Background: Birds produce alarm calls to convey information about threats. Some Passerine alarm calls consist of several note strings, but few studies have examined their function. Previous studies have shown that Japanese Tits (Parus minor) can alter the calling rate and number and combination of notes in response to predators. We previously found the combinations of note types in Japanese Tit alarm calls to be significantly different in response to the Sparrowhawk (Accipiter nisus) and Common Cuckoo (Cuculus canorus). Methods:Through playback experiments, we tested whether the note strings in Japanese Tit alarm calls to the Common Cuckoo have different functions in conveying information. The note strings of selected alarm calls were divided into the categories of C and D, and different calls were then constructed separately based on the two note string categories. Original alarm calls (C-D), C calls and D calls were played back to male Japanese Tits during the incubation period.Results: Male Japanese Tits had a significantly stronger response to C calls than to C-D calls, and they showed a significantly stronger response to both C and C-D calls than to D calls, suggesting that Japanese Tits discriminated between the C and D calls. Conclusions:Our study demonstrated that the C-and D-category note strings of Japanese Tit alarm calls to the Common Cuckoo have different functions, which supports the previous finding that different note strings in an alarm call can provide different information to receivers. However, the exact meanings of these note strings are not yet known, and further investigation is therefore required.

No abstract

Despite the growing interest in consistent individual differences in behaviour (animal personality), the influence of social context on different behavioural types remains poorly understood. The suite of correlated behaviours within and across contexts is called behavioural syndromes. Most personality studies have investigated consistent individual behavioural types and their consequences in a asocial context, however few studies have considered the influence of social context on individual behaviour. In addition, the evolutionary and ecological consequences of personality differences in social context remain unknown. In the present study, we confirm individual personality in Great tits (Parus major) using room exploration and neophobia tests. As a result of these two tests, repeatability and correlational structure of two personality traits were investigated. Additionally we assessed the extent to which personality influences dominance in a social feeding context.Great tits remained consistent in their personality traits (exploration and neophobia). Individuals who explored a novel environment faster also approached a novel object faster, while those who spent more time exploring a novel environment were also slower to approach a novel object. In a social feeding context personality was linked to dominance: with proactive individuals being more likely to be dominant. Our result provides evidence of the importance of social context in a wild population of birds and may have fitness consequence, both for focal individuals and their conspecifics.

Consistent individual behavioral differences from other members of local populations are called animal personality, and a suite of these correlated behaviors generates a behavioral syndrome. Differential selection patterns among personality types can be largely influenced by predatory behavior. Prey has a large arsenal of antipredator behaviors at their disposal; However, how closely these behaviors are linked to personality is almost unknown. Using a social model species, the Great Tit, Parus major, we investigated whether antipredator behavior in response to predators is correlated with personality. First, we determined if individual differences in exploratory behavior were consistent across trials, that is, whether they were repeatable. Second, we looked into how antipredator behavior was correlated to personality. Individuals were subjected to two repeated trials of standard personality assays followed by an alternative control (Rock Pigeon, Columba livia domestica) and predator display (Eurasian Sparrowhawk, Accipiter nisus) treatment. We found that exploratory behavior was repeatable across trials and had a greater tendency for positive correlation with antipredator behavior when a predator model was displayed. Individuals that swiftly explored novel environments were slower to react to predators than those who explored the novel room slowly. As a result, our findings provide some of the first experimental evidence for a link between exploratory and antipredator behavior, suggesting that personality traits may impact individual fitness.