HORNBILLS AS ONE OF THE INDICATORS OF STABLE FOREST: Its diversity, ecological balance and sustaibility. Easy just protect the forest, no logging, no poaching, well manage and control, educating public, politician, business people and related government officers.

Tuesday May 1, 2012

Tracking hornbills

By NATALIE HENG
star2green@thestar.com.my

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.