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RAP101: How to Identify Common Raptors

The peak of Singapore’s raptor migration will soon be upon us. From October to December, large numbers of migratory raptors will pass through Singapore, as they move from their breeding grounds in temperate northeast Asia to tropical southeast Asia (Bildstein, 2006). This constitutes autumn migration, where birds migrate southwards to avoid frigid winters in their home grounds. Around March to May, the birds will head back north to breed, but fewer species seem to pass through Singapore and in smaller numbers. Different species of raptors have been observed to peak in their passage through Singapore in different months.

During this period, you’ll find birders heading to popular raptor watching spots such as Henderson Waves, Telok Blangah Hill Park and Tuas to try their luck at snagging rarer ticks, or to enjoy viewing the large number of raptors migrating overhead. At the same time, you’ll find posts popping up on local Facebook pages requesting for raptor identification. While raptor plates in field guides are handy for identification, good guides can be costly and those short on cash or new to the hobby may not be keen on making such purchases yet. Even so, while guides have detailed illustrations of the raptors in full colour with all identification features clearly indicated, migrating raptors often thermal high in the sky and our grainy, backlit pictures may look like this:

Large flock of migratory raptors at Henderson Waves, Singapore. Photo Credit: Sandra Chia

So how do we tell what’s what?

Equipped with my trusty but outdated Nikon 300mm F4 (no teleconverter!), my photos of migrating raptors may be the worst of the lot. Thankfully, you do not need amazing photos to identify the dots passing overhead. This article will feature five common raptors: Changeable Hawk Eagle (Nisaetus cirrhatus), Crested Honey Buzzard (Pernis ptilorhynchus), Chinese Sparrowhawk (Accipiter soloensis), Japanese Sparrowhawk (Accipiter gularis) and Black Baza (Aviceda leuphotes), and we’ll go through some general pointers on how to differentiate what’s what.

Changeable Hawk Eagle (Nisaetus cirrhatus)

Identifying features marked out on a Changeable Hawk Eagle silhouette. Taken at Henderson Waves, Singapore. Photo Credit: Sandra Chia

The Changeable Hawk Eagle is a medium sized raptor with seven ‘fingers’. Some individuals undergoing moult may have less than seven ‘fingers’, but can still be differentiated by its round wings, which result in a silhouette with pronounced ‘armpits’. This species can come in a dark or pale morph. This is an uncommon resident species that may often be seen while observing migratory raptors.

Crested Honey Buzzard (Pernis ptilorhynchus)

Identifying features marked out on a Crested Honey Buzzard silhouette. Taken at Henderson Waves, Singapore. Photo Credit: Sandra Chia

The Crested Honey Buzzard is another medium sized raptor with six ‘fingers’. The migratory subspecies, Pernis ptilorhynchus orientalis, is commonly referred to as Oriental Honey Buzzard. If moulting, individuals may also have fewer than six ‘fingers’. It can be differentiated from other medium sized raptors by its relatively small head and less rounded wings. The Crested Honey Buzzard also comes in various morphs such as light, dark, and an array of intermediate morphs (DeCandido et al., 2015). If you would like to take a deep dive into Crested Honey Buzzard identification, you can check out DeCandido et al. (2015).

Chinese Sparrowhawk (Accipiter soloensis)

Identifying features marked out on a Chinese Sparrowhawk silhouette. Taken at Henderson Waves, Singapore. Photo Credit: Sandra Chia

The Chinese Sparrowhawk is an Accipiter, a globally distributed genus typically known as hawks.  Accipiters are generally smaller than the two raptors discussed above, resulting in a very different general impression of their size and shape. This species has four ‘fingers’, tipped black. More information on how to identify males, females and juveniles of the species can be found on our species page here.

Japanese Sparrowhawk (Accipiter gularis)

Identifying features marked out on a Japanese Sparrowhawk silhouette. Taken at Henderson Waves, Singapore. Photo Credit: Sandra Chia

The Japanese Sparrowhawk is of similar size to the Chinese Sparrowhawk but can be told apart as it has five ‘fingers’ instead of four. More information on identification of males, females and juveniles can also be found on the species page, here. More information on telling apart Accipiter species can be found in DeCandido et al. (2014).

