Raven food calls indicate sender’s age and sex

Abstract

BackgroundAcoustic parameters of animal signals have been shown to correlate with various phenotypic characteristics of the sender. These acoustic characteristics can be learned and categorized and thus are a basis for perceivers’ recognition abilities. One of the most demanding capacities is individual recognition, achievable only after repeated interactions with the same individual. Still, class-level recognition might be potentially important to perceivers who have not previously encountered callers but can classify unknown individuals according to the already learned categories. Especially for species with high fission-fusion dynamics that repeatedly encounter unknown individuals it may be advantageous to develop class-level recognition. We tested whether frequency-, temporal-, and amplitude-related acoustic parameters of vocalizations emitted by ravens, a species showing high fission-fusion dynamics in non-breeder aggregations, are connected to phenotypic characteristics and thus have the potential for class-level recognition.ResultsThe analysis of 418 food calls revealed that some components summarizing acoustic parameters were differentiated by age-classes and sex.ConclusionsTogether, the results provide evidence for the co-variation of vocal characteristics and respective sex and age categories, a prerequisite for class-level recognition in perceivers. Perceivers that are ignorant of the caller’s identity can thus potentially recognize these class-level differences for decision-making processes in feeding contexts.

Waste Disposal Sites as All-You-Can Eat Buffets for Carrion Crows (Corvus corone)

“…The size of non-breeder flocks, formed in several corvid species by juveniles and adults alike [30,31,32,33], might increase with food availability in early life stage periods. Additionally, non-breeders often inform each other about the location of food sources using food calls [1,14,34,35,36], and thus a large number of individuals can be recruited to food sources [14,34,37,38,39]. The similar attraction of large numbers of non-breeding individuals gathering at roosts and around substantial but ephemeral food sources is reported for carrion crows [13,15].…”

Raven Calls Indicate Sender’s Neural State

“…It was being used in mind, sequenced tool used test, awareness, learning and memory researches. More interestingly, Markus et al distinguished the gender and age of raven [47], and reported that ravens can predict future via their memory [24]. There are four behaviour categories of raven's call, including alarm, begging, flighting and singing.…”

Recognising the key role of individual recognition in social networks

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