12 THE SCIENTIST | the-scientist.com
Notebook
NEWS AND ANALYSISNOVEMBER 2019Crossing
Species Lines
F
rom a small inflatable boat in the
Rangiroa atoll in French Polyne-
sia, Pamela Carzon got her first
glimpse of the “strange” trio of marine
mammals she’d been told about: a
bottlenose dolphin mother (Tursiops
truncatus), her seven-month-old calf,
and another young cetacean that was
slightly smaller and looked to be not a
bottlenose dolphin at all, but a melon-
headed whale (Peponocephala electra).
It was April 2015, and Carzon and a
colleague at the Marine Mammal StudyGroup of French Polynesia, a nongovern-
mental organization dedicated to whale
and dolphin conservation, were out for
the NGO’s annual photo-ID survey, very
much hoping to find animals that a for-
mer collaborator had seen while diving
in the region the previous November.
“[T]he sea was very calm, and there were
many dolphins around,” Carzon, also a
PhD student at the Center for Island
Research and Environmental Observa-
tory (CRIOBE) in French Polynesia and
the École Pratique des Hautes Études in
Paris, recalls in an email to The Scien-
tist. “It took us maybe two minutes to
spot them: the dark calf was easy to spot
among the bottlenose dolphins.”The mother, dubbed ID#TP25 by
the researchers, was known to toler-
ate divers and boats, and that April day
she approached the inflatable with both
calves. Carzon grabbed her underwater
camera and slipped into the water. “I
was able to get good underwater foot-
age and to sex both calves,” she says.
ID#TP25’s natural calf was a female;
the second calf was male. “I also noticed
that both were ‘gently’ pushing each
other [in order] to remain under the PAMELA CARZON, MARINE MAMMAL STUDY GROUP OF FRENCH POLYNESIADOLPHIN ADOPTION: A female bottlenose dol-
phin in the South Pacific has been sighted with
both her own calf and another young cetacean
identified as a melon-headed whale.