Hollows for hornbills

A unique World Land Trust-backed project providing artificial nest sites is offering a lifeline to endangered Bornean birds left homeless by deforestation. The Trust’s José Rojo Martín explains how the scheme works and what we can all do to support it.

A unique World Land Trust project providing artificial nest sites is offering a lifeline to endangered Bornean birds, as José Rojo Martin explains.

Orangutans might have become the worldwide symbol of what habitat loss and degradation are doing to Borneo, but the country is also home to some astounding birdlife. Funded by donations to a new appeal by World Land Trust (WLT), saving two plots of rainforest in Kinabatangan will allow local partner Hutan to expand a critical nesting programme for eight hornbill species – a plan that Birdwatch readers can help make a reality. Studying the life of Malaysian Borneo was what drew Isabelle Lackman to the island – and protecting it is what made her stay.

“My dream had always been to research Borneo’s wildlife, but when we arrived more than 20 years ago to the Kinabatangan Floodplain we realised that conservation issues were too pressing – if we didn’t do something there’d be no wildlife left to study,” Isabelle says of her co-founding in

1996 of conservation organisation Hutan. “Since then, we’ve protected and restored these rainforests through land purchase and enlisted local women to plant thousands of trees. Wherever we look today, we see signs of how impactful this work has been; how key it is for it to continue.”

Continue the work must, because a history of deforestation at Kinabatangan has resulted in a tornapart landscape: islands of protected forest where wildlife faces a fate of genetic isolation. Having secured land for the Keruak and Pangi corridors in past years, Hutan now has a chance – with support from a new

WLT appeal – to expand the latter: two new properties, 10 acres in all. At stake is the opportunity to protect part of a landscape home to not just

215 iconic mammal species such as Bornean Orangutan and Borneo Pygmy Elephant but also 314 bird species, including eight of Asia’s 10 hornbill species.

The Critically Endangered Helmeted Hornbill, Rhinoceros Hornbill with its golden-yellow casque, the mohawksporting White-crowned Hornbill,

Black, Oriental Pied, Bushy-crested, Wreathed and Wrinkled Hornbills – Kinabatangan’s eight are in a world of their own, yet they all share an uncertain future if land protection does not continue at scale. Except for Oriental Pied Hornbill, populations

of all eight species across their entire distribution range are classed as NearThreatened, Vulnerable or worse on the IUCN Red List.

“When we surveyed hornbill populations specifically at Kinabatangan we realised that some of them really are in trouble, and it largely comes down to lack of natural nests,” Isabelle explains. “These birds can live up to 30-35 years and because of such a lifespan, what we see is aging individuals with fewer places to breed. The big risk is once this generation dies the population will not replenish and that’s what we’re trying to avoid, through a nesting programme this campaign could help us expand to new patches of forest at Kinabatangan.”

A home for hornbills

For Hutan, the first step was to assess the housing picture for Kinabatangan’s hornbills – an assessment, by extension, of the state of the landscape itself. Because these birds are unable to dig out their own tree cavities they need the rainforest to provide natural ones – and provide the rainforest did, for as long as humankind allowed it. In Malaysian Borneo, the intensive logging for timber decades ago decimated the floodplain’s primary forests: the big, living trees and the natural hollows that future generations of hornbills depend on. When Hutan gauged nest availability in the secondary forest that stands today, they found there were too few suitable options left. It was time to intervene. To give hornbills a home they could use, Hutan had to adapt its thinking to these birds’ remarkable home-making habits. The females that are sealed into the nest to incubate the eggs need large, ventilated spaces, while the males that forage and pass food through a small entrance need a branch to stand on. “And these birds can be picky,” Isabelle points out. “For instance, male Rhinoceros Hornbills will perch below the cavity to feed the female from there, while other species prefer a branch on top of the cavity. So you need a hollow, but also the right place for the male to sit.”

With this hornbill wishlist in mind, Hutan partnered with Dr Ravinder Kaur – a Malaysian hornbill researcher who later founded her own NGO, Gaia – and together they opted for a twopronged approach. First, they looked at how natural cavities in Kinabatangan’s forests could be retrofitted, with field visits leading to improvements including larger hollows, nest floors with better grip and trunk add-ons for males to perch on.

Next came artificial hornbill nests: having heard of pilot schemes in

Thailand, the Hutan team was inspired to go down this route. As Isabelle explains, Dr Kaur carried out tests to ensure all aspects key to nest design – temperature and humidity are the most crucial, size aside – added up to the perfect hornbill home.

Getting there required a fair bit of fine-tuning, but Hutan is already seeing positive results from the latest iteration: a marine plywood prototype coated with expanded polystyrene foam for insulation and fibreglass for weather endurance.