Black Baza (Aviceda leuphotes)

Identifying features marked out on a Black Baza silhouette. Taken at Henderson Waves, Singapore. Photo Credit: Sandra Chia

The Black Baza is of similar size to the sparrowhawks discussed above but differs by its wing shape, which is more rounded than that of the sparrowhawks, resembling paddles. It is also distinctly coloured, with a prominent band of white across the upper breast and thinner black, white, and chestnut stripes across the lower breast and belly. This species is mostly seen from late November onwards (eBird, n.d.).

We hope this article has served as a useful crash course on identification of common raptors we might encounter while raptoring in the coming months. Leave a comment below if you’d like us to cover other species!

Happy raptoring and hope to see everyone’s lists on eBird!

Acknowledgements

Thanks to Jin Rong and the team (Dillen, Francis, Keita, Movin and Raghav) for their comments on the article and to the experienced birders who taught me how to identify raptors over the years.

References

Bildstein, K. L. (2006). Migrating raptors of the world: their ecology & conservation. Cornell University Press.

DeCandido R., Nualsri C., Siponen, M., Sutasha, K., Pierce A., Murray, J. & Round, P. D. (2014). Flight identification and plumage descriptions of six Accipiter species on southbound migration at Khao Dinsor, Chumpon province, Thailand. BirdingASIA, 21(2014), 52-62. Link: https://www.researchgate.net/publication/303712756_Flight_identification_and_plumage_descriptions_of_six_Accipiter_species_on_southbound_migration_at_Khao_Dinsor_Chumphon_province_Thailand

DeCandido, R., Siponen, M., Smit, H., Pierce, A. & Allen, D. (2015). Flight identification and migration pattern of the Oriental Honey Buzzard Pernis ptilorhynchus orientalis in southern Thailand, 2007-2014. BirdingASIA, 23(2015), 27-33. Link: https://www.theflywayfoundation.or.th/download/Oriental%20Honey%20Buzzard%20in%20southern%20Thailand%202007%E2%80%932014.pdf

eBird. (n.d.). Black Baza. https://ebird.org/species/blabaz1/SG

Singapore Avifauna records on eBird

Five of the 27,000+ records uploaded to eBird from the old Singapore Avifauna newsletters. Photos taken in Singapore and elsewhere (credit: Raghav Narayanswamy and Keita Sin).

For much of my first few years of birding in Singapore, I wondered how the data from earlier eras in local ornithology could be made available for more to benefit; if early dates and late dates, major hotspots, past trends in the local avifauna, among other useful information, could be compiled in an accessible format for the community at large. After all, this small country has always been blessed with a higher-than-average observer coverage relative to its surrounding regions. The data could fill major gaps in understanding Asian avifauna, and be greatly beneficial to interested local birdwatchers as well.

So when I first saw that the Nature Society (Singapore) (NSS) had made its old editions of Singapore Avifauna from 1987 through 2010 available on its website, it was immediately clear that this could be a great resource for the birding community in Singapore if it could be consolidated into a more readily-accessible format. To really know how many times a species has been recorded locally, or which months it appears most frequently, manually scrolling through hundreds of reports for that species would not be practical. Rather, the data would need to be in a spreadsheet, and easily searchable, for the information to be most useful.

Recently, as Keita discussed last week, eBird has established itself as the most widely-used citizen science database for avian records. Many studies have referenced data stored in eBird to examine trends and achieve important conservation outcomes. It also reached a major milestone — 1 billion bird observations — in May this year, reinforcing its position as a powerful tool for conservationists and casual birders alike to share observations and further broaden our collective knowledge. It was clear to me that putting these important records from SINAV on eBird was the best way to make them as impactful as they can possibly be.

In collaboration with Singapore’s eBird reviewer Martin Kennewell, after obtaining permission from NSS to consolidate and upload the records, I set to work on designing a program to extract species names, observation counts, dates, and locations, as well as observer names for proper credit, for all the volumes of Singapore Avifauna available on the NSS website. Dividing this process into two steps: conversion of the PDFs (stored as images) into text, followed by extracting the important details from the text, I was able to upload over 27,000 individual observations, around 23,000 from Singapore and 4,000 from Malaysia and Indonesia.

