White-bellied sea eagle



The white-bellied sea eagle (Haliaeetus leucogaster) is reputed to be Singapore’s largest common raptor or bird of prey, with a body length of 60 to 70 cm and a wing span of about 2 m.1 It is usually seen soaring above reservoirs and forested areas, or near sea coasts hunting for food.2 The bird’s nest can be found nestled within tall structures such as large emergent trees. It was reported that between 1987 and 1992, ten nesting sites of the white-bellied sea eagle were found on mainland Singapore, with up to five being active in a season.3

Description
An adult white-bellied sea eagle is identified by its grey upper body and white head, neck and underparts. Its long and broad wings are narrower at the tips. When seen from below while it is in flight, the eagle is observed to have white wing coverts covering its dark flight feathers, and a short, distinctive wedge-shaped tail that is white with black feathers at its end. When soaring, the eagle’s broad wings are held above its body in a distinctive, shallow “V” shape.4

The eaglet, on the other hand, has light brown feathers and a dull, cream-coloured head.5 When seen from below while it is in flight, the eaglet has pale brown wing coverts with dark flight feathers, and a pale-coloured tail with black feathers at its tip. The pale colouration gradually lightens to white as the young eagle matures to adulthood.6 Males and females share a similar appearance, although females generally tend to be larger.7 The call of the eagle is described as a loud goose-like honk.8 The eagle has excellent eyesight to help it spot prey from afar, and it uses its sharp talons to snatch and grasp prey from the waters.9

Reproduction
Forming sedentary mating pairs which are usually permanent, the eagles prefer to construct their nests on the tallest trees, usually emergent trees over 30 m tall. In Singapore, they have been observed to build nests on communication pylons, when these are taller than the surrounding trees. The nests are typically constructed with twigs upon a branch fork, and usually measure about 1.5 m across. These nests are used year after year, with repairs and addition of materials carried out annually at the start of the breeding season in September. The female usually lays two plain, chalky-white eggs. The incubation and hatching period has been reported to be from mid-October to early June.10

Diet
The eagles live on a primary diet of fish, sea snakes and crustaceans such as crabs. They have been observed dropping crabs from a height to break their shells before consuming them.11

Habitat and range
White-bellied sea eagles are commonly found along sea coasts, large rivers, lakes and reservoirs, and even on offshore islands. These eagles have also been spotted inland, far away from water bodies. Their typical range includes southwestern and eastern India, southeast Asia, south China and Australia.12

In Singapore, the eagles have been observed in locations such as the hill between Mount Faber and Kent Ridge, Sungei Buloh Nature Reserve, and the Istana.13 Offshore islands like Pulau Ubin, St John’s Island and Sentosa have also shown evidence of their presence.14

Singapore’s urban areas have been visited by the birds too. In 1989, stating that it was reported that a white-bellied sea eagle had built its nest on a satellite tower in Sentosa, and in 2008, two eagles fell into the balcony of a residential unit in Jalan Kayu after an aerial fight for territory. One of the birds died, while the other was treated for its injuries at the Jurong Bird Park.15 There were also sightings of the eagles around Changi Airport, posing a danger to aeroplanes.16

Instances where their habitats in urban areas were threatened have been reported, such as in 2012 when the nest of a pair of eagles stood in the way of a residential development in Chua Chu Kang. Fortunately, the developer decided not to cut down the tree on which the nest was built, until the fledging had matured and could fly off.17

White-bellied sea eagles do not  usually attack people unless they are in the eagle’s direct line of flight or are near their nesting grounds. However, there have been reported instances of such attacks. In 1990, a boy was chased by an eagle at MacRitchie Reservoir and two weeks later, national athlete Zhou Liye was attacked by an eagle which left three wounds in her left arm.18

Status
Since 2012, the International Union for Conservation of Nature and Natural Resources (IUCN) has categorised the white-bellied sea eagle as “Least Concern” in its Red List of Threatened Species. However, its global population is declining due to urbanisation and loss of habitat.19


