How great tits respond to urgency‐based information in allopatric Southern house wren mobbing calls

Abstract

Many species of birds use alarm calls to signal information about predators, including the level of threat. Previous playback experiments suggest that the urgency response towards heterospecific calls is phylogenetically conserved, notably in the Paridae family. Using playback experiments conducted on European great tits (Parus major), we tested whether this species perceives information about urgency in mobbing calls produced by an allopatric non‐Paridae species, the Southern house wren (Troglodytes aedon bonariae), by broadcasting calls with high‐calling rate (high threat) and calls with low‐calling rate (low threat). We found that great tits tend to approach the loudspeaker during playbacks of calls with high‐calling rate more often than during playbacks of calls with low‐calling rate. Female great tits gave more calls during playbacks of calls with high‐calling rate than during playbacks of calls with low‐calling rate, whereas there was no significant difference in the number of calls given by males between playbacks of calls with high‐ and low‐calling rates. Thus, our results suggested that great tits perceived the urgency message encoded in calls given by an allopatric non‐Paridae species.

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

“…We also observed a decline in vigilance as group size increased: a result that is in line with the majority of findings from other studies in birds and mammals (meta-analysis in birds: Beauchamp, 2008; meta-analysis in mammals: Beauchamp et al, 2021). Finally, we found that the ability to respond to risk-based information contained within conspecific alarm calls is not affected by sex, which is in accordance with previous findings in a mammal (Randall & Rogovin, 2002), but not in accordance with findings in a bird species (Dutour et al, 2022a).…”

“…Although we found that magpies can appropriately respond to urgency information contained in conspecific alarm calls, the mechanisms for understanding risk-based information are still unclear. Magpies may learn to associate a type of alarm call with a particular event through social interactions/learning or may innately respond more strongly to greater call repetition (Randler, 2012;Dutour et al, 2022a). Additional experiments, such as responses of nestlings to playbacks of low-and high-urgency calls would help determine the developmental mechanisms of alarm call responsiveness.…”

“…Randall and Rogovin (2002) found no sex effect in great gerbils (Rhombomys opimus). A recent study found that female great tits (Parus major) gave more alarm calls during playbacks of low-urgency calls than during playbacks of high-urgency calls, whereas there was no significant difference in the number of alarm calls given by males between playbacks of low-urgency and high-urgency calls (Dutour et al, 2022a). More studies are needed to determine sex differences in the ability to understand risk-based information contained within alarm calls and respond accordingly.…”

Acoustic cues and season affect mobbing responses in a bird community

“…Our experiment does not add any insights on which criteria was used by birds. Based on the current literature, the duty cycle is probably one major coding strategy for increased risk in Parids (Landsborough et al 2020, Salis et al 2022), and Parids modify their response to unknown non-Parids calls with different duty cycles (Dutour et al 2022). Yet, great tits can also recognize caller identity, as they increased their mobbing response toward soundtracks made with calls of several individuals compared to soundtracks with only one individual calling (Dutour et al 2021).…”

Information transfer during mobbing: call rate is more important than the number of callers in a southern temperate passerine

“…Callers can indicate the level or immediacy of a threat by modifying mobbing calls in relation to the degree of perceived risk (Evans et al 1993a In birds, more dangerous threats tend to elicit higher calling rates ( Wheatcroft 2015; Fernández and Carro 2022). Higher calling rates can also trigger a stronger mobbing response in allopatric birds, suggesting thatthey innately respond more strongly to greater call repetition (Randler 2012;Dutour et al 2022). Thus, the information encoded in calling rate may be particularly useful to receivers in deciding whether to respond to mobbing calls or not.…”