You can always tell otter experts by
a
certain pose they tend to strike,
explains Claus Reuther, a German
naturalist who visited Thailand last
week. He proceeds to demonstrate
by raising a cupped hand, holding it
up to his nose and taking a deep
sniff.
What on earth is he smelling?
Why, otter dung, of course.
''It's actually quite a pleasant smell,"
explains the heavily-bearded
Reuther, whom one suspects of
making a virtue out of necessity, ''a
mixture of honey and fish."
And you thought wildlife biology was
a glamorous profession ...
Actually, there are advantages to
being a member of this trade. For
instance, you get to study one of the
most charming animals on the planet.
Otters are not only cute and playful,
they are also extremely clever and
adapt quite easily to being around
humans.
You also get to tramp around
beautiful and isolated wilderness
areas, as a gathering of Asian otter
specialists did last week at the Huay
Kha Khaeng Wildlife Sanctuary.
There, another curious characteristic
of these mammal experts was
evident: They walked in the river
itself to avoid trampling on any clues
as they scoured the riverbanks for
telltale prints or, better yet, a precious
otter turd.
The researchers were in Thailand for
a workshop on methods of surveying
otter populations, and they picked a
good site to do it: Huay Kha Khaeng
is the only place in the world where
three separate species of this
intriguing animal are known to
co-exist.
But spotting otters is not easy.
Nocturnal creatures who inhabit
wetlands, river basins and coastal
zones, they tend to be somewhat
secretive and therefore elusive. So
otter researchers, like many other
types of wildlife biologists, usually
make do with studying their footprints
and their ''spraints" the scientific
(and polite) term for the animal's grey,
slimy droppings.
In fact, there is a surprising amount
of
data to be gleaned from spraints
because otters actually use
defecation as a form of
communication. They belong to a
family of mammals which includes
weasels, badgers, martens, mink
and, according to some
classifications, civets and mongoose
distinguished by the presence
of an
anal gland that soaks the faeces with
pheromones as a kind of scent
signal.
''All otters spraint, usually on rocks
around riverbanks. It's their most
conspicuous feature," explains Hans
Kruuk of the Institute for Terrestrial
Ecology in Scotland. ''They'll do it
as
often as 20 to 40 times per day,
scattered throughout their range. A
spraint basically tells other otters
who
is feeding here and so they
shouldn't waste time looking for food
in this area."
That's not all. According to Reuther,
director of Germany's Otter Centre,
spraints can inform other otters (and
any keen researchers nosing around)
about the animal's gender, its social
status for instance, if a male
is
resident in his home range or is a
non-resident or, if it's female,
whether it is ready to mate.
Unfortunately, because the frequency
of sprainting can vary according to
the seasons, they are not useful in
estimating the size of otter
populations. Instead, otter
researchers focus on studying the
distribution of otters where the
animal can be found and where it
can't.
In Asia, however, even such basic
knowledge is seriously lacking, says
Kruuk, who is considered one of the
world's foremost experts on otters.
''We need an Asian database," he
urges. ''We need to know what their
habitats are here, what constrains
their numbers, what sustains them
and what threatens them."
Out of more than a dozen otter
species worldwide, Thailand is home
to at least three: the common or
Eurasian otter (lutra lutra), the most
widely distributed of all the otters,
found from Ireland to Indonesia; the
smooth-coated otter (lutra
perspicallata), the largest of the Thai
otters; and the small-clawed otter
(aonyx cinerea), the smallest otter
in
the world and probably the most
common in Thailand.
There may also be a fourth species
the hairy-nosed otter (lutra
sumatrana) in southern Thailand
but
researchers know almost nothing
about it (except, presumably, that it
has a hairy nose). Indeed, it may live
in Huay Kha Khaeng, but nobody
even knows what its footprint looks
like.
''It is presumed to have [become
extinct] in Thailand," says Budsabong
Kanchanasak, an official at the Royal
Forestry Department's Wildlife
Research Division who is considered
Thailand's top otter expert. ''A single
specimen is known from a private
collection, reportedly bought from the
Sanam Luang market in Bangkok and
caught from the Mae Klong River in
western Thailand."
Even more perplexing than the lack of
information about otters, is an
apparent lack of interest in otters
in
Thailand. This adorable animal is
hugely popular in the West, thanks
largely to a book (later turned into
a
movie) called Ring of Bright Water
written by Gavin Maxwell, which
helped document the animal's friendly
and intelligent nature.
