Impact of group size and social composition on group vocal activity and acoustic network in a social songbird

Abstract

International audienceIn social species individuals living in the same group may synchronize activities such as movements, foraging or antipredator vigilance. Synchronization of activities can also be observed between partners especially during breeding and can be crucial for breeding success. Vocalizations are behaviours that can be coordinated between individuals, but simultaneous vocalizations in groups have mostly been considered as noise that does not bear any information. Indeed, little is known about the structure and function of vocal communications involving a network of individuals. How individual vocal activity forms part of the communal sound and how the group influences individual vocal activity are questions that remain to be studied. Zebra finches, Taeniopygia guttata, are social, monogamous songbirds that form lifelong pair bonds. In the wild, they are typically found in small groups, with the pair as the primary social unit, and they gather in ‘social’ trees where both females and males produce vocalizations. Here we investigated in the laboratory the influence of group size and composition on general vocal activity and synchrony, as well as the influence of pair bond and spatial location on the finer characteristics of dyads' vocal interactions. We used a set-up that locked the birds at fixed spatial positions of our choosing to control the proximity network and allowed us to match most of the vocalizations with specific in- dividuals. We used an in-house software suite that automatically detects vocalizations from hours of passive recording. We found that zebra finch groups synchronized their general vocal activity with waves of collective vocalizations, which depended on both the size and the composition of the group. The acoustic network was shaped by pair bonds at different timescales. Birds preferentially vocalized close in time to (synchrony) or directly after (turn taking) their partner when it was present and the nearest neighbour when the partner was not available

Anthropogenic noise affects female, not male house wren response to change in signaling network

“…Social factors may also play a key role in patterns of vocal coordination. Captive non‐breeding zebra finches ( Taeniopygia guttata ) coordinated bouts of singing depending on group size and pairing status (Fernandez et al., 2017). In wild populations of birds, vocal coordination may only occur during early stages of breeding.…”

“…But additional energy expenditure to maintain coordinated song patterns with neighbors may not benefit males once paired. Moreover, the temporal window that we considered in this study (blocks of 10‐min periods of singing) may be too short to detect vocal coordination, as evidence of coordination patterns have been found among groups of birds recorded over several hours and days (Araya‐Salas et al., 2017; Fernandez et al., 2017; Taff, Patricelli, & Freeman‐Gallant, 2014).…”

“…In addition to limitations imposed by environmental constraints, variation in signaling patterns among callers may be context‐dependent (Snijders & Naguib, 2017). Between rival males, vocal coordination, or the probability of song alternation and overlap may depend on social conditions, such as group size and whether or not males have paired (Fernandez, Vignal, & Soula, 2017). In response to intruders on the territories of neighbors, males respond more strongly when intrusions are in close proximity to their own territory (Foote, Fitzsimmons, Mennill, & Ratcliffe, 2011) or reflect a greater risk (Fitzsimmons, Foote, Ratcliffe, & Mennill, 2008).…”

“…To test our hypothesis, we used playbacks to simulate territorial intrusions with and without anthropogenic noise on territories of established males (hereafter, “challenged males”), but focused on the vocal behavior of neighbors to explore whether environmental factors (noise and distance from challenged male) and social context (nesting stage) influenced singing. We measured vocal coordination, or patterns of signal overlap and alternation between challenged and neighboring males (Araya‐Salas, Wojczulanis‐Jakubas, Phillips, Mennill, & Wright, 2017; Fernandez et al., 2017; Masco, Allesina, Mennill, & Pruett‐Jones, 2016), and total song output by neighbors in response to simulated intruders to understand factors that influence the vocal responses of neighbors. As the responses of neighboring males and females to challenged males may differ (Snijders et al., 2017), we evaluated female vocal responses by determining whether neighboring females sang during treatments.…”

Vocal networks remain stable after a disturbance in Emei music frogs

“…Although several studies have focused on temporal changes in social networks (Bar Ziv et al, ; Blaszczyk, ; Maldonado‐Chaparro, Hubbard, & Blumstein, ; VanderWaal, Atwill, Isbell, & McCowan, ), most studies have utilized association networks based on physical contact, spatial proximity, or co‐occurrence. To date, only a small number of studies have focused on vocal networks in animal populations (Fernandez, Vignal, & Soula, ; Kulahci, Ghazanfar, & Rubenstein, ; Kulahci, Rubenstein, & Ghazanfar, ; Snijders & Naguib, ).…”