The Adventure Club Phi Phi Island, Moo 7, Muang, Krabi, 81000

Birds’ Nests and Viking Cave, Ko Phi Phi

In and around the large limestone caves on islands, or near to the sea in Southeast Asia you can see some of the world’s fastest-flying birds – swifts, or swiflets (sometimes referred to as “sea swallows”). In Thailand 3 species of cave-dwelling swifts – the Edible-Nest Swiftlet, Pacific Swift and Black-Nest Swiftlet, build tiny white nests, the key ingredient in birds’ nest soup. One of the most expensive ingredients in the world, a kilo (between 90 – 120 nests) of top quality of raw birds’ nests costs between 100,000-120,000 baht ($3,000 to $4,000) around half the price of gold.

Particularly prized in Chinese culture due to their rarity, high nutritional value (containing high levels of calcium, iron, potassium, and magnesium) and exquisite flavor, birds’ nests are regarded as a delicacy, health booster, life prolonger and aphrodisiac, and are said to rejuvenate skin, clean out the digestive track, and cure lung cancer. Hong Kong and the United States are the largest importers of these nests, and a bowl of bird’s nest soup costs between US$30 to US$100 in HK.

The edible-nest swiftlets build their nests in the most inaccessible of places: high up (more than 10 metres) on the walls, ledges and ceilings of the limestone caves, or amongst the overhangs which abound on the Thai coast and its offshore islands. Thailand is the second largest exporter of birds nests after Indonesia, and Viking Cave, on Phi Phi Ley is one such well-known nesting site.

The nests themselves (about the size of a small egg and the hardness of a teacup) are made from saliva secreted by well-developed salivary glands which enlarge during the breeding season. These interwoven strands of saliva when exposed to air harden like cement or glue that hold the nest together and keep it attached to the vertical walls of caves or cliffs.

The nests are harvested by highly-skilled collectors who climb barefoot up flimsy bamboo scaffolding, bridges and rattan ropes, tapping as they go to ensure the bamboo is sound. The men use special knives and three-pronged tweezers (blessed by the cave spirits) to cut and pull the nests off the cave walls. Harvesting is dangerous work and is tightly controlled and regulated to protect the birds and make the sure the supply of bird’s nests is not depleted. Companies and their collectors hold exclusive government concessions to collect nests from specific sites, which is auctioned every 5 years and costs about THB 100,000,000 ($500,000 a year). The nests are so precious that they are protected by armed guards during the collection season, in order to prevent poaching. It is due to the presence of these birds nests that the Viking Cave is not open to the public.


Nests are constructed during the breeding season over a period of 35 days, starting around February – March. The swiflets build the nests during the night and go searching for food in the day providing the ideal opportunity for collectors to harvest the nests. This first harvest which focuses on collecting the nests before the female lays her eggs, generally produces the purest white, least contaminated and most valuable nests.

Out of instinct to maintain the species the swiflets start to build a second nest when they discover their nest is absent, meaning the second harvest is around one month later.

The third harvest is not for another 3 months (around August) since the third nest is where the eggs are laid and the baby birds hatch and grow.  After this harvest the cave is isolated until the next year.

If you join a boat trip around Phi Phi Ley be sure to take a look at the entrance to Viking Cave, and around the island in general for the bamboo scaffolding and ropes used by the collectors, and during the mating season for the tiny, fast swiflets performing acrobatic dives as they search for food. Contact us now to join one of Phi Phi Ley Tours.


About the Author
Andrew Hewett is the founder and owner of The Adventure Club. Resident of Phi Phi Island for 20 years. Amateur Photographer, experienced diver, passionate about the ocean.

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