Data to support playback experiments to female northern elephant seals ...

• Main Author: Casey, Caroline
• Format: Dataset
• Language: English
• Published: Dryad 2021
• Subjects: Elephant Seal; Elephant Seals
• Online Access: https://dx.doi.org/10.5061/dryad.hmgqnk9h7; https://datadryad.org/stash/dataset/doi:10.5061/dryad.hmgqnk9h7

Bonding between mothers and their young is fundamental to mammalian reproductive behaviour and individual fitness. In social systems where the risk of confusing filial and non-filial offspring is high, mothers should demonstrate early, strong, and consistent responses to their kin throughout the period of offspring dependence, irrespective of maternal traits such as experience and temperament. We tested this hypothesis through playback experiments in the northern elephant seal Mirounga angustirostris, a phocid species that breeds in high-density colonies. We found that mothers recognised their offspring throughout lactation and as early as 1-2 days after parturition. Age and aggressiveness level of mothers did not predict their response strength to filial playback treatments, nor did pup age or sex. Some mothers showed great consistency in behavioural responses throughout the lactation period, while others were less predictable. The strength of a female’s response did not influence her pup’s weaning weight, ... : Playback experiments: We tested 22 mothers during early, mid, and late lactation (weeks 1, 2, and 3) when filial pups were 7.5 ± 1.2 days, 14 ± 1.8 days, and 20.4 ± 3.2 days old. During the first season, playbacks were conducted with six untagged adult females. To avoid possible replication the following season, we selected 16 tagged individuals for participation in playback trials. Focal females were exposed to two successive treatments on each trial: one call series from her own pup that had been recorded 1 to 3 days prior, and one call series from a non-filial but similar-aged pup. The presentation order of filial and non-filial call treatments was changed between trials and balanced weekly and by individual. The non-filial pup on each trial was unfamiliar (i.e., from a distant (>85 m) harem) and selected from our call bank. PCA scores to evaluate the response strength of each mother to each treatment: Behavioural variables were pooled into a principal component analysis (PCA) with a composite score ...