The records uploaded now make up around 75% of all eBird records until 1990, and over 25% of all records until 2010 (the last year that Singapore Avifauna was published).

I can’t say that this journey was always smooth; one of the biggest challenges I faced was resolving old locations, with old place names, to current landmarks or points on the map which could be uploaded to eBird. With Martin’s expertise and support, I was able to resolve most of these, and sent a further few to NSS for their review. Additionally, some older editions of SINAV were missing; indeed, this was an era with limited technological access and keeping track of documents was admittedly more challenging than it has become today. Older records also suffered from a lack of specific counts; especially as birds that have now become rare once numbered in the dozens or even hundreds, observers sometimes may not have made the effort to accurately count these species.

See, for example, the entry for Sanderling in the report for February 1987.

This species is now barely an annual visitor; in the 80s, 90s, and even the early 21st century, counts in the double digits were regular. It’s hard to believe this count of 100 Sanderlings along with exceptional counts of other shorebirds, was just over 15 years ago.

A mixed flock of shorebirds in Thailand from 2019. Such scenes are now nothing more than a distant dream in Singapore today.
A mixed flock of shorebirds in Thailand from 2019. Such scenes are now nothing more than a distant dream in Singapore today.

Sometimes the work was tiring and it became difficult to continue, but I always knew the reward of making all these sightings accessible was worth the effort. In the end, after probably 100 hours of work, I uploaded the data to the NSS Records eBird account.

An example

The excerpts below are from Volume 19 (Jan-Mar) of Singapore Avifauna, published in 2005 (link). I’ve used this example to highlight how the process of digitizing reports into individual records works. For January, February, and March of 2005, Blue-crowned Hanging-Parrots were recorded a total of 12 times. Since the report is split into each of the months, this species appears three times.

These three entries are then converted into text with optical character recognition and combined into one overall entry for the period covered by the report, in this case January to March:

BLUE-CROWNED HANGING-PARROT Loriculus galgulus
1 over Dairy Farm Road, 17/1 (LKS) and 18/1 (LKS) and 4 at Malcolm Park, 30/1 (NK/LKS/FR/IR/JR). At Botanic Gardens, 7 were counted on 4/2 (LKS) and 5 on 28/2 (AF/LKS). Also 3 over Nee Soon, 8/2 (LKS), 1 at MacRitchie Reservoir, 16/2 (LKS) and 28/2 (AF/LKS), and 1 over Dairy Farm Road, 24/2 (LKS). 1 heard at the foot of Bukit Timah, 12/3 (LKS), 1 flying over Dairy Farm Road, 22/3 (LKS) and 3 at Sime Road, 27/3 (LKS).

The individual records are then separated by looking for “sets” comprising the four important pieces of information for each record: count, date, location, and observer names. Of these, the most challenging to parse out is the location. In this case, there’s no extraneous information that we need to ignore, so it seems relatively straightforward to just use the leftover text as the location. But sometimes, sightings are associated with lengthy descriptions and the location needs to be extracted from that description – so I had to use natural language processing to pick out the location.

For the example above, the following 12 sightings would then be uploaded to eBird. This checklist shows how the first record (17 Jan) would appear in eBird’s outputs.

This project is mostly complete, and with it, thousands of bird observations recording hundreds of species have now been placed somewhere they can be accessed by researchers and amateurs alike. As more people come forward to contribute their sightings and share their knowledge, we can make more meaningful progress in conserving our valuable local wildlife.

Acknowledgements

This piece was written with the help of comments and advice from the Singapore Birds Project team (Dillen, Francis, Keita, Movin, and Sandra). My project drew on over a hundred reports made available by NSS on its website; their permission for me to take on this project also made this project possible. I also appreciate Martin’s contribution to many aspects of my project, including location-matching and manual approval/rejection of the uploaded records.

References

Sullivan, B. L., Aycrigg, J. L., Barry, J. H., Bonney, R. E., Bruns, N., Cooper, C. B., … Kelling, S. (2014). The eBird enterprise: An integrated approach to development and application of citizen science. Biological Conservation, 169, 31–40. doi:10.1016/j.biocon.2013.11.003

Sullivan, B. L., Wood, C. L., Iliff, M. J., Bonney, R. E., Fink, D., & Kelling, S. (2009). eBird: A citizen-based bird observation network in the biological sciences. Biological Conservation, 142(10), 2282–2292. https://doi.org/10.1016/j.biocon.2009.05.006

Why you should start using eBird!

