This paper was published in Hornbill Natural History and Conservation vol. 3: 28-31, 2022
Bee Choo Strange1 * and Tony O’Dempsey2
1 Hornbill Research Foundation, Bangkok, Thailand & IUCN SSC Hornbill Specialist Group
2 Nature Society (Singapore)
*Corresponding author: Bee Choo Strange (bcngstrange@gmail.com)
Background
Three species of hornbill have been recorded in Singapore: Oriental Pied Hornbill Anthracoceros albirostris, Rhinoceros Hornbill Buceros bicornis (locally extinct), and Black Hornbill Anthracoceros malayanus (recent record). The Helmeted Hornbill Rhinoplax vigil historical record in Singapore is considered doubtful (Poonswad et al., 2013). Other species of hornbills recorded such as Bushy-crested, Great, Narcondam, Northern Red-billed, Trumpeter, Southern Ground, Wreathed and the White-crowned are considered escapees from captivity.
The Oriental Pied Hornbill (OPH) ranges from northern India, south Nepal, Bhutan, southeast Tibet to south China, and across Southeast Asia to Java and Bali. The OPH is a forest edge species occurring from coastal lowlands up to 700 m in elevation. This species is found in parks, plantations, wooded areas and near mangroves. Considered as medium size, the male is about 70–85 cm (700–900 g) and the female 60–65 cm (500–800 g) in length, with the male having a larger casque (Poonswad et al., 2013).
The renowned naturalist, Alfred R. Wallace, recorded this species in Singapore in 1855 and it was probably still in Singapore in the 1920s; however, there are no breeding records. Gibson-Hill mentioned that there was no record of hornbills in Singapore in the 1950s (GibsonHill, 1950). A small population recorded on the main island of Singapore in the late 1960s to late 1970s are presumed escapees. Some individuals were recorded in Pulau Ubin since 13 March 1994; they were believed to be visitors from Malaysia and the first local breeding was observed at Pulau Ubin on 26 April 1997 (Wang and Hails, 2007; Lim, 2009).
The breeding season of the OPH in Singapore generally starts from December and ends in March or April. Each clutch consists of one to four eggs, but usually only one to three chicks will fledge successfully (Teo, 2012). A paper (Ng et al., 2011) presented at the 5th International Hornbill Conference, held in Singapore from 22nd to 25th March 2009, documented camera surveys of five nests of wild Oriental Pied Hornbills in Pulau Ubin over four breeding seasons between 2005 and 2009, and one nest in the southern part of Bukit Timah Nature Reserve from 2008 to 2009 of a captive pair taken from Jurong Bird Park. The nests in Pulau Ubin were in natural cavities of Durio zibethinus trees and in artificial nest boxes, and 14 breeding cycles were recorded over four years. In the southern part of Bukit Timah Nature Reserve, two breeding were observed. Out of the 16 cycles, a total of 51 chicks hatched. The observations showed that the mean number of eggs laid in the wild was 3.3 and number of chicks fledged was 1.8 giving an average fledging success of 55%. Most of the chicks that were lost were due to cannibalism and infanticide.
In order to encourage wild hornbills to breed, more than 20 artificial nest boxes were installed all over Singapore from Pulau Ubin in the east to Sungei Buloh Wetland Reserve in the west (Cremades and Ng, 2012). The population has subsequently increased significantly throughout Singapore. In 2012, the population of OPH in Singapore was estimated to be between 75-100 individuals, with 19 nesting pairs recorded, of which 10 pairs were nesting in Pulau Ubin (east), two in Changi (east), two in the Istana (central), and one each in Turf City (central), Sungei Buloh (west), Seletar (north), MacRithchie (central), and Pasir Ris (east). The number of progeny in 2012 was estimated to be between 35 and 60 (Cremades and Ng, 2012).
Methods
In order to find out more about the current distribution of the OPH in Singapore, the first author downloaded eBird (https://ebird.org), iNaturalist (https://inaturalist.org) and other records from the Global Biodiversity Information Facility (GBIF) portal (GBIF.org 2022). There were 5177 occurrence records of OPH from Singapore in GBIF, of which 4533 are from eBird and 569 are research-grade observations on iNaturalist. As sightings prior to 2010 were considered to be very sparse, 4901 records ranging from 2010 to 2021 (including 4311 eBird and 518 iNaturalist records) were chosen for analysis. The sighting records were segregated into a selection of time periods and a kernel density filter was applied to each to create a series of sighting density maps that illustrate the dispersal of the Oriental Pied Hornbills from 2010 to 2021. Seven sighting density maps were generated for the periods 2010-2015 inclusive and one for each year from 2016 to 2021 (Figure 1).
