Temporal patterns in Cape fur seal (Arctocephalus pusillus pusillus) mother and pup attraction calls

Vocal recognition is widespread in the animal kingdom, and a necessary tool for offspring survival some groups. Temporal patterns of vocalisations can facilitate communication convey information such as identity, emotional state, or motivation caller. While pinniped (i.e., walrus, eared true seals) are generally well studied, captive pinnipeds show strong timing abilities, little known about temporal structure their calls wild. Here, we followed Cape fur seals (Arctocephalus pusillus pusillus) during spontaneous search efforts at Cross Seal Reserve Namibia. To investigate rhythmic patterning seal attraction calls, analysed call bouts 80 mothers 148 pups. We assessed relative vocal undertaken by pups calculating calling rates, inter-call intervals (periods silence between vocalisations), total time spent per bout. explore visualised plotting events frequency histograms inter-onset-intervals each two consecutive A normalized Pairwise Variability Index was calculated individual to underlying compared Pups produced more search, vocalised higher took shorter breaks than females. Even though female were much longer, there no significant difference females vocalising All animals seemingly random intervals, with distinguishable pattern, suggesting that these do not encode identity mother-pup reunions. However, numerical analysis showed potential asynchronous within age classes, possibly used anti-masking. Our results indicate invest energy differently while effort comparable, reunions seem be driven mostly young.