Imagine a world where you could predict the arrival of your favourite migratory bird, get immediate identification help for an unfamiliar bird, and contribute to science and conservation just by being out in the field. I have some fantastic news for you…that’s the world we live in now!

BirdCast is a forecast map that utilises weather forecast maps to model bird migration. Scientists from the Cornell Lab of Ornithology are able to track data on how birds travel, allowing myriads of research ranging from the effects of climate change, to single events such as the influences of hurricanes on bird movements to be projected. One of the key components that makes BirdCast functional is data from eBird. The most rudimentary form of data – actual bird encounters from the birdwatchers in the field – are combined with highly intricate weather surveillance infrastructure, to make fairly accurate predictions of bird migration. A well-known example of how eBird data has transformed the birding experience of beginners is the Merlin platform which uses Artificial Intelligence (AI) to identify birds. Users simply need to upload a photograph or sound recording of the bird and the AI will suggest several potential candidates. This complex AI did not magically appear, though – it was made possible through feeding tons of photographs and sound recordings to the computing system, once again with the help of eBird data. These platforms allow birding to be much more targeted, focused, and friendly, both for beginners and the most hardcore of birdwatchers. Sounds great, doesn’t it? Now here’s the catch: at present, BirdCast is only available in the United States. The platform was first launched in 2018, and research is still concentrated in the area where eBird data is most abundant. On the other hand, although Merlin started out being only available in United States initially, there is now a package for Singapore, though it still struggles with similar looking birds such as Phylloscopus warblers. With enough contribution from the regional birding community, other platforms such as BirdCast will hopefully be made available to us as well. A massive way you could contribute to improving the precision of these tools is by contributing to eBird.

eBird is a citizen-science platform that was first launched over 10 years ago (Sullivan et al., 2009) and anybody is able to create an account for free. Through the platform, bird sighting information, along with their photographs and sound recordings, can be uploaded. A highly user-friendly mobile phone application is available and all you need to do when you are out birding is to start a list, select a location, and just tap a button that corresponds to a species you encounter in the field. Detailed information such as sex, behaviour, and other observations can be optionally added. A web platform is also available where you can later upload the photographs and sound recordings you took.

A simple example of how the eBird mobile app works. All you need to do is tap some simple buttons!

In your eBird account, not only will you be able to check your daily sightings, but you can also track your birding statistics by generating monthly or yearly summaries. Furthermore, there is a particular function that you would definitely love as a birder – the needs and rarities alert. These alerts will send you emails when other eBirders find a bird that you need (i.e. not recorded in your eBird account) or are locally significant. In these alerts, you can even set multiple filters to suit your needs: for example, if you have seen a Fairy Pitta Pitta nympha elsewhere before, you might not necessarily find the need to see one in Singapore so you can filter it out from your personalised eBird alert list. On the other hand, if you are doing a big year, you might want to search for relatively common birds such as the Dark-sided Flycatcher Muscicapa sibirica the moment one is locally seen.

The eBird settings page where you can subscribe to your preferred alerts.

Some might have reservations regarding immediate sharing of sightings – certain sites such as housing estates might be sensitive, or some birds might be nesting when you find them. In such cases, you can also upload your data post-hoc through an easily formattable excel sheet once you are comfortable with making the data public. Likewise, if you prefer to be private, there are options to upload your sightings anonymously or hide your lists (you will still need an account, but your name/list will not be displayed publicly). Additionally, concerns about the dangers of publicising locations for species such as the Critically Endangered Straw-headed Bulbul Pycnonotus zeylanicus due to the presence of poaching activities can be eased: there is a “sensitive species” filter set by regional reviewers that hides specific sites.

