Author: OkamotoKeitaSin

On 1 November 2022, excitement spread through our local birding community when Art Toh shared his sighting from Sungei Buloh Wetland Reserve of a white ibis donning a black head. Birders headed down to get a glimpse of the bird which thankfully stayed for several days, allowing many to observe it. The Singapore Bird Records Committee took some time to evaluate the record and we assessed that this individual is likely to be Singapore’s first documented individual of a wild Black-headed Ibis Threskiornis aethiopicus.

How was the bird identified?

There are several species similar to the Black-headed Ibis such as the African Sacred Ibis T. aethiopicus, Australian Ibis T. molucca and Malagasy Sacred Ibis T. bernieri. These four species were previously all thought to be one species, then called the Sacred Ibis, until works including the evaluation of their plumage differences established that they were distinct from one another (Lowe & Richards, 1991).

The range restricted Malagasy Sacred Ibis can be differentiated from the other three by its white iris among other features. However, the Australian Ibis and African Sacred Ibis look quite similar to the Black-headed Ibis. Differences between them include their bill size, which can sometimes be difficult to assess in the field. How should we identify the Sungei Buloh bird then?

The magic is in the small details: one of the key features to look out for is the primary pattern – the black markings are restricted to tips of the three outermost primaries in Black-headed Ibis, unlike that in the African and Australian Ibis that are more extensive. Additionally, the tertial feathers in Black-headed Ibis is grey, as opposed to black in African and Australian Ibis.

Here are some images showing these features on the African Sacred Ibis (extensive primary markings: example 1, example 2 and example 3; black tertials: example 1 and example 2) and Australian Ibis (extensive primary markings example 1 and example 2; black tertials: example 1 and example 2).

Comparing the “Sungei Buloh Ibis” with photographs of known Black-headed Ibises shows that the features fit this species perfectly instead.

Is the Sungei Buloh Black-headed Ibis a wild bird or an escapee?

Now that we’ve identified the bird, then comes the question of its provenance. Interestingly, the Sungei Buloh bird is actually not the first Black-headed Ibis seen in Singapore! This species used to be sighted locally back in the ~80s but were then thought to be escapees from the Jurong Bird Park (Wang & Hails, 2007). Today, the Mandai Wildlife Reserve makes an effort to ring all birds, and there are no free-flying Black-headed Ibises as far as we understand. Sungei Buloh’s Black-headed Ibis had no rings on its leg, making it unlikely that it originated from the Jurong Bird Park.

Where could the bird have come from, then? The Black-headed Ibis has a patchy range and inhabits wetlands from South Asia all the way to Indonesia. In Thailand, they are resident in the southern parts and disperse in the winter months (Treesucon & Limparungpatthanakij). Slightly closer in Peninsula Malaysia, there might have been wild breeding populations in the past, but if any were extirpated nearly a century ago (Wells, 1999; Puan et al., 2020). There are now only very occasional sightings along the landmass (such as this record). Meanwhile in Sumatra and Java, the populations used to be very robust but have declined dramatically in the past few decades (Iqbal & Hasudungan, 2012). The birds there are, however, thankfully still present (Muhammad Iqbal, personal communications).

It is still difficult for us to establish whether the bird came from the north or from the Indonesian population. Several waterbirds like the Pied Stilt and Javan Plover have made their way from the Indonesian Archipelago. At the same time, there was, interestingly, yet another sighting of a Black-headed Ibis near Malacca just 3.5 weeks after the Sungei Buloh bird. This sighting bolsters our decision that the Sungei Buloh bird was likely from a wild origin, and might provide hints to where it could have arrived from.

Wherever the bird flew over from, we hope that it’ll successfully find some friends and return to a colony to breed safely. And who knows, we might get more of them visiting us in the future!

Acknowledgements

We would like to express our gratitude to Art for sharing the sighting very promptly, and also thank Adrian, Bao Shen and Cheng Teng for photo contributions.

References

Lowe, K. W., & Richards, G. C. (1991). Morphological Variation in the Sacred Ibis Threskironis aethiopicus Superspecies Complex. Emu, 91(1), 41-45.

