New Scientist – June 10 2017

NEWS & TECHNOLOGY
Lifeline for extinct
Galapagos tortoise
Sam Wong
A SPECIES of giant tortoise
unique to Floreana Island in the
Galapagos and considered extinct
since the 19th century could soon
be brought back from the dead.
Galapagos giant tortoises are
often divided into 15 species, 11 of
which survive today. The tortoise
populations on all the islands
were decimated after humans
arrived in the archipelago and
began loading them onto ships
for their meat. Sailors also
brought animals such as rats,
which can eat young tortoises,
and goats, which destroy the
reptiles’ habitat.
Tortoises were eliminated
from Floreana Island shortly
after Charles Darwin’s visit in
1835. Another species, the Pinta
Island tortoise, lost its last
remaining member, named
Lonesome George, in 2012.
But these species may not be
gone forever. Both Floreana and
Pinta tortoises have a saddleshaped
shell, allowing them to
raise their necks to reach higher
JUAN CARLOS MUNOZ/NATUREPL.COM
vegetation. In 2008, researchers
discovered a few tortoises living
around Wolf volcano on Isabela
Island that had saddle-like shells,
rather than the dome-shaped
shells usual on the island. DNA
collected from the saddle-shelled
animals suggested they were
descended from Floreana and
Pinta Island tortoises. It is thought
that tortoises were moved
between the islands on ships.
In 2015, biologists returned to
Wolf volcano to look for more
tortoises with Floreana and Pinta
ancestry. They carried out blood
tests on 144 individuals, then
lifted 32 promising candidates
onto a ship by helicopter and
took them to a captive breeding
centre on Santa Cruz Island.
–I’m not dead yet!–
Genetic tests suggested that two
of the tortoises may be purebred
Floreana tortoises – which might
imply that the Floreana species
isn’t actually extinct. Alternatively,
the two may have had very
recent purebred ancestry. Another
63 are thought to have Floreana
ancestry, but none appear to
descend from Pinta tortoises
(bioRxiv, doi.org/b733).
Conservation biologists
have begun a captive breeding
programme, with the aim of
returning these tortoises to
Floreana Island.
The Galapagos National
Park Service has already had
success with breeding tortoises
in captivity. There were just
15 Española Island tortoises left
by the 1960s. All of them were
brought to the breeding centre,
and more than 2000 bred
in captivity have now been
returned to the island.
It’s a “sensational opportunity
for conservation to save a
species that was thought to have
been lost forever”, says Axel
Moehrenschlager, chair of the
Reintroduction Specialist Group
at the International Union for
Conservation of Nature. “This
would be important for the
valuable ecological function
giant tortoises provide on a
landscape level.” ■
Woof! Vocal
synth creates
realistic barks
ROBOTIC canine companions are
getting an upgrade. Artificially
generated barks that match a robot
dog’s physical characteristics can stop
it falling into the uncanny valley.
As tech improves, robot pets are
set to become more popular. But they
will need to sound the part. Most
existing robo-dogs are programmed
to play pre-recorded woofs or growls
that rarely fit the robot’s outward
appearance, says Roger Moore at
the University of Sheffield, UK. He’s
developed a vocalisation synthesiser
that generates biologically fitting
sounds for land mammals of any size.
“You could dial up the body size to an
elephant and it would still generate
an appropriate sound,” he says.
When tasked with giving a voice
to MiRo – a robotic dog developed by
UK-based start-up Consequential
Robotics – Moore simply input the
dog’s body weight and let his
algorithms get to work.
Moore’s synthesiser models the
key parts of a mammal’s vocal system,
including the lungs, larynx and vocal
tract. The synthesiser then combines
values for each of those features to
create an acoustic wave appropriate
for an animal with that vocal system.
For MiRo, a relatively small pair of
lungs and short vocal tract produce
a high-pitched yap you would expect
of a small dog.
MiRo also responds to touch and
sound. Moore’s system allows its bark
to change to suit the interaction.
For example, if it is stroked, its bark
gets shorter and more expressive –
mimicking the change in airflow into
the lungs of a happy, excited dog.
Even a small change in MiRo’s mood
will create a noticeable change in its
bark, says Moore. He will present his
“Youcoulddialupthebody
size to an elephant and it
would still generate an
appropriate sound”
research at the Living Machines
conference in California in July.
Nathan Lepora at Bristol Robotics
Laboratory, UK, is impressed by the
technology and says it could be useful
for making realistic-sounding robot
companions for the elderly. Robots
are already being trialled as a way of
improving the lives of people with
conditions such as dementia. A cuddly
robotic seal called PARO is being used
by two NHS trusts in the UK and initial
research suggests that it relieves
stress, promotes social interaction
and improves fluency of speech.
Moore is now experimenting with
insect and dolphin vocal synthesisers.
He just needs the right robots to put
them in. Matt Reynolds ■
10|NewScientist|10June2017