Male dolphins whistle to maintain key social relationships

Date:
March 24, 2022
Source:
University of Bristol
Summary:
Allied male bottlenose dolphins maintain weaker yet vital social
relationships with whistle exchanges, researchers have found.



FULL STORY ========================================================================== Allied male bottlenose dolphins maintain weaker yet vital social
relationships with whistle exchanges, researchers at the University of
Bristol have found.


========================================================================== While male dolphins are known to use physical contact such as gentle
petting to connect with strongly bonded allies, new findings published
in Current Biology today, show they rely on less time-demanding vocal
exchanges to remain connected with weaker allies.

The scientists, with colleagues from an international suite of
universities, used nine years of acoustic and behavioural data from a
dolphin population in Shark Bay, Western Australia, to assess how male
dolphins reinforced and maintained their valuable alliances.

Lead author Emma Chereskin, from Bristol's School of Biological
Sciences, said: "Many animals, including humans, use tactile contact,
touch, to strengthen and reaffirm important relationships. But as the
number of close social relationships increases, so too do the demands
on the time and space available for relationship maintenance through
physical contact. Male bottlenose dolphins form strategic, multi-level alliances, and we wanted to know how they maintained multiple alliance relationships in large groups." By following groups of affiliated males,
and documenting their physical and acoustic behaviour, the research
team was able identify the different ways that these males bonded with
each other.

Senior author Dr Stephanie King, also from Bristol, said: "We found
that within the core dolphin alliances, strongly bonded allies engaged
in more affiliative contact behaviour, such as petting and rubbing,
while weakly bonded allies engaged in more whistle exchanges. This
illustrates that these weaker but still key social relationships can
be maintained with vocal exchanges." In the social bonding hypothesis,
Robin Dunbar posited that vocalisations and language evolved as a form
of 'vocal grooming' to replace physical grooming, as increasingly large
group sizes placed impossible demands on the time available for physical contact behaviours. However, tests of this hypothesis in non-human
primates suggest that vocal exchanges occur between more strongly bonded individuals that engage in higher grooming rates, and thus do not provide evidence for replacement of physical bonding.

"Our findings provide new evidence that vocal exchanges can serve a
bonding function" Chereskin said, "but more importantly, and in line
with the social bonding hypothesis, that vocal exchanges can function
as a replacement of physical bonding, allowing allied male dolphins to 'bond-at-a-distance'. This evidence in support of the social bonding hypothesisoutside of the primate lineage raises exciting new questions
on the origins and evolution of language across taxa." The study was
funded by The Branco Weiss Fellowship -- Society in Science and the
National Geographic Society.


========================================================================== Story Source: Materials provided by University_of_Bristol. Note: Content
may be edited for style and length.


========================================================================== Journal Reference:
1. Emma Chereskin et al. Allied male dolphins use vocal exchanges to
"bond
at a distance". Current Biology, 2022 DOI: 10.1016/j.cub.2022.02.019 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2022/03/220324122518.htm

--- up 3 weeks, 3 days, 10 hours, 51 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1:317/3)