You might also be thinking: “I’m not a bird expert, what if I make mistakes?” – don’t worry! eBird data is constantly curated by regional reviewers that will ensure that the information is as accurate as possible. When potential mistakes are noticed, you will be notified via email. Moreover, when you are submitting data via the eBird application, the platform will flag out potential rarities that will allow you to enter specifics of your sightings. These filters are constantly reviewed and updated by the local expert (the eBird reviewer) to ensures that the flags do not appear irrelevantly. Uploading photographs and sound recordings will also be helpful, as not only is the reviewer able to check the data, any eBird user is able to report incorrect identifications. Similarly, you might be apprehensive about the perceived “quality” of the data you are contributing: “what if all the birds are common and boring? Won’t such data be useless?” – the answer is no! Data of all species – however common they are – are very valuable when conducting scientific research and consequently conservation planning. For example, if there is a site with 100 checklists per month, mostly filled with common species such as Yellow-vented Bulbuls P. goiavier and Brown-throated Sunbirds Anthreptes malacensis, we can be quite sure that conclusions we make based on information from the area is fairly accurate. Conversely, if checklists at such sites are not created because the species assemblage is “mundane”, the area will end up becoming a big question mark – could there be an undetected population of Greater Green Leafbirds Chloropsis sonnerati hiding there? Could there be huge numbers of introduced waxbills colonising the place? Furthermore, species that we think as “common” today might not continue to be in the future and vice versa. For example, the Red-wattled Lapwing Vanellus indicus, ubiquitous in most grassfields in Singapore today, was actually a locally rare bird just 20 years ago (Lok & Subaraj, 2009; Wang & Hails, 2007)! A steady stream of checklist will tremendously improve the data quality.

In Singapore, many of us share our sightings through social media sites such as Facebook groups or Telegram/WhatsApp groups; the eBird patronship fraction in our community is still relatively low. However, the number of eBirders has been rapidly picking up since ~2015, and the impacts of this increased usership have been tremendous. For example, Singapore’s first Siberian House Martin Delichon lagopodum and Hair-crested Drongo Dicrurus hottentottus were only discovered months after the birds were gone by A/P Frank Rheindt from the NUS Avian lab when he was scrolling through eBird photographs of the similar looking Asian House Martin Delichon dasypus and Crow-billed Drongo Dicrurus annectans. Similarly, counts from eBird were very useful in quantifying the sheer oddity of the 2019/2020 migration season we enjoyed two years back, especially for species including the Red-rumped Swallow Cecropis daurica and Whiskered Tern Chlidonias hybrida (Sin, Ng, & Kennewell, 2020). Data are not just restricted to members from the Cornell lab, but can be downloaded by any citizen-scientist or researcher upon request. These database, unlike information that are stored in notebooks, scattered pdfs, or people’s memory, are easily searchable and accessible. Both scientific and conservation action can be achieved with fine scale information, to which you can be a part of.

eBird data confirmed that the Red-rumped Swallow occurred in very high numbers during the 2019/2020 migratory season. This photograph was taken in Japan. Photo credit: Keita Sin

With all that said, I hope this article has broadened your perspective on how you can be an important contributor to bird science as well as improve the birding experience in our local scene!

Acknowledgements

A massive, massive thanks to Martin Kennewell (Singapore’s eBird reviewer) for the constant efforts in promoting the platform locally as well as taking on the tremendous task of moderating the data throughout the past few years. I also thank my team members from the Singapore Bird Project (Dillen, Francis, Movin, Raghav, Sandra), as well as Tan Hui Zhen and Geraldine Lee for comments on this article. Last but not least, a huge thanks to all eBird users out there, and if you are not one, I hope this article has convinced you to be one!

Disclaimer: Cornell is not paying me to write this article and I am also not presently involved in any research with them at the moment (I wish they did, and I wish I were!). I am an ardent eBird user and believe in the importance of data sharing and accurate data curation by the appropriate reviewer.