Results and Discussion
The maps (Figures 1) show how the OPH has spread in Singapore over the past 12 years and that the dispersal of the hornbills are in areas near the reintroduction sites, with more sightings in the eastern part of Singapore. A pair of captive OPH from Jurong Bird Park was chosen to be bred in an artificial nest box in the southern part of Bukit Timah Nature Reserve for two breeding cycles in 2009, resulting in three chicks fledging (Cremades et al., 2011). It is of particular interest to note that subsequent sighting records from 2010 to 2021 did not show any OPH in the forests, and no hornbills were reported in the Central Catchment Nature Reserve and Bukit Timah Nature Reserve. Poonswad et al. (2013) indicated that the preferred habitats of this species are forest edges, open woodlands, coastal and riverine scrub and cultivation. We can speculate that this species may disperse further in the future, if their survival and dispersal in Singapore is encouraged by planting of food plants in various parks and gardens. We note, however, that the increased dispersal of OPH denoted on the maps may be partly due to increased reporting and records by observers on eBird and iNaturalist in recent years, and this needs to be studied and corrected for observer effort in different areas in future studies. To find out more about the dispersal and estimate the current population of the OPH in Singapore, a citizen science project was started in February 2022 in collaboration with Nature Society (Singapore), for which a part-time researcher was hired. Dr. Yong Ding Li of the Nature Society (Singapore), Dr. Rohit Naniwadekar of the Nature Conservation Foundation (India), and Assoc. Prof. Dr. George Gale of the King Mongkut’s University of Technology Thonburi (Thailand) provided advice about survey methodology and information to collect. The survey is underway and will help better understand hornbill distribution and abundance in Singapore.


Acknowledgements
We would like to thank Dr. Yong Ding Li, Dr. Rohit Naniwadekar and Assoc. Prof. Dr. George Gale for their invaluable advice. Mr. Evan Landy has been very helpful in setting up the transect survey grids and communicating with over 90 volunteers and assigning them their transects. Thanks also to Mr. Morten Strange, Dr. Shawn Lum, Dr. Jessica Lee and Mr. Lim Kim Chuah of the NSS bird group who have helped with this project. The base habitat map is derived from A High Resolution Map of Singapore’s Terrestrial Ecosystems (Gaw LY-F, Yee ATK, Richards DR, 2019). This project is funded by the Nature Society (Singapore).
References
Cremades M, Lai HM, et al. 2011. Re-introduction of the Oriental Pied Hornbill in Singapore, with emphasis on artificial nest. The Raffles Bulletin of Zoology Supplement 24: 5–10.
Cremades M and Ng SC. 2012. Hornbills in the City: A Conservation Approach to Hornbill Study in Singapore. National Parks Board, Singapore. Gaw LY-F, Yee ATK, Richards DR. 2019. A high-resolution map of Singapore’s terrestrial ecosystems. Data 4(3): 116. https:// doi.org/10.3390/data4030116
GBIF.org. 2022. Oriental Pied Hornbill GBIF records. Downloaded on 16 May 2022 https:// www.gbif.org/occurrence/search?taxon_ key=2475991&gadm_gid=SGP
Gibson-Hill CA. 1950. Ornithological notes from Raffles Museum, No. 14, Annotations, Addenda & Corrigenda to the Singapore Checklist. Bulletin of the Raffles Museum 23: 132–183.
Lim KS. 2009. The Avifauna of Singapore, Nature Society, Singapore.
Ng SC, Lai HM, et al. 2011. Breeding observations on the Oriental Pied Hornbills in nest cavities and in artificial nests in Singapore, with emphasis on infanticide-cannibalism. The Raffles Bulletin of Zoology Supplement No. 24: 15–22.
Poonswad P, Kemp A and Strange M. 2013. Hornbills of the World: A Photographic Guide. Draco Publishing.
Teo R. 2012. Special Ecology Feature: Conserving Hornbills in the Urban Environment. A Centre for Urban Greenery and Ecology Publication City Green #4, 130–135.
Wang LK and Hails CJ. 2007. An Annotated Checklist of the Birds of Singapore. The Raffles Bulletin of Zoology Supplement No. 15.

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kris
I just found a young dollarbird in the garden.. It seems to have left the nest too early and cannot fly yet. How am i to keep and feed it for a few days untill it can fly.???
Raja
March 20 is world sparrow day!
CHIRP FOR SPARROWS!
TWEET FOR SPARROWS!
TEXT FOR SPARROWS!
http://www.youtube.com/watch?client=mv-google&hl=en-GB&v=MQiq8FHrG_0&gl=US&nomobile=1
Iwan
We have a small pond in our garden surrounded by trees and steep bedrock. The other day we saw a heron flying over and attempting to land – I guess to try to eat our small stock of fish. We managed to frighten it away before it landed, and have since installed trip wires around the pond in order to dissuade the bird. The amount of shelter around the pond means that a heron would have to land practically vertically. Does anyone know whether these birds have the agility to hover and land in this way, or do they always need a “glidepath” in order to land successfully?
