarding function (Levin ; Hall & Magrath ; Hall & Peters ; Benedict ; Douglas & Mennill ; Dahlin & Wright ). In some cases, support for a mate‐guarding hypothesis has stemmed from strong intrasexual responses by females to solo vocalizations, while males respond equally to solos and duets (Rogers et al.…”

“…These vocalizations appear to be a more complex behaviour than signalling alone, as they involve spatial and temporal coordination, increased attentiveness and potentially additional practice (Hall ). The complex nature of duet signals raises intriguing questions about how duets differ in form and function from solo vocalizations (Hall , ; McGregor ; Dahlin & Wright ). For this reason, duets have become an area of intense interest in the last couple of decades, with more than 60 new avian publications since 1990 alone (of more than 90 in the field overall).…”

Partners coordinate territorial defense against simulated intruders in a duetting ovenbird

“…A high degree of convergence and coordination between the sexes in playback responses has been found for a few other species (Benedict, ; Dahlin & Wright, ; Hall & Peters, ; Quirós‐Guerrero et al, ). In yellow‐naped amazons ( Amazona auropalliata ), partners did not differ in the approach behavior or vocal output (Dahlin & Wright, ). Similarly, in purple‐crowned fairy‐wrens ( Malurus coronatus ), partners coordinate their approach to the speaker and their vocal output in response to playbacks of duets (Hall & Peters, ).…”

“…Rufous horneros normally respond to conspecific playbacks by approaching and perching high on the speaker substrate (tree or light pole) instead of approaching the speaker itself or branches close to it, which is a typical response for many birds (Dahlin & Wright, ; Funghi, Cardoso, & Mota, ; Hall, ; Rogers et al, ). Rufous horneros then usually sing once and do not sing again for an average of 5.63 ± 3.81 min (mean ± SD , n = 110) after the playback.…”

Vocal dialects in parrots: patterns and processes of cultural evolution

“…In contrast, the majority of the species of parrots examined in both our literature search and our survey of Amazona do not defend resource-based territories and are not considered territorial in the same sense that the typical songbird is, although mated pairs in many species of parrots will vigorously defend the area directly around their nest cavity (Toft and Wright 2015). For example, the Yellow-naped Amazon produces pair duets around its nest site that appear to function in nest defence (Dahlin and Wright 2012a; Dahlin and Wright 2012b); these duets exhibit vocal dialects that are congruent with those seen in contact calls (Wright and Dorin 2001). Finally, both reviews of songbird dialects found an association of vocal dialects with migratory status, such that sedentary species and those with longer breeding seasons were more likely to have dialects, although dialects were also widespread in migratory species (Handley and Nelson 2005; Podos and Warren 2007).…”