Locally, the eagle is classified as “Common” based on a study conducted by Nature Society (Singapore) in 2011.20 Its numbers in Singapore have remained rather constant from 1996 to 2005, with an average of 13 eagles sighted per year.21 In March 2016, about 12 eagles were spotted in various locations around Singapore, such as Gardens by the Bay and Pasir Ris Park.22

Cultural significance in Singapore
The second series of Singapore’s currency notes, issued from 1976 to 1984, featured birds. The white-bellied sea eagle was depicted on the front of the highest denomination note – the $10,000 note.23 In a series of postage stamps released on 10 March 1963 showcasing Malayan birds and orchids, the eagle was featured on the $5 stamp, which was the highest denomination in the series.24 Since then, the eagle has made its appearance in many other series of Singapore stamps in various denominations.25 For instance, Singapore Post Limited (SingPost) released a set of stamps featuring native birds of prey on 21 September 2016, with the eagle featured on the 70-cent stamp.26


In 2002, the eagle was one of the shortlisted candidates in an unofficial poll conducted to select the national bird of Singapore. It garnered 236 votes, while the winner was the crimson sunbird with 400 votes.27

Variant names
English names: White-bellied sea eagle, white-bellied fish eagle.28
Scientific name: Haliaeetus leucogaster29
Chinese name: 白腹海雕 (Bai fu hai diao).30
Malay names: Helang siput,  lang laut, lang siput,31 burung hamba siput (bird that is a “slave of the shellfish”).32

The name “burung hamba siput” has its origins in a folklore about a bird that screams to warn shellfish to take cover when the tides change, or inform them when it was safe to emerge.33 The eagle was also thought to be the source from which the old name of the Malaysian state of Selangor was derived. The original name of Selangor was sarang lang laut, which means “nesting place of the sea eagles”. The name is a probable result of the white-bellied sea eagles that used to breed prolifically along the coasts of Selangor. Thus, the eagle now symbolises Selangor,  and was used for many years as its tourism logo.34