“We’ve had artificial nests being used by Rhinoceros, Bushy-crested and Oriental Pied Hornbills, and we’ve even seen young fledglings,” Isabelle says. “Now that this programme has been successful, we want to expand it. With support from donations to this campaign, the two properties we can now secure at Pangi are a start, and our goal is to continue saving land – reconnecting the landscape

and restoring the network of nests that hornbills once enjoyed in the Kinabatangan Floodplain.”

Swiftlet success

As Hutan seeks to stage a housing revolution for Kinabatangan’s hornbills, its work with another species illustrates the power of conservation to reverse a bird’s grim fortunes.

At Pangi, the target area of WLT’s new appeal, the Hutan has successfully rescued Edible-nest Swiftlets from a downfall brought about by a lucrative trade. Small as they are – bodies just 14 cm long, with blackish-brown backs set against lighter underparts – this swift species has spent centuries as the unwitting centre of a colossal industry. Demand for the solidified saliva nests, exported to China and beyond as a food delicacy, fuelled a harvesting boom in Kinabatangan going back to the 1300-1400s; a largely sustainable activity for most of its earlier history. “Indigenous people had for centuries a traditional, sustainable way of harvesting nests, but in the late 1990s, the state started tendering it to private companies,” Isabelle says. The shift, she adds, meant that the sustainability element of the trade – the care to ensure not to harvest nests where babies have yet to hatch or fledge – weakened. “The breeding process was disrupted and the population collapsed. By the time we launched our programme for this species in 2010, there were only 317 Edible-nest Swiftlet pairs at Pangi.”

Moved to intervene, Hutan negotiated with the Sabah Wildlife and Forestry Departments to bring the trade back to Indigenous people: the Sukau village communities who retained the expertise and had been heartbroken to watch swiftlet populations crash. Sustainable harvesting by local hands resumed, while 18 trained young villagers were hired by Hutan to guard the caves’ entrance 24 hours a day – theft attempts of chicks-hosting nests are “constant and rampant”, Isabelle says – and others tasked with monitoring the swiftlet population and patrolling the forest. Results followed shortly: from 2010’s 317 pairs at Pangi, Hutan this year counted more than 5,000. “With enough investment, we now believe this project has the potential to become self-funded as swiftlet numbers continue to grow,

given the sustainable revenues and ecotourism potential,” Isabelle says. “This is yet another example of how inclusive conservation doesn’t just benefit wildlife – it can also lay the foundations for a stronger local economy.”

Conservation ‘breaking point’

Much like everything else, humans included, the life of Borneo is having to adapt to 2021’s reality of a fragmented, degraded natural world. Kinabatangan’s orangutans are, according to Hutan, changing their diet and learning to be less territorial with each other to weather the shift to smaller, crowded forest patches.

For hornbills, the adjustment is no less steep and artificial nests can only go so far. As Isabelle points out, Kinabatangan remains a landscape “at breaking point” despite the progress seen so far with Hutan’s land purchases and talks with plantation owners to secure safe passage for wildlife. In the long run, the only option is to double down on these proven solutions, and drive them at scale. Some species, like Helmeted Hornbill, sorely need this conservation push to succeed in Kinabatangan and beyond: its rangewide populations are classified as Critically Endangered and decreasing, and sightings of pairs within Hutan’s target area remain very rare.

But if some of Kinabatangan’s bird residents lie on the brink, they can be brought back through Hutan’s triedand-tested approach since 1996. “We know how impactful conservation action can be because we’ve seen its results over the decades: the 460 acres we have already saved at the Keruak Corridor, the 150 or so acres we can save in total across the river at Pangi, the more than 52,000 trees our Indigenous restoration team has planted in the area,” Isabelle says. “Hornbills, swiftlets, primates, local people – a better future is possible for the rainforests of Kinabatangan. Let’s create it together!” ■

Helmeted Hornbill is classified as Critically Endangered due to the ongoing pressures of hunting and habitat loss.

Female hornbills, like this Helmeted, seal themselves into their nest cavities, leaving only sufficient space for the male to pass through food.

Securing sites in Kinabatangan’s rainforests will allow Hutan to provide artificial nests for all eight of Borneo’s hornbill species.

Rhinoceros Hornbill is listed as Vulnerable. Habitat destruction has led to the loss of the large trees the species requires for breeding, which in turn makes it easier for poachers to find the birds.

Edible-nest Swiftlet (above) is a conservation success story for Hutan, with the conservation organisation working with local communities to protect the species’ nests (below) from unsustainable trade as a food delicacy.