Khng Eu Meng
Today, at the former Bidadari Cemetery, there was a buzz about a sighting of a Grey Nightjar (Caprimulgus jotaka). I heard some birders say this nightjar isn’t commonly seen in Singapore. After some hunting, we spotted it asleep on a tree branch, some 15 m above ground. This was rather interesting as my previous encounters with nightjars have been on either terra firma or on low branches.
Is this perching so high up the tree normal or is it unusual? I have posted a photo of it on my Facebook Timeline: https://www.facebook.com/photo.php?fbid=10151125012234135&set=a.108191464134.96538.617499134&type=1&theater
Jess
Bird Sanctuary At Former Bidadari Cementry
1)Which is the best spot in Bidadari cemetery for bird watch?
2)Where this bird usually resident at?
3)What are some of the rare bird species that can be found at Bidadari?
4)Where is the particular hot spot for the hornbills, eagles, kingfishers and some of the rare migratory bird?
5)Which part of Bidadari are richest in it wildlife?
6)Can you name me the 59 migratory bird species found?
YC
Why not search the website using the word ‘Bidadari’ to obtain the information you need. There should be sufficient info in past postings to satisfy you.
Firdaus Razak
Hai, I just want to ask did anybody had an experience bring bird from oversea via MasKargo? Did the bird will stress at high altitude?
Arjun
I heard this interesting bird call in a forest, and recorded it. Could anyone help me identify it?
http://www.youtube.com/watch?v=9uubzo1wdbU&feature=youtu.be
Chung Wah
Hi, I am new to bird photography! Could anyone advise a good pair of binoculars to get for this hobby?
YC
Try this Facebook… https://www.facebook.com/groups/394479540610099/
I am sure there would be someone willing to advise.
Geam Liang
I ‘acquired’ a female Blue-crowned Hanging Parrot 5 days ago – was in a public place when the bird flew overhead hit the wall and dropped right in front of me dazed. I picked it up, it appeared unhurt but could not sustain it’s flight. I have since constructed a fairly large ‘cage’ for it, about 4ft x 2fx x 2ft and placed it there last night. I temporarily placed her in a normal bird cage until I had completed the build.
From what I have read up, it’s a fruit, seed and insect feeder and also nectar, flower buds. It’s doing as well as it can on bananas, papaya, jack-fruit (didn’t touch the grape) and seeds (black and white sunflower and other smaller ones). It loves to bathe so I’ve gotten it a tray and from what I read it’s important to keep things clean as it easily succumbs to infection.
Does anyone else have any useful experience and sharing on it’s upkeep? I suspect this bird is an escapee – as far as I can read up, it’s not common, if at all, found in Georgetown, Penang where I am. I’m also not optimistic that it can survive if I were to set it free – assuming it can sustain it’s flight and not go crashing down and if there were dogs/cats around that would be the end of it.
I can attach some pictures but not sure how to do this…
thanks.
Lee Chiu San
The blue-crowned hanging parrot, even though very closely related to the lovebirds, is a nectar feeder. You would raise it the way you raise a lorikeet – which is a messy process. And because you are mixing batches of food for just one little bird, whereas I used to do it for about half a dozen pigeon-sized lorikeets each morning, I don’t know how you are going to get the portions down to manageable sizes. Anyway, here goes, with my recipe for feeding big lories. You can adjust the proportions down accordingly for your little bird.
The staple diet would be a couple of slices of soft fruit (papaya, apple, grapes, even though I am surprised that you said the bird would not eat any) and a mixture of cooked rice sweetened with nectar mix.
How to make nectar mix? Go to a pharmacy and get a can of food for invalids or infants. I use Complan, but I am sure any good baby formula would do. I usually make up enough to fill a beer mug, but there is no way you need that amount for a day’s feeding. If in doubt, make the mixture thinner, not thicker. Birds cannot digest baby formula that is too thick. If it is too thin, they simply have to consume more to get the required amount of energy. Then to this mug, add half a teaspoonful of rose syrup. Also stir in about a cup of cooked rice, well mashed up.
In the case of your bird, I suggest that you pour this lot into an ice-cube tray, freeze the mixture, and defrost one cube to feed it each day.
Now, you said that this bird eats sunflower seeds. This is most unusual for a blue-crowned hanging parrot. Are you sure that this is actually the species you have? Could it be possible that you have actually got a pet lovebird that escaped? There are so many different artificially-created breeds of lovebirds in so many colours that you might have been mistaken.
If you actually have a lovebird, feeding is much simpler. Just go to the nearest pet shop, buy a packet of budgerigar or cockatiel seed of a reputable international brand, and offer it to the bird. You can supplement this with a couple of slices of fruit each day, and that will be all. Plus of course fresh water and a piece of cuttlefish bone to nibble on.
