The greatly valued delicacy called the “edible-nest”, found in a number of Asian countries comes from few specific types of birds, and is picked from the habitat of only certain species of Swiftlets. Those special swiftlets all belong to the Collocaliini tribe of the Apodidae (Swift) family. What makes this particular type of nest edible and legendary is its unique natural component: the solidified saliva of the male swiftlet. It is common for people to confuse a swiftlet with a swift. It is likewise easy to confuse, amid the different swiftlet birds, the particular species that are producing those edible-nests. A high number of exported nests are located in Indonesia and Malaysia. Furthermore, since those two countries are composed of countless islands, it is important to clearly be able to point on a map the exact location of both natural and man-made habitats where the nests are collected. For these reasons, I thought relevant to make an article dedicated to the etymology and the mapping of all harvested edible-nests.

Map Asia - SwiftletsSources: created using information collected from various
documents mentioned in the bibliography.

Distinction between the Swifts and Swiftlets

        The Swift birds (Apodidae) are a taxonomic family consisting of 19 genus, including the Collocalia genus of swifts that was once a catch-all for different subcategories of swiftlets. However, number of them have been moved (though not by all authors) to be placed under the genera of Aerodramus (Boles, 2005).

        The four species remaining under the Collocalia genus are: the C. Troglodytes (Pygmy swiftlet), C. Dodgei (Bornean swiftlet), the C. Esculenta (Glossy swiftlet) that counts two subspecies–the C.E. Marginata (Grey-rumped swiftlet) and the C.E. Natalis (Christmas swiftlet), there is the C. Linchi (Cave swiftlet), under which one can find the four following subspecies: C.L. Dedii, C.L. Ripleyi.

        A swiftlet makes its nest with the male’s solidified saliva, and some species use other materials in the process of building the nests. The highest quality nests are the white-nest of the Aerodramus fuciphagus of the genus Aerodramus, which is only composed of cemented saliva. According to producers and consumers, this is the best quality nest to be used when preparing bird’s nest soup. The A. fuciphagus bird is small, only 12 cm in length, it is dark brown and it has a slightly forked-tale. Another highly harvested nest are the black-nest of the Aerodramus Maximus and of Aerodramus Unicolor. The black-nests are only made from the strand of their gummy saliva (no straw, feathers, or twigs). The nests built by the swiftlets of the genus Collocalia are of lower quality, since those birds use moss and other natural resources from their environment. On the other hand, a swift does not use its saliva to construct its nests.

        There was an international conference held in Kuala Terengganu, Malaysia in June 2011 called International Conference & Training on Swiftlet Ranching 2011 (ICOTOS). The conference was organized by the Faculty of Agriculture & Biotechnology, Universiti Sultan Zainal Abidin (UniSZA), and it was a place to share expertise and explore the challenges of the swiftlet ranching industries [1].

The edible-nest builders

        Even though the Apodidae (Swift) family contains 4 tribes, 19 genus, and around 109 species and countless subspecies, only birds in one of the 4 tribes that are making nests out of solidified saliva: the Collocaliini Tribe, which keeps 4 genus under its wings, of which only two of them are trafficked for their edible-nests: the genus Aerodramus and the genus Collocalia.

        In both Aerodramus and Collocalia genus, the nest is built with the saliva of a male swiftlet. However, what makes the Collocalia less attractive to nest-collectors than the Aerodramus is that in a Collocalia swiftlet nest, saliva is not the only ingredient. The Collocalia nests are considered inferior quality. In the case of the C. Esculenta a kind of string-like grass is attached to the surface of the spits before it becomes solidified (Tsang, 2008). In a nest made by C. Linchi, it is mostly built out of stringy vegetation and saliva. As for the C. Dodgei and C. Troglodytes, they are not going to be mentioned in this research, due to the materials (thick saliva and some moss) used in nest making that is unattractive to edible-nests traffickers.

