Wat Chong Lom or Wat Sutthi Wata Wararam fronts the river mouth at Tambon Tha Chalom on the western side of the Tha Chin River. It was constructed during the Ayutthaya period, and the religious buildings in the temple have been beautifully renovated. Apart from the aesthetic qualities of the temple complex, the site is well-known amongst birders for its colony of Edible-nest Swiftlets Collocalia fuciphaga. The colony is located high up in the roof of the shrine of one of the temple’s founders, and is guarded at all times to stop thieves stealing the valuable nests - the main ingredient of ‘bird’s nest soup’ (for more “info” see below).

The colony has been using this building for thirty years, and some nests are harvested annually to pay for the protection of the colony and for tubs of mealworms used to feed very young swiftlets (see bottom photo) that are routinely found on the temple floor and are looked after until (hopefully) they fledge. Donations are very welcome from visitors of course.

(Samut Sakhon is located about 28 kms. from Bangkok along Highway no. 35, the Thon Buri-Pak Tho Highway. It is also accessible by train from the Wongwian Yai Railway Station in Bangkok.)

Edible-nest Swiftlet Collocalia fuciphaga
Wat Chong Lom, Samut Sakhon, Bangkok

The Edible-nest Swiftlet Collocalia fuciphaga is found throughout S E Asia and is renowned for the fact that the birds’ nests are used for making bird’s nest soup. During the breeding season, the salivary glands of this species expand to produce the special saliva for binding detritus together for building the nest, which is a shallow cup stuck to the cave wall. Nests which are ‘white’ and made purely or almost purely of saliva - like those of the Edible-nest Swiftlets above - are the most valued. When cooked, the birds’ nests have a gelatinous texture and in Chinese cuisine high medicinal and aphrodisiac qualities are ascribed to these nests. Scientific investigations reveal these nests to be high in protein with about 7% lime. Many consumers of bird nest soup report significant improvement in appetite. However, some others noticed excessive secretion of gastric acid that may cause acid reflux symptoms.

Nests are harvested from cave walls and there is increasing concern that over-harvesting is causing several species of cave swiftlets to become scarce. Bird nest merchants in southeast Asia (including Vietnam, Indonesia, Thailand) have started to raise and breed the swiftlets in house-like structures. They build the shelters to attract wild swiftlets to build nests in them. The “wrong” kind of nests are then destroyed along with the eggs inside. Over time, the selection process only leaves behind a colony of swiftlets that produce the right kind of nest for the trade. “House nests” are priced much lower than the “cave nests” due to the level of risks involved in the harvesting process of the latter. (Adapted from Birding India: Edible-nest Swiftlet)