One nature group is keeping a watch on hornbills in Temengor to see how
logging is affecting the species.
THERE IS one place where Malaysia’s most endangered hornbill species can be
observed in the hundreds and thousands, and dozens of people flock there once a
year to see it.
It is nestled within haunting landscape – a dense blanket of jungle
interspersed with 172sqkm of lake. This large swathe of Temengor Forest Reserve
in Perak disappeared under water after the Temengor dam was constructed in 1978.
What remains are islands – the tips of submerged hilltops – surrounded by state
land where logging still takes place.
One spot, Pos Chiong, is located not far from a logging concession. And it is
where excited nature lovers gather in August and September, at dawn and at dusk,
atop a flat hill, to wait. Some have binoculars slung around their necks; others
stand at the ready, armed with notebooks, pens and cameras. Though everyone has
been through at least one dry run, when hundreds of plain-pouched hornbills
begin to descend from three different directions, flapping in a rotating “V”
formation, a few inevitably begin to panic.
Rare gathering: So far seen only in the northern part of
Peninsular Malaysia, plain-pouched hornbills have been observed to gather in
large numbers in Temengor forest reserve in Perak and Ulu Muda forest reserve in
Kedah. — Photo by Lim Tze Tshen
Presumably taking turns to enjoy the slipstream created up front, the moving
mass of birds can be overwhelming. It usually takes a couple of minutes for
volunteers to regain composure and remember everything they’ve learned. Once
they’ve gotten over the spectacle, the count begins – 10 ... 20 ... 100 ...
1,000 ... 3,000!
That last figure was the biggest number ever recorded during a single count.
It happened in 2008, the first year volunteers were invited to join the
hornbill-counting expeditions led by the Malaysian Nature Society (MNS), which
had up until then been sending out two- to three-man teams into the jungle to
make counts.
“Having more eyes and ears really helps,” says Yeap Chin Aik who heads the
nature group’s conservation division. “With just a two- or three-man research
team, we could only do surveys a few days every month. But now we have about 50
people doing counts spread over two months.”
The sheer size of the numbers observed led researchers to suspect that the
flocks probably constitute the bulk of Temengor’s population of plain-pouched
hornbills. Three thousand is a sizeable number, especially considering there is
thought to be a (decreasing) population of fewer than 10,000 mating individuals
worldwide.
The plain-pouched hornbill, which graduated from its listing as
“near-threatened” on the International Union for Conservation of Nature (IUCN)
Red List in 1988 to the more ominous category of “vulnerable to extinction” in
1994, used to be abundant in Toungoo, a town along the Sittang River in
south-central Myanmar. After the town’s forest cover was cleared for rice
cultivation, people stopped seeing the plain-pouched hornbill in its historical
stronghold, a testament perhaps of how intolerant the species is to forest
clearance.
The species is also found in west, south-west and south Thailand where
populations are estimated at over 1,000 individuals, though recent discoveries
of a roost containing 900 birds indicate that this number should be revised
upwards.
Yeap Chin Aik, head of the Malaysian Nature Society conservation
division, says the aim of the hornbill project is to gauge the impact of logging
in Temengor on bird population.
These figures show that Malaysia’s population of plain-pouched hornbills may
be the largest yet. Intriguingly, Malaysia did not even know it had the species
until sometime around 1998. Up until then, Malaysia officially harboured nine
hornbill species.
Even the Jahai, a sub-group of Peninsular Malaysia’s indigenous Semang
population which has long been established in the Temengor area, was unaware of
the differences between plain-pouched and wreathed hornbills, two
morphologically similar species referred to in native Jahai tongue as
sang
kor.
The mass flocking event was observed for the first time in 1992 and it was a
few years later that birdwatchers suggested that the birds might not be wreathed
hornbills. Subsequently, consistent observations of certain physical features
unique to the plain-pouched prompted the MNS Bird Conservation Council to accept
this as the tenth hornbill species in Malaysia.
Mysterious birds
Hornbills are one of Malaysia’s most recognisable birds but there is still
much that we do not know about them – for a number of reasons. If one wanted to
do a proper population study, it would take time and cost a lot. Often, there
are no open spaces with clear views of the sky, to enable a proper count.
In addition to that, looking for a hornbill nesting site is not easy. It
can’t be an easy task for hornbills either; they can’t excavate their own
cavities and must therefore prospect for homes by scouting for large trees with
suitable nesting holes.