Puan, C. L., Davison, G., & Lim, K. C. (2020). Birds of Malaysia: Covering Peninsular Malaysia, Malaysian Borneo and Singapore. Lynx Edicions, Barcelona.

Treesucon, U., & Limparungpatthanakij, W. (2018). Birds of Thailand. Lynx Edicions, Barcelona.

Wang, L. K., & Hails, C. J. (2007). An annotated checklist of the birds of Singapore. Raffles Bulletin of Zoology Supplement, 15, 1–179. Link

By Laura Berman

A recent publication in the Journal of Ornithology has some interesting new data on the breeding seasons of Singapore’s birds, and if you are an avid contributor to eBird, your observations might be a part of it.

Singapore has an incredibly dedicated birding community, and many birders share their observations of nests, baby birds, and fledglings. All those observations were taken together with half a decade of mist-netting data collected by the Avian Evolution Lab at NUS and the National Parks Board to outline the breeding season in Singapore.

If you look hard enough you can find birds building nests in Singapore just about any month of the year, but you’re much more likely to succeed if you go looking in March – that’s when most insectivores like Malaysian Pied Fantails and frugivores like Coppersmith Barbets and Black-naped Orioles are constructing nests. Granivores like Baya Weavers nest a bit later in the year, the best chance to catch them constructing their charismatic hanging nests is in June. You’re most likely to come across active nests with unhatched eggs if you go looking in April or May. June to July is the best time to see parents feeding their fledglings, and very young birds still chasing their parents begging for food. By the time August comes around the breeding season is over, but if your field ID is particularly good you might be able to recognise juvenile birds still in their first set of flight feathers.

It’s always exciting to see nests and baby birds but remember not to get too close. Its stressful enough being a parent.

Another example of a very widespread frugivorous species, the Black-naped Oriole. They are very common in Singapore, but finding their nest takes a bit of effort! Photo credit: Goh Cheng Teng

Granivorous species like the Baya Weaver , known for their intricate nests, tend to breed later in the year. Photo credit: Keita Sin, taken in Malaysia

Insectivorous birds like the Malaysian Pied Fantail that likes to nest near waterbodies often nest around March. Photo credit: Keita Sin

Frugivorous birds like the Coppersmith Barbet tend to nest around March too. Photo credit: Goh Cheng Teng

References

Berman, L., Li, D., Yang, S., Kennewell, M., Rheindt, F. (2022) Breeding season linked to sunshine hours in a marginally seasonal equatorial climate. Journal of Ornithology. https://doi.org/10.1007/s10336-022-02009-9. Link

And so it’s been a year since we launched the Singapore Bird Database. Time really flies. This time a year ago, the Fairy Pitta at Hindhede Nature Park that we queued for was already gone, and many of us were busy chasing Singapore’s first proper documentation of the Grey-streaked Flycatcher.

Nostalgia feels good, but for now, let me share some updates on our database.

Our database was launched to provide a platform where anybody can easily find relevant information regarding rare bird species in Singapore. Since then, we’ve received over 25,000 views on our database website, and we’re glad that many of you have found our work useful. For those who are keen to find out how our platform came to life, you can check out our blog post or detailed write-up.

Information available in our database has almost doubled over the past year, and it now contains over 2000 records from more than 180 species. While many were compiled from social media archives, publications, and past eBird records, nearly 300 were submitted by none other than all of you – birders in the field – to which we would like to express our huge thanks to. 300 submissions, only for rare birds! All of these submitted records were evaluated by our Singapore Bird Records Committee team, whose latest works are constantly updated in our Recent RC Decisions page. We’ve been very busy – a happy problem because it means that our community has been finding a lot of good birds! 

Moving on to how the Singapore Bird Records Committee has evolved since then, first, we have developed an operational guideline that can be viewed in a Q&A format here. Second, we are renaming the term “Rarity” to “Review Species” in our checklist. It might sound like a matter of semantics, so allow us to explain. Our Records Committee makes a concerted effort to properly evaluate and document records of birds that one might not necessarily think is that rare. Say, Pied Harrier. This is an annually recorded raptor, but in numbers small enough that warrants celebration. This season, we seem to be witnessing a strange spike in their numbers for reasons unknown, and patterns like this will be missed if not for proper efforts. Another good example is the form of Barn Swallows with rufous underparts. we occasionally observe At present, we don’t even know which subspecies actually arrive here, but what we do know is that they are rare in Singapore, and that records keeping would be essential for future generations to have a point of reference when the ornithological community one day have a better understanding of these birds. In principle our workflow stays the same, and so we’d greatly appreciate it if you could submit your encounters. This terminology change will be reflected in our Species Pages as well in due time.