Literature cited

Sin, Y. C. K., Ng, D., & Kennewell, M. (2020). An unprecedented influx of vagrants into Malaysia and Singapore during the 2019–2020 winter period. BirdingASIA, 33, 142-147. Link: https://avianevonusdotcom.files.wordpress.com/2020/09/sin-et-al-2020_unprecedented-influx-of-vagrants-into-malaysia-and-singapore-2019-2020-1.pdf

Sullivan, B. L., Wood, C. L., Iliff, M. J., Bonney, R. E., Fink, D., & Kelling, S. (2009). eBird: A citizen-based bird observation network in the biological sciences. Biological Conservation, 142(10), 2282-2292. Link: https://www.researchgate.net/profile/Rick-Bonney/publication/248200195_eBird_A_citizen-based_bird_observation_network_in_the_biological_sciences/links/5747432808ae14040e28cf96/eBird-A-citizen-based-bird-observation-network-in-the-biological-sciences.pdf

Lok, A., & Subaraj, R. (2009). Lapwings (Charadriidae: Vanellinae) of Singapore. Nature in Singapore, 2, 125-134. Link: https://lkcnhm.nus.edu.sg/wp-content/uploads/sites/10/app/uploads/2017/06/2009nis125-134.pdf

Wang, L. K., & Hails, C. J. (2007). An annotated checklist of the birds of Singapore. Raffles Bulletin of Zoology Supplement, 15, 1-179. Link: https://lkcnhm.nus.edu.sg/publications/raffles-bulletin-of-zoology/supplements/supplement-no-15/

Extinction – what it means for birds in Singapore

Extinction is an evocative word, with some of the world’s most iconic birds such as the Dodo Raphus cucullatus and the Passenger Pigeon Ectopistes migratorius having achieved infamy for the dubious distinction of belonging to this category. Though the term often implies a sense of permanent loss, there are scenarios where extinction is not forever.

There are a few ways to think of the term ‘Extinct’.

The most commonly understood definition of extinction describes a complete global disappearance of a species. In Southeast Asia, no bird has been officially regarded as Extinct by the International Union for the Conservation of Nature (IUCN), though some species such as the Javan Lapwing Vanellus macropterus almost certainly are. The IUCN requires the criteria—exhaustive surveys in known and/or expected habitat, at appropriate times (diurnal, seasonal, annual), throughout its historic range have failed to record an individual—to be satisfied before concluded that a species is Extinct. This is to prevent a loss of directed conservation attention for a species that may actually be very rare rather than gone forever.

A prime example of this would be the recent extinction declaration of the Ivory-billed Woodpecker Campephilus principalis, only made after 77 years after the last confirmed sighting of this conspicuous bird. Such long lag times between last sightings of a species and a formal extinction declaration is not uncommon, especially is species that have historically had large geographic distributions.

Another category is species that are Extinct in the Wild, with all known populations of the species known only from captivity. No birds from the region officially fall into this category, though the newly split Javan Pied Starling Gracupica jalla and Javan Green Magpie Cissa thalassina may qualify with further research.

In both cases, the declaration of extinction is fairly clear-cut. If the bird can no longer be found in the wild, then it will naturally qualify for one of the two categories. However, it is when we begin to incorporate national boundaries into definitions of extinction where things begin to get hazy.

Local extinction describes a scenario where a species is extinct, or no longer occurs, within a specific portion of its geographic range. In many cases, a species may entirely vanish from a country—a situation which we describe as extirpation. Many bird species are extirpated from Singapore. For instance, both the Great Slaty Woodpecker Mulleripicus pulverulentus and Moustached Babbler Malacopteron magnirostre have not had breeding populations in the country for decades (Wang & Hails, 2007). In these cases, extirpation describes a situation where a bird is no longer a Resident Breeder; even though occasional individuals may stray into our shores from elsewhere. The lack of a breeding population precludes them from being considered re-established.

Moustached Babbler in Taman Negara, Pahang. Photo Credit: Keita Sin
Moustached Babbler in Taman Negara, Pahang. Photo Credit: Keita Sin

Record Committees (RCs) are often the local authority for declaring a bird nationally extinct. However, since national boundaries do not present actual barriers to the movement of birds, this task is much more complex than it first appears. Birds that show up unexpectedly could represent a hidden, breeding population of a very rare species or merely visitors from across the border—how does one make a case either way?

Great Slaty Woodpecker in flight, Taman Negara, Pahang. Photo Credit: Keita Sin
Great Slaty Woodpecker in flight, Taman Negara, Pahang. Photo Credit: Keita Sin

In complex cases such as this, members of the RC will have to evaluate records on a case-by-case basis, taking into account the movement and breeding ecology of the species. Many RCs additionally comprise multiple people, so as to utilise a broad swathe of expertise instead of relying entirely on the knowledge of single individuals, whose judgment may be clouded by various biases.

