The_Scientist_-_December_2018

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18 THE SCIENTIST | the-scientist.com


MIKE BOSSLEY

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tions provide an example of the impressive
imitative skills of dolphins in general.
“Dolphins are excellent mimics, both
physically and acoustically,” Mann says.
The results support this concept and are
“also consistent with the general finding
that dolphins learn such behaviors when
they are young.”
Based on the data, Bossley and his
colleagues suggest in the paper that the
mimicry illustrated by the spread of tail
walking behavior might help researchers
understand how wild bottlenose dolphins
in the area have learned to adopt a range
of foraging behaviors, from beating cuttle-
fish with their snouts to catching fish in
conch shells.
Mann, however, says she’s not con-
vinced by this argument because, unlike
foraging behavior, the tail walk has no

obvious biological function. “The context
of tail walking was not reported in the
study,” she says. “Was the dolphin alone,
in a group? What happened before and
after the tail walk?” To be absolutely sure
of the function of the behavior, much more
context for each occurrence is needed, she
says. Perhaps then it could reveal clues
about other learned behaviors.
One possible explanation is that the
animals have adopted tail walking as a
signal of some sort. “The behavior could
be used to show other dolphins that
the tail walker is exuberant or capable,
which could serve as either a sexual sig-
nal or one to improve the group cohe-
sion of the pod,” says Bernd Würsig, a
behavioral ecologist who studies whales
and dolphins at Texas A&M University
at Galveston and was not involved in the

study. That said, “I do not believe the
authors have indications for these [sig-
nals] in this case.”

Bossley agrees that there’s no evi-
dence in their study that the behavior
provides fitness benefits to the animals.
“I think the behavior is arbitrary because

CULTURAL FAD: This adult female dolphin,
known to researchers as Wave, appeared to
have learned the behavior from Billie.

Dolphins are excellent
mimics, both physically
and acoustically.
—Janet Mann, Georgetown University
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