Our database has changed in more ways than one, and here is a comparison of how it looked 1 year ago versus today. Besides new features and useful tools, the layout now emphasises images and is more colourful and easy to use. An archived version of our website from Nov 2021 is available here.

Last, our database works have extended beyond collating records, and we’ve designed useful tools for everybody’s birding activity. Our Monthly Roundups provide accurate information on interesting species documented each month, and our bar charts can help you plan your birding itinerary to best target the species that you really want to see. If you’re hungry to find the next Mega in Singapore, you can also refer to our On This Day page to find gems from the past.

Moving forward, we aim to revisit all of our Species Pages for further improvements, and also plan to expand our database and website to include more species. If you have ideas for collaboration or are keen to help out with our work, don’t feel shy to get in touch with us!

I’d wrap up this update with the most important bit, the acknowledgements.

See all those Monthly Roundups and Bar Charts? They didn’t just fall out of the sky (though the birds did) – they were possible thanks to the tech-wizardry of Raghav, to whom we extend our utmost gratitude.

See those crazy numbers of historical records newly compiled in our database? They were collated and scrutinised by our amazing Singapore Bird Project teammates Clarice, Geraldine, Jenwei, Jing Ying, Hong Yao, Hui Zhen, Raghav, and Zachary. Massive, massive thank you for the hard work – checking through all those records is really not easy.

And lastly, to all the birders for your all-rounded support and for sharing and submitting your sightings – the Singapore Bird Records Committee thanks all of you.

See you all in the field and happy birding!

PS, IN CASE YOU MISSED IT:

We were invited by the Lee Kong Chian Natural History Museum to give a talk about our database in March 2022. Check it out too if you couldn’t join us!

Regardless of where you come from, you’re missing out on the Singaporean experience if have you never queued long long for food before. And it seems that our locally found parrots know that too! Here are some intriguing observations on the feeding behaviour of three parrot species – Tanimbar Corella, Coconut Lorikeet and Blue-crowned Hanging Parrot.

By Muhammad Nasry

Earlier this year, an alert that a stretch of mango trees around the Alexandra Village area was fruiting and attracting Coconut Lorikeet Trichoglossus haematodus began circulating online, featuring eye-level shots of this colourful parrot happily munching away at the fruit. Naturally, this attracted a whole horde of birders, myself included. Having lived near the area since birth but blithely unaware of the existence of these mango trees, I was a little embarrassed for not realising sooner, but excited by the discovery of a new birding spot just minutes from my doorstep.

And so I visited. Again. And again. And again.

Over the course of several visits I began to notice an odd pattern in terms of the foraging behaviour of some of the birds there. Consistently, this feeding pattern repeated itself over and over.

The first to arrive was usually the Tanimbar Corellas Cacatua goffiniana. These parrots seemed to prefer feeding on the outermost bits of the mango fruit, only occasionally reaching deeper into the mango for more of the pulp.

Second on the scene was typically the star attraction: the Coconut Lorikeets. They would pick up where the corellas had left off, peeling off what remained of the fruit skin. They would then proceed to rip apart the rest of the fruit (as parrots do) while eating, with the bits of fruit either being scattered on the surrounding foliage or dropping straight to the ground.

The lorikeets were often seen foraging in pairs, with the occasional dispute breaking out between pairs over mangoes. There were up to three pairs seen at the same area at any one time. In one instance, one of the pair was feeding while the other stood guard, screaming its head off to ward off any would-be usurpers of the coveted mangoes. 

Only after the lorikeets left would the Blue-crowned Hanging Parrots Loriculus galgulus move in on the fruits. A male and female were both seen feeding here, but never at the same time.