Budsabong and other Asian otter
researchers are also stumped as to
why Asians haven't taken to otters.
''It's probably because we have so
many other mammals, such as tigers
and elephants, which are much larger
and are part of our legends," she
speculates.
The Thai word for otters naak,
a
reference to the naga, a legendary
serpent would seem to indicate
that
it, too, is a part of Thai history,
but
Budsabong could not think of any
legends involving the animal. Rather,
she suspects the name was conjured
up by villagers who were reminded of
the mythical beast when they saw
otters with their long tails gliding
through the water.
For that is where otters seem most at
home. Adept and graceful swimmers,
they are, in Kruuk's words, ''symbols
of the wetlands", where they live atop
the food chain, eating fish, crabs,
shrimp, frogs and other aquatic
animals. In Europe, he reports, the
number of otter young produced
depends directly on the amount of
food the mother can catch, and in
colder climes they need a lot of
energy in order to navigate frigid
waters.
Otters, in other words, tend to have
voracious appetites, which makes
them highly unpopular with
fishermen, who see them as
competitors. The otters' intelligence,
which enables them to evade
defences, does not help matters:
They often bite through nets to get
into fish farms, and can outfox guard
dogs by splitting up into two groups,
with one serving as a decoy while the
other gorges on its catch.
''In Malaysia and Indonesia, farmers
consider otters to be pests because
they'll eat the fish in the rice paddies,
and destroy young rice plants by
rolling around on them," explains Nor
Burhanuddin of Malaysia's Wildlife
Conservation Division. They have a
similar reputation in Thailand, reports
Budsabong. In Narathiwat, she found
that farmers would simply try to chase
them away, but fish farmers in Samut
Prakan often shoot them, she says,
even though they are supposed to be
protected under the law.
The other main threats to otters also
come from humans. Otter habitat
shrinks with each wetland that is
dammed, drained or paved over.
Countless animals are run over by
cars, and in some regions such as
Siberia, otters are still hunted for
their
fur. Ingestion of toxic pesticides,
which caused the otter population to
crash in Europe, is no longer a
problem there according to Kruuk, but
may still be a serious factor in Asia.
Indeed, while otters seem to be
returning to parts of Europe where
they were formerly wiped out, in Asia
they are still on the decline. Ando
Motokazu, an otter researcher at
Osaka University, says otters are
now extinct in Japan although
there
are reports that a couple of sea otters
have migrated to Hokkaido from
Siberia and are on their last
legs in
Korea.
That makes sanctuaries like Huay
Kha Khaeng and Thung Yai
Naresuan all the more important.
Kruuk and Budsabong have carried
out a couple of studies in these areas
in an effort to understand the different
ecologies of the various otter species
and gain clues as to how they
interact.
It turns out that the small-clawed otter
feeds almost entirely on crabs, while
the smooth-coated species prefers
larger fish and the common otter
goes for just about anything. In terms
of habitat, the small-clawed otter
tends to inhabit small, shallow
waterways while his smooth-coated
relatives prefer swifter-running,
lowland water courses. The common
otter, meanwhile, is often found in
calmer, upstream waters, but last
week its tracks were also spotted
along the banks of a downstream
tributary to the Huay Kha Khaeng.
At first glance, this would seem to
indicate that the common otter is
highly adaptable, but the researchers
claim it is more likely to mean this
species is being driven to forage
more widely out of desperation,
perhaps as a result of competition
with the other species. Apart from its
hairy-nosed cousin, the common otter
seems to be faring the poorest in
Thailand and is listed as an
endangered species. The
small-clawed otter, meanwhile,
seems to be the most adaptable and
therefore the most abundant.
Although intriguing, such musings are
still only preliminary. Much more work
needs to be done, stresses Kruuk,
who hopes that Budsabong's work
can serve as a model for other Asian
researchers.
Eventually, these findings may be
useful in helping captive breeders to
re-introduce otters into areas where
they have been driven out. But that
is
a last resort, he says, and it only
works when the original threats to a
species have been resolved. ''First
we have to work on education," he
sighs.
As Budsabong concludes, ''otters
aren't only the symbols of wetlands,
they are also indicators of clean and
healthy river systems". Unfortunately,
there aren't many of those left in
Thailand.