[MARMAM] New publication: Using vocal cues to assess arousal state of bottlenose dolphins
Dear MARMAM community, My co-authors and I are pleased to share our recent publication: Rachel Probert, Bridget S. James, Simon H. Elwen, Tess Gridley. 2023. Vocal cues to assess arousal state of bottlenose dolphins (*Tursiops *spp.) involved in public presentations. Journal of Zoological and Botanical Gardens 4(4): 711-727. https://www.mdpi.com/2673-5636/4/4/50# ABSTRACT: Emotions in animals may be expressed by arousal and understanding this often relies upon the monitoring of their behaviour. Under human care, animals’ arousal states may be linked to husbandry decisions, whereby animals may display arousal responses to scheduled events such as feeding and human interaction. Here, we investigate vocal correlates of arousal associated with public presentations of bottlenose dolphins (Tursiops spp.) in human care by comparing vocal production rates and characteristics between high and low arousal contexts. Elevated arousal during the day compared with overnight was characterised by increased signature and non-signature whistle production. High intensity broadband crack vocalisations were produced less than whistles during the day and did not correlate with increased arousal around presentation times. Three of ten dolphins increased signature whistle production before and/or after presentation sessions, indicating elevated arousal and variation in individual responses. Many individuals elevated minimum frequency and suppressed maximum frequency of signature whistles in a way that correlated with higher arousal contexts, indicating that these may therefore be good indicators of changes in arousal state. Overall, our study demonstrates that passive acoustic monitoring can provide a useful indication of arousal linked to husbandry decisions, and that individual variation in vocal responses, likely linked to personality, is important to consider. All the best, Rachel Probert -- *Rachel Probert* *PhD candidate, Marine Biology, Bioacoustics* Sea Search Research and Conservation, Muizenberg, Cape Town School of Life Sciences, University of KwaZulu-Natal, Westville Campus, Durban Cell: +27767831809 https://www.buymeacoffee.com/SeaSearch ___ MARMAM mailing list MARMAM@lists.uvic.ca https://lists.uvic.ca/mailman/listinfo/marmam
[MARMAM] New paper: Evidence of signature whistles produced by Indian Ocean bottlenose dolphins (Tursiops aduncus) in Mozambique
Dear MARMAM community, My co-authors and I are pleased to share our recent publication titled "Evidence of signature whistles produced by Indian Ocean bottlenose dolphins (*Tursiops aduncus*) in Mozambique" https://doi.org/10.1080/09524622.2023.2229290 ABSTRACT: Individually distinctive signature whistles are used by common bottlenose dolphins (*Tursiops truncatus*) during social interactions and to facilitate group cohesion. There is evidence from a few populations that Indian Ocean bottlenose dolphins (*T. aduncus*) also use signature whistles. We investigated this from a coastal resident population of *T. aduncus* in Mozambique. Video-audio data were collected during recreational swim-with activities over 12 years, where potential signature whistles were identified from 28 individuals. Of the 405 whistles documented, 75% were produced in SIGID bouts. Visual assessment of individual signature whistle contours demonstrated temporal stability for up to 8 years. Overall, most signature whistle types had upsweep frequency modulation and were emitted as multiloop whistles. Comparing all whistle contours to each other indicated low discrimination between individuals, with contours frequently categorised together. However, sex differences in the frequency characteristics of whistles were identified, with females whistling at lower frequencies than males. Our results indicate either a shared whistle repertoire or identity encoding with subtle contour features, requiring acute auditory perception and discrimination to decipher caller identity. More widespread geographic investigation into signature whistle use may demonstrate variation in acoustic communication systems for bottlenose dolphins, which are thus far not well understood. Best, Rachel Probert -- *Rachel Probert* *PhD candidate, Marine Biology, Bioacoustics* Sea Search Research and Conservation, Muizenberg, Cape Town School of Life Sciences, University of KwaZulu-Natal, Westville Campus, Durban Cell: +27767831809 https://www.buymeacoffee.com/SeaSearch ___ MARMAM mailing list MARMAM@lists.uvic.ca https://lists.uvic.ca/mailman/listinfo/marmam
[MARMAM] New publicaiton
Dear Colleagues, My co-authors and I are pleased to announce our recent publication. Probert R, Bastian A, Elwen SH, James BS, Gridley T (2021) Vocal correlates of arousal in bottlenose dolphins (*Tursiops* spp.) in human care. PLoS ONE 16(9): e0250913. https://doi.org/10.1371/journal.pone.0250913 Abstract: Human-controlled regimes can entrain behavioural responses and may impact animal welfare. Therefore, understanding the influence of schedules on animal behaviour can be a valuable tool to improve welfare, however information on behaviour overnight and in the absence of husbandry staff remains rare. Bottlenose dolphins (*Tursiops* spp.) are highly social marine mammals and the most common cetacean found in captivity. They communicate using frequency modulated signature whistles, a whistle type that is individually distinctive and used as a contact call. We investigated the vocalisations of ten dolphins housed in three social groups at uShaka Sea World dolphinarium to determine how patterns in acoustic behaviour link to dolphinarium routines. Investigation focused on overnight behaviour, housing decisions, weekly patterns, and transitional periods between the presence and absence of husbandry staff. Recordings were made from 17h00 – 07h00 over 24 nights, spanning May to August 2018. Whistle (including signature whistle) presence and production rate decreased soon after husbandry staff left the facility, was low over night, and increased upon staff arrival. Results indicated elevated arousal states particularly associated with the morning feeding regime. Housing in the pool configuration that allowed observation of staff activities from all social groups was characterised by an increase in whistle presence and rates. Heightened arousal associated with staff presence was reflected in the structural characteristics of signature whistles, particularly maximum frequency, frequency range and number of whistle loops. We identified individual differences in both production rate and the structural modification of signature whistles under different contexts. Overall, these results revealed a link between scheduled activity and associated behavioural responses, which can be used as a baseline for future welfare monitoring where changes from normal behaviour may reflect shifts in welfare state. Please feel free to contact me if you have any questions: rachelpr...@gmail.com Best regards, -- Rachel Probert PhD candidate, Marine Biology, Bioacoustics Sea Search Research and Conservation, Muizenberg, Cape Town School of Life Sciences, University of KwaZulu-Natal, Westville Cell: +27767831809 https://www.buymeacoffee.com/SeaSearch ___ MARMAM mailing list MARMAM@lists.uvic.ca https://lists.uvic.ca/mailman/listinfo/marmam