Lee Chiu San
About nectar feeding birds. I forgot to add that feeding nectar is messy, and it goes rancid very quickly in our tropical weather. Feeding containers have to be removed and thoroughly cleaned at the end of each day. The birds also splatter the mixture and wipe their beaks on perches and the bars of the cage. All my lories and lorikeets used to be housed in outdoor aviaries which were hosed down daily.
If Geam Liang does not think the bird will survive if released, I really hope that it is a case of mistaken identity, and that you have a lovebird, rather than a blue-crowned hanging parrot. In our part of the world, all available lovebirds are domestically bred, take to captivity readily, and are easy to feed with commercially available seed mixtures. Yes, and being domestic pets, they would not survive if released.
Geam Liang
Thank you Chiu San for your inputs. Thus far, bananas and papayas work well. I’m not sure why it did not take to grapes – will try again. Am I supposed to peel it? I didn’t the last time, basically skewered a couple of grapes to a satay stick and positioned it as I did for the sliced and skinned papaya and peeled bananas.
I have yet to try rice and certainly not nectar but will try out your concoction – have half a mind to go to a pet shop to see if they carry nectar for birds. The ice-cube freeze method is a good one, will try that. I might be mistaken on the sunflower seeds… not touched but it did eat the much smaller roundish, mixed colored seeds. Will remove the sunflower seeds.
I’m sure it’s a female blue crowned hanging parrot.. it sleeps like a bat every night.
Lee Chiu San
When feeding local birds which are unfamiliar with imported fruits such as grapes, it helps to split the fruits to expose the edible parts. As to your remark that the bird sleeps hanging upside down like a bat, yes, that is the way blue-crowned hanging parrots sleep.
Geam Liang
Thanks… I need to think like a bird – yup. She has probably not seen a grape much less know that it’s edible, unless the previous owner has fed her with grapes… even then… Today she’s done pretty well making the most of the banana and all of the papaya plus quite a bit of seeds. Will try the baby food + mashed rise + rose syrup.
Will regular honey do instead of rose syrup?
Thanks.
Lee Chiu San
About making nectar to feed birds. Most aviculturalists do not use honey for two reasons: 1. It is expensive and does not seem to give any added benefits. 2. Honey is made by bees, and the composition varies wildly. Some honeys are also known to cause fungal infection in birds.
If you do not want to buy a huge bottle of rose syrup just for one tiny bird, there are cheaper alternatives. The first is plain table sugar, though most don’t seem to like it very much.
What many birds will accept quite readily as a sweetener is condensed milk – the type with sugar that coffee shop owners use.
Many, many birds have a sweet tooth (or should I say sweet beak?) Besides the usual suspects of lories, lorikeets, sunbirds and hummingbirds, for whom it is an essential part of the diet, nectar mixture is readily consumed by mynahs, leafbirds, fairy bluebirds, barbets, doves, parrots of all kinds, and a whole host of other species.
Geam Liang
I tried the condensed mild, placed in in a small bottle cap.. only the ants showed interest. Am I supposed to dilute it? I didn’t =( I took you advice and refrained from honey. Have yet to find Rose Syrup from the shelves of TESCO… will try to mix the baby food + mashed rise + rose syrup/sugar syrup this week…
David Thackray
Can anyone help me identify a bird I saw in Singapore last week. Size of a smakll dove or thrush. Dark metallic back. Grey breast with red throat, chest.
BESG
Any images?
Emily Koh
Lately I bought a bird feeder which I fill with 4parts water n 1 part white sugar. Sunbirds come regularly to drink and they are really lovely to watch. May I know if it is bad for them to feed on this? Previously they would sometimes pierce and drink from my potted flowers
Emily Koh
Lately I bought a bird feeder which I fill with 4parts water n 1 part white sugar. Sunbirds come regularly to drink and they are really lovely to watch. May I know if it is bad for them to feed on this? Previously they would sometimes pierce and drink from my potted flowers.
Ken Sng
Hi Friends,
I need help in identifying these 13 birds which i’ve published in a public album on Flickr.
https://www.flickr.com/gp/81819728@N00/y8ws5B
They are numbered 1-13 so if you know what they are please reply with number and name .
I’m doing a personal project to shoot 100 different birds in SG.
Thanks very Much !
Mahadevi Bhuti
One of best souce for the bird watcher’s enjoying knowledge about ornithology
Martin Nyffeler (PhD)
Dear Sir / Dear Madame,
I am a Senior Lecturer in Zoology at a University in Switzerland and I urgently need to get in touch with photographer Chan Yoke Meng, who takes beautiful photographs of birds near Singapore. Would you please mail me the email address of this photographer!
Thanks,
Martin