In Go Cong District of Tien Giang Province nowadays, you might find a flock of salangane flying towards houses rather than the cliffs.
That’s down to a breeding project developed by Eka Vietnam, which aims to create an artificial environment in which salangane birds can build their precious nests.
Salangane are famous for producing edible nests known as yen sao in Vietnam. The nests, which have been exploited by humans since 16th century, are considered practically a magic medicine in parts of Asia.

The nests are said to help relax the nervous system and stimulate the reproduction system as well as brighten skin, slow the aging process and prevent the emergence of tumors. Legend has it that salangane nests were eaten daily by King Qin Si Huang in China and the famously virile King Minh Mang in Vietnam.
A kilogramme can be sold for $1,500 to $1,800 or even up to $3,000 in Hong Kong or Taiwan.

Dao Yen (Salangane Island) off the coast of Nha Trang in Khanh Hoa Province is home to a large population of the bird. Locals have been exploiting the nests for generations.

You need to be brave, cautious and on the ball for the job. It may be a lucrative business but hanging off the roof of a cave is a dangerous way to make a living and there have been fatalities in the past. Plus, the birds only naturally produce one nest a year.

So, that’s where Eka Vietnam steps in. By housing the breeding process, director of Eka Vietnam Le Danh Hoang, a 24 year old economics graduate from Ho Chi Minh City, hopes to transform salangane breeding in Vietnam.

Hoang has studied techniques for raising Salangane in Indonesia as well as Malaysia, Singapore, Thailand, Cambodia, Hong Kong and the US, before returning to Vietnam to found Eka Vietnam in 2005.

“It has been long supposed that salangane are living along the coast in central and southern provinces and make nests offshore on steep cliffs. But in fact, these birds can live in herds and make nests in the houses,‍ says Hoang.

The houses must be located near the natural habitat of the birds, plus it must be in the flight pattern of birds. The houses were created to make the birds feel at home with artificial chirpings, rain and temperatures. Houses cost VND60-80 million ($4,375). Owners don’t have to worry about feeding the birds as salangane catch insects for food.
The chairman of the Indonesian Association for Salangane Breeders, Doctor Elisa Nugroho, claims there is a 95 per cent success rate if the house is located in the right place and appropriate technologies are used. Birds raised in the houses can build up to four nests per year.

In Indonesia where there are more than 200,000 houses breeding salangane, one house could earn $70,000 a year.
A successful salangane house of 100sqm in Vietnam could produce 10kg of nests, worth around $15,000 profit per year
Eka Vietnam has worked on nearly 50 salangane-raising houses located throughout central and southern provinces including Danang, Quang Ngai, Binh Dinh, Phu Yen, Khanh Hoa, Ninh Thuan, Dong Nai, Ho Chi Minh City and Tien Giang, most of which are totally client-invested

The nests are actually made from the saliva that two parent salangane spit out. The bird nest with blood (huyet yen) is considered the most nutritious and thus is the most expensive.

In legend this was said to be the result of a couple of love exhausted salangane. The birds are a symbol of fidelity and chastity in Vietnam as they will never have second lover as they never fly into the wrong nest.

However, the red colouration is in fact the result of over exploitation, as by taking their nest it means the salangane have to produce another, resulting in the birds coughing up blood.