On our way through Kumai on the way to meet the boat for our awesome orangutan trip, I noticed that there was a large number (like hundreds, maybe thousands) of loud, squawking birds flitting through the air all around the town. Jenny also noticed that there were several strange, tall, concrete buildings with very, very small windows. We pondered the meaning and purpose of these strange sights, but were too overwhelmed with orangutan anticipation to give it much thought.
On the boat on the way back, as we approached Kumai and saw its strange skyline from the water, it suddenly clicked in my brain: these buildings and all of the birds everywhere are basically a factory farm for bird's nests that are to be made into soup. I had randomly watched a documentary on these nests but didn't make the connection right away.
Bird's nest soup is a Chinese delicacy made from bird's nests made from the saliva of cave swifts. A bit creepy, but it's a majorly huge industry and the bird's nests are wildly expensive. The soup is supposed to have all sorts of health benefits, from libido stimulation to immune system boosting.
The nests used to be collected from Indonesian caves where the birds naturally nest, but now that demand is so high for this luxury product that towns all over Indonesia, including Kumai, have devised a way to produce these nests in these giant concrete buildings. The birds are attracted by birdsong CDs, then enter the buildings through those tiny windows and then build their nests in the rafters. The nests are collected, then they are picked clean of feathers and other impurities using tweezers, molded into the desired shape, packaged up and sold at exorbitantly high prices, particularly to Hong Kong. The resulting soup can cost $30-100 per bowl, depending.
Here's a not-particularly-thrilling, but interesting video that shows you the inside of the bird houses.
Ya learn something new everyday, eh?