Along the spine-jarring road that runs through this city on the South China Sea, in between the sparse, waterlogged shacks of corrugated aluminum and wood, colorful buildings have begun to sprout.
They tower over their low-slung surroundings with dollhouse facades, colored in baby blues, sunshine yellows and ruby reds.
Sukadana, a small coastal city in western Borneo, is in the midst of a building boom. But the new houses are not for people. They are giant birdhouses playing an all-day siren call through booming speakers to a small bird whose edible nests “” at almost $1,000 a pound “” produce a broth that is highly prized, and highly priced, in China.
“They actually look nicer than a lot of the real houses,” said Andrew Teixeira de Sousa, field director for the Gunung Palung Orangutan Conservation Program, which is active in the nearby Gunung Palung National Park. “But that’s just because there’s a lot more money going into those buildings.”
The bird “” called, appropriately enough, the edible-nest swiftlet “” makes its nest by regurgitating long strands of sticky saliva onto the wall of a cave or house, as the case may be. These strands harden into a woven cup, weighing on average about a third of an ounce, that provides a cradle for the birds’ young and hangs from the wall.
Many Chinese believe that these hardened cups, when married with broth, bestow special health benefits. Some Web sites claim the nests can help fight disease, aid blood flow, strengthen the body, moisturize the skin and even help mothers recover their youthful figures more rapidly after childbirth. One company advises women to feed their babies nest fragments dissolved in milk to “give the infant a flexible mind.”
Real or not, the supposed health benefits of the nests have allowed sellers to charge a premium price. Iskandar, a village official in Riam Berasap Jaya who like many Indonesians goes by one name, said a good quality nest that had the classical cup shape and was free of dirt and feathers could fetch $11 to $23.
Mr. Iskandar, a former illegal logger, shares a property line with a swiftlet house; he has many friends involved in the trade and is saving up for one of his own. Since most of the forests in the area have been bought up by palm plantations, he says, the logging business is not what it once was.
The edible bird’s nest has been in Indonesia for hundreds of years, but it wasn’t until the advent of the CD player that the boom really took off, said Lim Chan Koon, of the University of Malaysia, the co-author of The Swiftlets of Borneo.
Before then, people would venture into caves to gather the nests. “Some wise guy thought of using playback of the swiftlets’ vocalization to lure them into purposely built structures imitating the cavelike environment,” he said.
Once enticed inside, the swiftlets encounter an environment designed to keep them regurgitating comfortably. Small openings in the rear of the building allow them access but keep predators out. Holes allow air to circulate but keep crosswinds to a whisper.
There are large bird feeders, and open-face water tanks provide bathing and drinking water. Misters keep the temperatures inside cool despite the blistering daytime heat.
Getting started in swiftlet farming requires what is, for this part of the world, a significant amount of money. Mr. Iskandar said a medium-size three-story swiftlet house can cost about $16,000 “” a prohibitive sum for many.
Still, the houses keep going up. Almost every kink in the winding roads here reveals another. On some of the straighter stretches, the houses sit in clusters of threes and fours.
In the early morning and evening when the birds return from foraging, the jostling around the entrances seems like an avian freeway exchange “” a black roiling mass of thousands of birds, each entering and exiting faster than the human eye can track. And between the birds and the electronic calls, the chirping never stops.
Economists estimate the total value of the nesting trade ranges anywhere from tens of millions of dollars to anyone’s guess. “The bird’s nest industry is in the informal sector of Indonesia’s economy that is difficult to estimate,” said Fauzi Ichsan, a senior economist with Standard Chartered Bank.
But the unregulated industry is also raising concerns that Indonesian swiftlet farmers could be producing more than just nests. Indonesia is acutely sensitive to bird-related disease scares. Since 2003, H5N1, better known as the avian flu, has caused 146 deaths and fueled global fears of a pandemic, and the toll in Indonesia is the highest in the world, according to the World Health Organization.
Some are concerned that the increasingly dense networks of swiftlet houses could create disease flight paths for the avian flu, threatening both the local bird populations and potentially humans, as well. Almost as worrisome are the large water tanks inside each house that provide prime breeding sites for mosquitoes that could carry dengue fever and malaria “” two tropical diseases of particular concern in Borneo.
The profusion of bird droppings that cover the buildings and the surrounding areas is also a concern. “When it’s dry, the wind will carry any particles and germs in it, possibly causing various respiratory diseases,” said Trisasi Lestari, a physician and researcher in the public health department of Gadjah Mada University.
But on the roads around Sukadana, potential health concerns seemed secondary, and swiftlet house owners seemed more concerned with the flightiness of the birds themselves.
In Riam Berasap Jaya village, Budi sat in a sweltering room staring at a mostly blank closed-circuit television screen. A recording of bird calls screamed at high volume in the next room. It had been six months since his swiftlet house was finished, but only a few nests dotted the walls.
Luck, Mr. Budi says, plays as great a role as preparation in swiftlet farming. You see, he said with a sigh, you can entice an edible-nest swiftlet to a birdhouse, but you can’t make it nest.
Jeff DelViscio reported from Indonesia for The New York Times on a Gatekeeper Editors’ trip organized by the International Reporting Project (IRP). Mariamah Achmad contributed reporting from Ketapang, Indonesia.