Page 66 - BBC Knowledge - October 2017 IN

WILDLIFE
Otters

Tight-knit giant otter families –
here, overseen by mob leader Diablo (left) –
do everything together: they hunt, play
and sleep as a group, even sharing babysitting duties

brutes are hardly beautiful to most human eyes. Diablo’s family is the subject of the longest-running study
In all honesty they have faces only their mothers of giant otters, started by Frankfurt Zoological Society (FZS)
could love. in 1990. So you might think that we’ve learned pretty much all there
is to know about these charismatic mustelids. But Diablo has kept
DIABLO’S CLAN a few surprises for Charlie.
Charlie studies each of the lake’s giant otters in As he watches this first morning, he notices that Diablo’s family
turn. Ever since he filmed this family for Wildlife seems protective of its den, and it soon becomes apparent why.
on One a decade ago, he has wondered what Not two or even three, but six tiny cubs emerge. They are already
became of it – in particular, a youngster known a few weeks old, so must have been born in October. In Manu,
as Diablo. He was just a cub then, and Charlie giant otters usually bear two to four cubs, generally between
had witnessed his first swim. Had he survived April and July, so to find so many young at this time of year is
to adulthood? completely unexpected.
The pale ‘bib’
on each giant Giant otters have one key distinctive feature – Six cubs! Is that a record? Dr Rob Williams, who leads the FZS
otter’s throat is a creamy patch under the chin, research project, is intrigued. “It means that the family has produced
as unique and the shape of which is unique to two litters of cubs this year,” he says. “On a couple of occasions,
distinctive as each animal. Charlie had we suspected that this was happening, but we’ve never been able
a human fingerprint
memorised the pattern to prove it – until now.”
on Diablo’s throat; as he sees an The forest is often impassable in November, which is the rainy
otter swimming across the lake, season, so the researchers tend to visit Cocha Salvador several
he’s certain that he is looking at months later, when they usually expect to find two or three cubs.
the same individual. Charlie’s discovery suggests that the otters give birth to more young
Diablo is clearly now the than they had thought and that, by the time the zoologists arrive,
dominant breeding male of only two or three survive. “The cubs are almost certainly being
a large clan consisting of taken by caiman,” Rob muses.
himself and his mate Sophia,
two cubs from the previous SWIMMING LESSONS
spring, plus five other adults Over the next six months, Charlie films the cubs every day as they
and sub-adults. They all defer discover how to survive in a lake that’s home to 700 hungry caiman.
to Diablo – he’s the boss. First, they must learn to swim – essential, you might think, but
66
OCTOBER 2017