         On the other hand, the Aerodramus counts 29 species, which only five of them are producing this highly wanted edible-nests only made out of solidified saliva: the A. Fuciphagus, A. Maximus, A. Unicolor, A. Francicus, and A. Germani. The nest of the first one is the most commonly harvested and consumed all over Asia. As for A. Maximus and A. Unicolor, their nests are also greatly appreciated by their consumers, as they are the only two species constructing a black colour edible-nests (Sankaran, 1998). In the case of the red ‘blood’ edible-nests, the nest is usually available from the coasts of Thailand [2]. It is the rarest and the most pricey of all nests. Accordingly to various sources, the red ‘blood’ nest could be made by most of the five edible-nests swiftlets if the phenomenon of oxidation in some of the more humid zones is possible.

Sources: created using information collected from various
documents mentioned in the bibliography.

‘Swiftlet’ in other languages

        I believe that by looking at the translation of the species into other languages is not only interesting, but it can also lead to further information, or understand the importance of those species in the countries where this language is spoken.

Latin:               Aerodramus.
English:           Edible-nest Swiftlets. Synonym: Swallow birds
Gray Swiftlet, Andaman Grey-rumped or German’s Swiftlet
French:            Hirondelles, Martinets.  Nids d’oiseaux comestibles.
Salangane à nid blanc, S. des Andaman, S. à croupion brun ou S. de German
Spanish:           Salangana Nidoblanco
German:           Weißnestsalangane
Japanese:        つばめのす or  ジャワアナツバメ
Chinese:          金丝燕 (Swiftlet),雨燕 (Swift).

        As the greatest eaters of those nests are Chinese, it is important to mention its name in simplified Chinese: “zhăo wā jīn sī yàn” (爪哇金丝燕) referring to the main type of birds producing the heavily exported edible-nests to China (via Hongkong), and “yàn wō” (燕窝) describing the edible nests in general. The Chinese literal translation means “swiftlets of Java”, which offers a very interesting insight on the edible-nest swiftlets, referring to the history when Chinese were purchasing the edible-nests from Java in Indonesia, to import them to mainland China for the consumption of the Chinese elites (Avibase). I think it is important to highlight that both the Aerodramus Fuciphagus and the Aerodramus Maximus are found on the island of Java (Indonesia).

        I first started to make diagrams for my personal reference, since it was becoming somewhat confusing for me to differentiate all those terms that have been changing over the years. Then, I decided to share those diagrams within my articles, to make the information more accessible to all types of audiences.

        At the beginning of my research, it was quite difficult to situate myself into this whole new world: the world of the swiftlet birds, which I knew nothing about, besides that some Asians were eating a soup made of a bird’s nest. Not only this was a difficult task because I have no background in ornithology, but also due to the  changeable terms used to refer to this specific over-exploited bird species, and highly trafficked, for its naturally produced solidified saliva edible-nests.

        ‘Aerodramus’ is the recent attribution for its former name: Hirundo. The five species under the genus Aerodramus that are producing edible-nests mainly with their solidified saliva have been assigned under the genus Collocalia for centuries. It is once the swiftlets were correctly assigned under the genus Aerodramus that some of them saw the ending of their name (specie) slightly altered, and others only changed the genus attribution.

‘Swiftlets’ mapped by the etymology

        There was also the scientific name Hirundo fuciphaga that was found during the research, but this is apparently an unacceptable term to design the Aerodramus fuciphagus (del Hoyo and Collar 2014) was previously placed in the genus Collocalia, and respectively split as C. fuciphaga and C. Germani, suggested by Sibley and Monroe (1990, 1993) [3]. The edible-nest swiftlets live all within the tropical and subtropical regions of South Asia and South East Asia. An older name found to label this Aerodramus specie is C. Fucivora (nomen oblitum).

        The production of edible-nests is a highly lucrative business, which motivates bird-farmers to produce fake nests to satisfy the rising demand of edible-nest products for its health virtues. Surprisingly, most buyers cannot tell the difference between a real and a replica. Until now, this (illegal?!) activity has been concentrated in Indonesia and Singapore, and Malaysia for the fake red ‘blood’ nests. Once harvested, the nests will be transported to the world’s biggest buyer, China– transiting through and being partly consumed in Hongkong. Is this ‘fake’ product an alternative to saving the birds’ declining population?