This feeding order was generally consistent – each parrot species usually came to feed only after the previous one had left. Competition due to size differences may explain this pecking order (pardon the pun), given that the corellas are the largest, and hanging parrots the smallest. The issue with this theory is that there were plenty of mangoes to go around, many of them a similar shade of green as the ones being eaten (which presumably indicates they were equally edible) and therefore competition was not necessary. However, the hanging parrots seemed to pass up these seemingly fine mangoes in favour of those that had already been opened by the two introduced parrot species. Perhaps letting the bigger parrots do the hard work of opening up the unripe mangoes may be more convenient for them – they may have to use a lot more effort with their comparatively smaller beaks to open up the mangoes on their own. 

The messy eating habits of the parrots did not go unnoticed by other animals; there were intermittent visits to the mangoes (or to the bits of mango strewn around on the branches) by other common urban species, which included:

• Olive-backed Sunbird Cinnyris jugularis
• Brown-throated Sunbird Anthreptes malacensis
• Yellow-vented Bulbul Pycnonotus goiavier
• Black-naped Oriole Oriolus chinensis
• Plantain Squirrel Callosciurus notatus
• Chocolate Pansy Junonia iphita

The following species were also seen in the vicinity, but had not been observed feeding on the mango fruits, be it directly or indirectly.

• Scarlet-backed Flowerpecker Dicaeum cruentatum
• Javan Myna Acridotheres javanicus
• Common Myna Acridotheres tristis
• Common Hill Myna Gracula religiosa
• Painted Jezebel Delias hyperete
• Grass Yellow Eurema sp.

It is interesting that the feeding behaviour of the introduced parrot species benefited other wildlife species (birds or otherwise). It may be possible that many more species may benefit from such interactions in other habitat types as well. Ground-dwelling fruit-eaters like the Asian Emerald Dove or Lesser Mousedeer may benefit from the bits of fruit scattered around the forest floor thanks to the parrots’ poor table manners. Of course, these interactions took place in a relatively urban habitat next to a busy road – generalisations to less developed habitats would not be wise without further study.

References

Nasry, M. (2022) Biodiversity Record: Observations of some urban birds feeding on mango fruit. Nature in Singapore, 15, e2022095. URL

In the winter of 2014/2015, Singapore experienced a flood of Cinereous Bulbuls and Streaked Bulbuls. An influx of some sort, it seemed. These typically uncommon bulbuls appeared all over the country, with observations including a flock of nearly 200 Cinereous Bulbuls at Pulau Ubin. During that period, many other surprises showed up: two separate Green Broadbills, Yellow-eared Spiderhunter, Yellow-vented Flowerpecker, and Thick-billed Flowerpecker to name a few. Most of them were species that are rare visitors to Singapore (the Green Broadbill especially, being the first two records since their extirpation in 1941) though common in the lowlands of the region, such as the forest patches of Johor just an hour’s drive by car, or the islands in Riau a boat ride away.

The next few seasons were lacklustre with regards to these groups of birds despite the rapid spike of birdwatchers in the country. Both bulbuls only appeared sporadically and in much smaller numbers, and regional lowland rarities (?) continued to be found but at a rather slow pace. In the 2018/2019 season, a handful of Cinereous Bulbuls appeared and were once again accompanied by some Streaked Bulbuls. Their numbers dwindled through summer, and the 2019/2020 season was a similar case.

Then in the winter of 2021/2022, Singapore observed a familiar scene of mass Cinereous Bulbul arrivals. Streaked Bulbuls followed suit, and multiple rare regional species showed up in Singapore as if their calendars were synchronised: two Black-thighed Falconets (the first since 1990), Green Broadbill (first since 2014), Scarlet Minivet (first since 2001), Yellow-vented Flowerpecker, and Scarlet-breasted Flowerpecker (first confirmed record for Singapore).

The peaks and troughs of Cinereous Bulbul (blue), Streaked Bulbul (red), and locally significant Sundaic visitors (green) sightings in Singapore. Sundaic visitors are considered “locally significant” for the purposes of this illustration if they have less than 10 records in the last 10 years. The table below this article lists all the records of these locally significant Sundaic species from this illustration. Note that a single record is defined as an individual or group of individuals present at one site for a period of time. So although there were hundreds of Cinereous Bulbuls across Singapore in both the 2014 and 2021 peaks, the number of records is far smaller.