Authors

Timothy Pwee & Goh Lee Kim



References
1. Briffett, C. (1992). A guide to the common birds of Singapore. Singapore: Singapore Science Centre, p. 53. (Call no.: RSING 598.295957 BRI); Lim, K. S. (1997). Birds: An illustrated field guide to the birds of Singapore. Singapore: Sun Tree Publishing, p. 73. (Call no.: RSING 598.095957 LIM); Ida Bachtiar. (1990, February 17). Where eagles dare. The Straits Times, p. 1. Retrieved from NewspaperSG.
2. Ng, K. L. P., Corlett, R., & Tan, W. H. (2011). Singapore biodiversity: An encyclopedia of the natural environment and sustainable development. Singapore: Editions Didier Millet and Raffles Museum of Biodiversity Research, p. 219. (Call no.: RSING 333. 95095957 SIN)
3. Wells, D. R. (1999). The birds of the Thai-Malay Peninsula: Passerines (Vol. 2). London: Academic Press, p. 137. (Call no.: RSEA 598.0959 WEL)
4. Lim, K. S. (1997). Birds: An illustrated field guide to the birds of Singapore. Singapore: Sun Tree Publishing, p. 73. (Call no.: RSING 598.095957 LIM); Wells, D. R. (1999). The birds of the Thai-Malay Peninsula: Passerines (Vol. 2). London: Academic Press, p. 136. (Call no.: RSEA 598.0959 WEL)
5. Madoc, G. C. (1956). An introduction to Malayan birds. Kuala Lumpur: The Malayan Nature Society, p. 62. (Call no.: RCLOS 598.29595 MAD); Robson, C. (2015). Birds of South-East Asia. London: Christopher Helm, p. 122. (Call no.: RSING 598.0959 ROB)
6. Lim, K. S. (1997). Birds: An illustrated field guide to the birds of Singapore. Singapore: Sun Tree Publishing, p. 73. (Call no.: RSING 598.095957 LIM); Wells, D. R. (1999). The birds of the Thai-Malay Peninsula: Passerines (Vol. 2). London: Academic Press, p. 137. (Call no.: RSEA 598.0959 WEL)
7. Gan, W. M. J., & Lau, A. (2005). Birds seen at the Istana. Singapore: Suntree Media and Singapore Environment Council, p. 54. (Call no.: RSING q598.095957 BIR); Wells, D. R. (1999). The birds of the Thai-Malay Peninsula: Passerines (Vol. 2). London: Academic Press, p.137. (Call no.: RSEA 598.0959 WEL)
8. Lim, K. S. (1997). Birds: An illustrated field guide to the birds of Singapore. Singapore: Sun Tree Publishing, p. 73. (Call no.: RSING 598.095957 LIM)
9. Ng, K. L. P., Corlett, R., & Tan, W. H. (2011). Singapore biodiversity: An encyclopedia of the natural environment and sustainable development. Singapore: Editions Didier Millet and Raffles Museum of Biodiversity Research, p. 219. (Call no.: RSING 333. 95095957 SIN); Briffett, C. (1992). A guide to the common birds of Singapore. Singapore: Singapore Science Centre, p. 53. (Call no.: RSING 598.295957 BRI)
10. Madoc, G. C. (1956). An introduction to Malayan birds. Kuala Lumpur: The Malayan Nature Society, p. 63. (Call no.: RCLOS 598.29595 MAD); Wells, D. R. (1999). The birds of the Thai-Malay Peninsula: Passerines (Vol. 2). London: Academic Press, p. 138. (Call no.: RSEA 598.0959 WEL)
11. Madoc, G. C. (1956). An introduction to Malayan birds. Kuala Lumpur: The Malayan Nature Society, p. 63. (Call no.: RCLOS 598.29595 MAD); Briffett, C. (1992). A guide to the common birds of Singapore. Singapore: Singapore Science Centre, p. 53. (Call no.: RSING 598.295957 BRI)
12. Wells, D. R. (1999). The birds of the Thai-Malay Peninsula: Passerines (Vol. 2). London: Academic Press, p. 136. (Call no.: RSEA 598.0959 WEL)
13. Wee, L. (2000, June 4). Take a peek. The Straits Times, p. 8. Retrieved from NewspaperSG; Gan, W. M. J., & Lau, A. (2005). Birds seen at the Istana. Singapore: Suntree Media and Singapore Environment Council, p. 54. (Call no.: RSING q598.095957 BIR)
14. Lim, K. S. (2009). The avifauna of Singapore. Singapore: Nature Society, p. 219. (Call no.: RSING 598.095957 LIM)
15. Sea eagle picks satellite tower on Sentosa for nest. (1989, September 14). The Straits Times, p. 25; Sua, T. (2008, January 16). The eagles have landed – on a Jalan Kayu balcony. The Straits Times, p. 31. Retrieved from NewspaperSG.
16. Sim, R. (2013, May 20). Changi keeps fowl-ups to a minimum. The Straits Times, p. 1. Retrieved from NewspaperSG.
17. Chua, G. (2012, April 1). CDL protecting eagles nesting on site. The Straits Times, p. 19. Retrieved from NewspaperSG.
18. Khoo, P. (1990, February 14). Eagle attacks runner at MacRitchie Reservoir. The Straits Times, p. 2. Retrieved from NewspaperSG.
19. International Union for Conservation of Nature and Natural Resources. (n.d.). Haliaeetus leucogaster. Retrieved 2016, October 30 from The IUCN Red List of Threatened Species website: http://www.iucnredlist.org/details/22695097/0
20. Nature Society (Singapore) Bird Group Records Committee. (2011). Checklist of the birds of Singapore. Retrieved 2016, September 30 from Nature Society Singapore website: https://www.nss.org.sg/documents/Singapore%20Checklist%202011%20edition.pdf
21. Lim, K. C., & Lim, K. S. (2009). State of Singapore’s wild birds and bird habitats: A review of the annual bird census, 1996–2005. Singapore: Bird Group, Nature Society, p. 210. (Call no.: RSING 598.095957 STA)
22. Nature Society Singapore. (2016). Singapore raptor report: Spring migration, March 2016. Retrieved 2016, September 30 from Nature Society Singapore website: https://www.nss.org.sg/report/57ab4c80-7Singapore%20Raptor%20Report%20Mar16.pdf
23. Monetary Authority of Singapore. (2016). 2nd series – the bird series currency notes (1976–1984). Retrieved 2016, September 30 from Monetary Authority of Singapore website: http://www.mas.gov.sg/currency/circulation-currency/notes.aspx; New $10,000 note. (1980, February 2). The Business Times, p. 12. Retrieved from NewspaperSG.
24. Birds and orchids on new Singapore stamps. (1963, February 1). The Straits Times, p. 11. Retrieved from NewspaperSG.
25. Wee, Y. C., Tan, W. K., & Wang, L. K. (2011). One for the birds: Singapore stamps & money. Singapore: Tan Wee Kiat, p. 37. (Call no.: RSING 769.5695957 WEE)
26. Singapore Post Limited. (2016, September 20). SingPost issues birds of prey stamp set [Press release]. Retrieved 2016, November 10 from SingPost website: https://www.singpost.com/sites/default/files/news_pdf_file_upload/2016/10/pr20160920.pdf; Leow, A. (2016, September 20). Local birds of prey featured in new SingPost stamp set. The Straits Times. Retrieved from Factiva via NLB’s eResources website: http://eresources.nlb.gov.sg/
27. Chew, H. M. (2015, November 2). Is the crimson sunbird Singapore’s national bird? Er… not official yet. The Straits Times. Retrieved from Factiva via NLB’s eResources website: http://eresources.nlb.gov.sg/