        Below are the major documented changes in the names of edible-nest Swiftlets, followed by the different names they have been attributed:

HAL_Aerodramus only3Sources: created using information collected from various
documents mentioned in the bibliography.

        The information for this section was collected from the IUCN Red List, BirdLife Factsheet, Handbook of the Birds of the World, and also from some other readings mentioned in the bibliography.

A. Fuciphagus : According to The Fauna of British India (1885), the Collocalia fuciphaga (now known as Aerodramus Fuciphagus) species would have only been recorded in Ceylon–now Sri Lanka– and Burma–now Myanmar–, since 1862 [4]: Aerodramus fuciphagus(del Hoyo and Collar 2014) was previously placed in the genus Collocalia and split as C. fuciphaga and C. Germani following Sibley and Monroe (1990, 1993).
Synonym: Edible-nest Swiftlet, Collocalia Germani (Oustalet, 1876)

A. Maximus : Aerodramus maximus (del Hoyo and Collar 2014) was previously placed in the genus Collocalia as C. maxima.
Synonym: Black-nest Swiftlet, Collocalia maxima (Hume, 1878)

A. Unicolor : Aerodramus unicolor (del Hoyo and Collar 2014) was previously placed in the genus Collocalia.
Synonym: Indian Swiftlet, Collocalia unicolor (Jerdon, 1840)

A. Francicus : Aerodramus Francicus (del Hoyo and Collar 2014) was previously placed in the genus Collocalia as C. francica. Synonym: Collocalia francica (Gmelin, 1789)
Synonym: Mascarene Swiftlet, Mauritius Swiftlet (English), Salangane des Mascareignes (French).

A. Germani : It is divided into two subspecies: A.G. Germaniand A.G. Amechanus, was formerly considered to be conspecific with the edible-nest swiftlet, but is now often considered to be a separate species. A.F. Germani occurs in the Malay Peninsula, central Thailand, coastal Vietnam, and Cambodia, Hainan Island, northern Borneo and parts of the Philippines

        There are six subspecies of the Aerodramus Fuciphagus bird producing high quality the edible-nests, which is one of the most expensive food on the planet. These six subspecies will often be mentioned in the following articles of this research on the edible-nest swiftlets.

A. f. Fuciphagus is the nominate subspecies found in Java, Bali, and the Western Lesser Sunda Islands, in Indonesia.

A. f. Inexpectatus is found in Andaman and Nicobar Islands, which belongs to the Union Territory of India, and is vagrant to Burma (Myanmar), near the Bay of Bengal in the Andaman Sea.

A. f. Dammermani is found in Flores (one of the Lesser Sunda Islands of Indonesia), which is known from only a single swiftlet specimen.

A. f. Micans is found in Eastern Lesser Sundas (Sumba, Savu) and in Timor, in Indonesia.

A. f. Vestitus is the species found on Sumatra and Borneo (islands of Indonesia), and sometimes considered to be a separate species, also known as the brown-rumped swiftlet. It was documented by René Lesson, a French surgeon, naturalist, ornithologist and herpetologist, who published about this subspecies in 1843. Recently, BBC News published an article on those birds, denouncing the “house swiftlets” that are dominating the skyline in the port of Kumai, a city in the southern tip of Indonesian Borneo.

A. f. Perplexus is found on Maratua Archipelago, which is off eastern Indonesian Borneo. [5]

       Collocalia : Collocalia Linchi (Sibley and Monroe 1990, 1993) was split into C. Linchi and C. dodgei by Moyle et al. (2008) but this treatment is not followed by the BirdLife Taxonomic Working Group, because their study fails to take account of the other taxa in the Linchi complex, namely C. l. Ripleyi from Sumatra and C. l. Dedii from Bali, and relied on a small sample size. All four subspecies of C. Linchi differ diagnosable in size, so no change to their taxonomic treatment is warranted until the complex is reviewed as a whole (IUCN Red List).

