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.