28. International Union for Conservation of Nature and Natural Resources. (n.d.). Haliaeetus leucogaster. Retrieved 2016, October 30 from The IUCN Red List of Threatened Species website: http://www.iucnredlist.org/details/22695097/0
29. Lim, K. S. (1997). Birds: An illustrated field guide to the birds of Singapore. Singapore: Sun Tree Publishing, p. 73. (Call no.: RSING 598.095957 LIM)
30. Yong, D. L., & Lim, K. C. (2016). A naturalist’s guide to the birds of Singapore. Oxford: John Beaufoy Publishing, p. 35. (Call no.: RSING 598.095957 YON)
31. Yong, D. L., & Lim, K. C. (2016). A naturalist’s guide to the birds of Singapore. Oxford: John Beaufoy Publishing, p. 35. (Call no.: RSING 598.095957 YON); Madoc, G. C. (1956). An introduction to Malayan birds. Kuala Lumpur: The Malayan Nature Society, p. 63. (Call no.: RCLOS 598.29595 MAD)
32. Yong, H. S. (Ed.) (1998). The encyclopedia of Malaysia: Animals (Vol. 3). Singapore: Archipelago Press, p. 43. (Call no.: RSING 959.5003 ENC)
33. Yong, H. S. (Ed.) (1998). The encyclopedia of Malaysia: Animals (Vol. 3).  Singapore: Archipelago Press, p. 43. (Call no.: RSING 959.5003 ENC)
34. Ponnampalam, A. (2000, September 5). A national bird for Malaysia? New Straits Times; Ponnampalam, A. (1996, August 20). Tales behind towns with bird names. New Straits Times. Retrieved from ProQuest via NLB’s eResources website: http://eresources.nlb.gov.sg/




The  information in this article is valid as at October 2016 and correct as far as we can ascertain from our sources. It is not intended to be an exhaustive or complete history of the subject. Please contact the Library for further reading materials on the topic.

 

Subject
White-bellied fish eagle--Singapore
Wildlife
Eagles--Singapore
Science and technology>>Zoology>>Birds
Haliaeetus--Singapore
Nature>>Animals