“Some hornbills require certain conditions ... good insulation, the correct
hole size. Some are only interested in holes of a certain angle, whilst others
might prefer cavities at the knob of a fallen branch,” says Yeap.
Such requirements mean suitable trees are far and few between. To search for
them, MNS researchers initially replicated tried and tested methods employed by
Thai researchers – stand at a vantage point to spot for hornbills making
repeated flights across the forest, on the off chance that some might be
breeding pairs. It yielded limited success, so MNS eventually changed tactics,
paying local indigenous people for guidance to known nest sites in the
forest.
MNS now knows of 17 nesting sites belonging to six hornbill species within
the Belum-Temengor Forest Complex. With funding from Yayasan Sime Darby, they
will be setting up a camera at one of these sites to better study breeding
behaviours.
Yeap hopes the camera footage will shed light on the many gaps in our
knowledge – like how hornbills breed, when they breed and how long they breed
for.
“We definitely need to know a whole lot more about hornbills,” he says,
adding there is currently no one in Malaysia specialising in hornbill
research.
Plain-pouched hornbills were not known to exist in Malaysia until
the 1990s. — Photo by Lim Kim Chye
Even the crowd-drawing mass flocking events that begin around July before
peaking in August and September is to a large extent, a mystery. “Why July? We
don’t know,” says Yeap.
Some think that it has to do with the bird’s breeding cycle. Reports have
shown the species spend time nesting in Thailand between January and May, during
which time mating pairs would be geographically restricted. This is because the
female bird seals herself and her chick into the tree cavity, relying on the
male, who forages for food and feeds them through a small slit. Hornbill chicks
are thought to leave the nest at three months – perhaps this is when they start
departing Thailand for Temengor.
The Jahai have commented that hornbill arrivals coincide with the fruiting
season. Our understanding of the cyclical and seasonal fruiting patterns within
the Belum-Temengor forest is, however, incomplete, making clear correlations
difficult. It has also been suggested that moving in large numbers might prove
beneficial in terms of foraging efficiency.
Vital species
Whatever the reasons for mass flocking, the hornbill’s eating habits is
important in the shaping of plant diversity in our forest. Seed dispersal plays
a critical role in the maintenance and recovery of forests, and hornbills are
large frugivores capable of dispersing larger seeds.
Considering its ecological importance, and the fact that this might be the
world’s most important population of this endangered creature, the threats
hovering over plain-pouched hornbills are cause for alarm.
Selective logging practices which involve only harvesting trees of a certain
size pits loggers searching for large trees directly against hornbills searching
for suitable nest sites. It is therefore important to monitor how logging of
Temengor Forest Reserve, which is mainly a production forest, is affecting the
birds. This is why the annual MNS hornbill-count is important. So far, however,
records from yearly counts have revealed a fluctuating population trend, from
which no clear conclusions can be drawn.
The mass flocking of hornbills can be a major tourism
attraction for Temengor.
In 2004, just over 1,000 hornbills were counted in Temengor. This dropped to
under 200 in 2005, before rising to over 1,500 in 2006. The year 2007 saw
another drop to the low hundreds, before the amazing 2008 bumper year, where
over 3,000 were counted. In 2009, numbers dropped once again to below 100 but
rose to just below a thousand in 2010.
Explanations for these bouncy figures vary. Some think birds are altering
their flight path due to disturbance to the forest – land clearing by indigenous
people and commercial logging.
No one has a clear picture of what’s going on, which is why MNS preaches
caution. To protect the hornbill’s habitat, it has been campaigning to get
Temengor gazetted, in order to create a single transboundary protected area
spanning southern Thailand and northern Peninsular Malaysia. Similar campaign
efforts succeeded in getting the neighbouring Royal Belum State Park gazetted in
2007.
The Belum-Temengor rainforest complex is special. Comprising the Temengor
Forest Reserve, Belum Forest Reserve and the Belum Royal State Park, it is
266,170ha of contiguous forest cover. What’s more, the forest complex links up
with two other protected areas in southern Thailand, the Hala Bala Wildlife
Sanctuary and Bang Lang National Park.
Protecting plain-pouched hornbills is not just a matter of sentiment; the
birds have a lot of potential to bring economic benefits to the country. The
spectacular mass movements of these birds can be marketed as a tourist
attraction. MNS is currently working with the Tourism Ministry to promote bird
watching in Belum-Temengor.
