Personality-dependent response to field playback in great tits: slow explorers can be strong responders

•The response to playback in great tits is dependent on their exploration score.•Surprisingly, birds with low exploration scores responded most aggressively.•These results are in contrast with previous findings.•We hypothesize that this pattern is due to differences in relative signal strength.•Exploration score is important for interpreting playback experiments.

Animal personalities can play an important role in how individuals deal with specific social situations, which may have important fitness consequences. A link between personality and social skills seems obvious from a human perspective and it is therefore surprising that relatively few studies have looked at the effect of animal personality on communicative interactions. In this study we tested the evidence for personality-related variation in birds during vocal interactions in the field. We scored individual variation in exploratory behaviour of great tits, Parus major, in repeated trials of a novel environment test in the laboratory and related this score to approach and vocal behaviour in response to playback of conspecific songs in the field. Contrary to our expectation, we found males with low exploration scores approached the speaker more closely than birds with high exploration scores. Birds with high exploration scores seemed to respond less aggressively while dealing with the simulated intruder vocally by switching song types more often. Our results suggest that slow-exploring birds in the laboratory respond more strongly during natural interactions in the field. An independent and very similar study also revealed a correlation between personality score and playback response, but with a seemingly contrasting outcome. A comparison of the two studies provides insights into the complexity of interpreting playback results and territorial response patterns in general.