Australian Magpies discriminate between the territorial calls of intra‐ and extra‐group conspecifics

Abstract

The ability to discriminate between individuals or classes of individuals based on distinctive cues is considered a vital skill in cooperative and territorial species. Here, we used playback experiments to determine whether Western Australian Magpies Gymnorhina tibicen dorsalis discriminate between the territorial carolling calls of intragroup and extra-group conspecifics. Magpies responded more strongly to the playback of carolling calls from extra-group individuals than to the playback of carolling calls from intra-group individuals, spending more time vigilant and carolling in response to extra-group carols. Our results suggest Western Australian Magpies are able to distinguish between individuals within and outside of their social group using only vocal signals and expands on growing research reporting vocal discrimination and individual recognition abilities across species.

Cognition mediates response to anthropogenic noise in wild Western Australian magpies (Gmynorhina tibicen dorsalis)

“…The following behaviours were assessed via video analysis: whether focal individuals fled following playback, the time focal individuals spent vigilant in the 30 s post‐playback (birds were considered vigilant when they were displaying an erect posture and were scanning the surrounding environment; Blackburn, Ridley, & Dutour, 2022; Zhou et al, 2019) and the time taken for focal individuals to return to normal behaviour post‐playback, to a maximum of 60 s (birds were considered to have returned to normal behaviour when they spent a minimum of three consecutive seconds foraging and non‐vigilant). The video analyst (GB) was blind to playback treatment during video analysis.…”

Anthropogenic noise affects vocalisation properties of the territorial song of Western Australian magpies

“…Such reductions in vocalisation rates during anthropogenic noise have also been found in flying foxes ( Pteropus poliocephalus ) (Pearson & Clarke, 2018), reed buntings ( Emberiza schoeniclus ) (Gross et al, 2010), and several anuran species (Caorsi et al, 2017; Cunnington & Fahrig, 2010), and are hypothesized to occur as a means for individuals to avoid the energetic costs associated with vocalising when their vocalisations are likely to go unheard (Franz & Goller, 2003; Hart et al, 2015). While declines in carol rate during anthropogenic noise may be beneficial for magpies in the short-term, if increases in anthropogenic noise lead to more sustained reductions in vocalisation rates, this could affect social structure and territory defence in this species, as carols play an important role in these aspects of social life (Blackburn et al, 2022; Dutour & Ridley, 2020).…”

“…Magpies are highly territorial, and produce multiple complex vocalisations (Dutour & Ridley, 2020; Dutour et al, 2020; Walsh et al, 2023). The main territorial song of magpies – known as “carols” – are high-amplitude, slurred songs sung by individuals to advertise territory ownership and defend territories (Blackburn et al, 2022; Carrick, 1963; Dutour & Ridley, 2020). Previous work on this sub-species revealed that females carol more often than males (Dutour & Ridley, 2020), therefore in this study we focused on female carols.…”

Western Australian magpies respond to urgency information contained in conspecific alarm calls

“…0.13 s (a natural interval during alarm call responses to an observed terrestrial predator, in this case a red fox). Each focal magpie received both playback treatments of alarm calls from the same existing group member since magpies can discriminate between the calls of intra-and extra-group conspecifics (Blackburn et al, 2022). The contact calls with four notes were made by repeating a single note at a natural emitted interval (mean: approx.…”