C. Linchi (Horsfield & F. Moore, 1854), or cave swiftlet, is found in Indonesia and Malaysia on Madura, Bawean, Nusa Penida and Java. It is a woodland species and nests in caves (Birds of India, 2013). There are four subspecies of the C. Linchi that have been described from 1854 to 1986: the Dedii (Somadikarta, 1986) found in Bali and Lombok and the C.L. Ripleyi (Somadikarta, 1986) found in the Barisan Mountains and on Sumatra (Chantler et al., 2014).

C. Esculenta (Linnaeus, 1758) is found in Brunei Darussalam; Christmas Island; India; Indonesia; Malaysia; Myanmar; New Caledonia; Papua New Guinea; Philippines; Singapore; Solomon Islands; Thailand; Timor-Leste; Vanuatu.

C. Dodgei (Richmond, 1905) which is also called the Bornean swiftlet is found in Sabah—Malaysian Borneo.

Conclusion

        Although there are several tribes, genus and species under the Apodidae family, not all are considered as swiftlets. The swiftlets main specificity is the nest made of the male’s solidified saliva. The other types of swiftlets are making their nests with other natural resources, which are unappealing to humans for its consumption. The biggest concentration of the Swiftlet birds is in Asia is located in Malaysia, Indonesia and India–Andaman & Nicobar Islands. The most commonly naturally harvested nest, and considered as the best quality nests are the Aerodramus Fuciphagus and the Aerodramus Maximus. As for the swiftlets living in man-made habitats, they are usually produced in Indonesia, Malaysia, Vietnam and Thailand. Then comes the fake nest produced in Indonesia, Malaysia and Singapore. Is the A.F. Fuciphagus (or the “Java Swiftlet” in Chinese) and the A.F. Vestitus from Sumatra & Borneo the most harvested because they are the earliest swiftlet species studied?

        Nowadays, are swiftlets in their natural habitat using echolocation more wanted than the farmed swiftlets now living in a concrete house? How does this man-made habitat influencing the swiftlets’ populations?

—————————–

[1] International Conference & Training on Swiftlet Ranching 2011 (ICOTOS)

[2] Banyan Bird Nest

[3] Birds of India (2013). Edible-nest Swiftlet. link 1,   link 2

[4] The Cyclopaedia of India and of Eastern and Southern Asia (1885). Commercial, Industrial, and Scientific. Products of the mineral, vegetable, and animal kingdoms, useful arts and manufactures. Morrison and Gibb, Edinburgh, Printers to her Majesty’s Stationery Office. By Surgeon General Edward Balfour, Third Edition. London. Bernard Quaritch, 15 Piccadilly. p.787

[5]  Boyle, Joe (27 Jan 2011). “Welcome to Indonesia’s bird nest soup factory town”. BBC news.


SOURCES:

On-line


Publications

Boles, Walter E. (2005): A New Flightless Gallinule (Aves: Rallidae: Gallinula) from the Oligo-Miocene of Riversleigh, Northwestern Queensland, Australia. (2005) Records of the Australian Museum 57(2): 179–190.

Chantler, P. & Boesman, P. (2014). Cave Swiftlet (Collocalia linchi). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.) (2014). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved on May 10, 2015).

K.C. Tsang, Amy Tsang (2008-03-01). “Glossy Swiftlets at Fraser’s Hill”. Bird Ecology Study Group. (C. Esculenta).

Sankaran, R. (1998). The impact of nest collection on the Edible-nest Swiftlet (Collocalia fuciphaga) in the Andaman and Nicobar Islands. Report to IUCN. Sálim Ali Centre for Ornithology and Natural History. Coimbatore, India.  

Worthy, Trevor H.; Tennyson, A.J.D.; Jones, C.; McNamara, J.A. & Douglas, B.J. (2007): Miocene waterfowl and other birds from central Otago, New Zealand. J.Syst. Palaeontol. 5(1): 1-39.

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