These sightings are more than just déjà vu; they possibly hint towards some form of ecological force driving the birds southwards that we are yet to understand (assuming they primarily came from Johor). Indeed, unorthodox movements of birds – be it at a large or small scale – are periodically observed. In 2019/2020 we had a spate of Indochinese birds arriving in Singapore, and just last season we were kept busy with species that typically winter in the Indian and Middle-eastern region (remember the Cinereous Vulture, Amur Falcon, Black Redstart and Spotted Flycatcher?).

Very recently in May we also observed a rush of regional species to Pulau Ubin, with Black-and-red Broadbill, Black-and-white Bulbul, Lesser Green Leafbird and Scarlet-breasted Flowerpecker showing up. Strangely, Cinereous and Streaked Bulbuls were absent from the rave, and the birds were concentrated to Chek Jawa but not elsewhere in Singapore – perhaps the cause for the latest event differs from the seemingly periodic influxes we get. Could it have been due to land-use change in the region? Was there a particular tree in Chek Jawa blocked from our views that provided a very attractive food source? We don’t know, and these are at best educated guesses. However, with proper housekeeping of local bird records, we might eventually be able to search for the answers to these questions. For example, reliable long-term data coupled with environmental modelling showed that the Indian Ocean Dipole event (a phenomena where the Indian Ocean’s western section becomes unusually warmer than the eastern section) led to an influx of Red-necked Phalaropes to the region around Kenya in 2019/2020). Our continued and collective efforts to document Singapore’s birds will surely play a key role in advancing our knowledge in the years to come.

As for now, while our understanding is limited, the patterns suggest one thing: get your gears prepared and be on high alert when Cinereous and Streaked Bulbuls start showing up. These two species seem to serve as messengers for the rendezvous of regional birds rare in Singapore. There are many species on our checklist to look out for: Silver-rumped Spinetail, Whiskered Treeswift, White-bellied Woodpecker, Great Slaty Woodpecker, Malayan Black Magpie. Or perhaps other megas not even on the Singapore checklist – I’d like to place an order for a Brown-backed Flowerpecker please!

We recently contributed an article to BirdingASIA to highlight these avifaunal records from our community during the 2020-2021 season and the possible implications behind them. As the national borders start opening up, many of you who picked up this obsession hobby of birding recently must be craving to, or might have already started to explore beyond Singapore. If you’re keen to read more about birding news from the Asian region, do consider subscribing to the Oriental Bird Club! You’ll receive two copies of BirdingASIA with more exciting articles from the region, as well as one copy of the Journal of Asian Ornithology where latest research on regional avifauna are highlighted. (Just for the record, the Singapore Birds Project is not affiliated in any way to the Oriental Bird Club. We do not get any commission or benefits from promoting them.).

Happy birding, and please do share your sightings if you happen to come across any of these rarities and submit your records to the Singapore Bird Database for proper archival!

Table of records of locally significant Sundaic species, as displayed in the chart above (2014-2021)

References

Nussbaumer, R., Gravey, M., Nussbaumer, A., & Jackson, C. (2021). Investigating the influence of the extreme Indian Ocean Dipole on the 2020 influx of Red-necked Phalaropes Phalaropus lobatus in Kenya. Ostrich, 92(4), 307-315.

Sin, Y.C.K., Narayanswamy, R., Ng, D., Chia, S., Ng, E., & Kennewell, M. (2022). Beyond the pandemic: gems from Singapore in 2020-2021. BirdingASIA, 37, 101-108.

Streaked Bulbul at Dairy Farm Nature Park. Photo Credit: Francis Yap

Cinereous Bulbul at Kent Ridge Park. Photo Credit: Francis Yap

Juvenile Green Broadbill at East Coast Park. Photo Credit: Francis Yap

Yellow-eared Spiderhunter at Dillenia Hut. Photo Credit: Francis Yap

Thick-billed Flowerpecker at Dairy Farm Nature Park. Photo credit: Francis Yap

Yellow-vented Flowerpecker from Panti Bird Sanctuary. Photo credit: Con Foley

Black-thighed Falconet at National Equestrian Centre. Photo credit: Francis Yap