Let us use the previously mentioned Great Slaty Woodpecker and Moustached Babbler as examples.

Great Slaty Woodpecker perches on the side of the tree in Bukit Timah Nature Reserve. Photo Credit: Dillen Ng
Great Slaty Woodpecker perches on the side of the tree in Bukit Timah Nature Reserve. Photo Credit: Dillen Ng

In 2018, a single, Great Slaty Woodpecker was sighted within Singapore’s central forests, staying for only a short while before disappearing. Though the identification of the bird is without doubt, Great Slaty Woodpeckers are conspicuous and noisy birds (Eaton et al., 2021) — it is unlikely that an undetected population has persisted unnoticed on a small island. In addition, large woodpeckers are known to move large distances when searching for suitable foraging locations (Ogasawara et al. 1994; Garmendia et al., 2006). A single bird flying the comparatively short distance from Johor to Singapore would be unremarkable when these woodpeckers are known to fly much greater distances. As such, taking the collective evidence into account makes us suspect that the Great Slaty Woodpecker presents a case where the bird is merely a visiting individual and not part of a larger, undetected population on the island.

Moustached Babbler at Panti Forest. Photo Credit: Francis Yap

However, the ecology of the Moustached Babbler and other understory babbler species such as the Fluffy-backed Tit-babbler Macronus ptilosus is far different. Anyone who has searched for babblers can attest to their penchant for hiding in thick cover and their reluctance to move into the open. This trait suggests that most babblers do not often move across large landscapes without forest cover (Yong, 2006). In addition, the relatively short, rounded wings of most understory babblers indicate that they are poor fliers and unlikely to undertake long-distance movements (Desrochers, 2010; Hermes et al., 2016). As such, if a population of a presently unrecorded babbler species were suddenly re-discovered in Singapore, we would not suspect that these birds were visitors from abroad. However, if these birds were encountered in a site that was regularly birded, we might suspect that these birds were recent releases/escapees. Babblers are highly vocal birds with distinctive calls and would surely have been recognised by local birders had they been present as a breeding population (Eaton et al., 2021).

The Fluffy-backed Tit-babbler is an understory species that is not known to undertake long-distance movements. This individual is from Lenggor, Johor. Photo Credit: Keita Sin

As you can see, nothing is ever quite so clear cut!

These examples offer some insight into the thought processes that we might undertake when confronted by new records. Though it is a rather complex and multifaceted process, we hope that this article makes what seems like a rather opaque and fuzzy process much more understandable!

References

Desrochers, A. (2010). Morphological response of songbirds to 100 years of landscape change in North America. Ecology 91: 1577–1582. doi: 10.1890/09-2202.1

Eaton, J. A., van Balen, S., Brickle, N. W., & Rheindt, F. E. (2021). Birds of the Indonesian Archipelago: Greater Sundas and Wallacea (Second Edition). Lynx Edicions, Barcelona.

Garmendia, A., Cárcamo, S., & Schwendtner, O. (2006). Forest management considerations for conservation of black woodpecker Dryocopus martius and white-backed woodpecker Dendrocopos leucotos populations in Quinto Real (Spanish Western Pyrenees). In Forest Diversity and Management (pp. 339-355). Springer, Dordrecht. Link

Hermes, C., Döpper, A., Schaefer, H. M., & Segelbacher, G. (2016). Effects of forest fragmentation on the morphological and genetic structure of a dispersal-limited, endangered bird species. Nature Conservation16, 39. Link

Ogasawara, K., Izumi, Y., & Fujii, T. (1994). The status of black woodpecker in Northern Tohoku District, Japan. Journal of the Yamashina Institute for Ornithology, 26(2), 87–98. Link

Extinction – what it means for birds in Singapore

Yong, D. L., (2006). Preliminary list of larger vertebrates in Panti Forest Reserve, South Johore. Singapore Avifauna, 20(1): 26–35. Link

 

 

 

 

 

 

Bird List Revision for September 2021 – Special Edition

The Singapore Birds Project checklist is updated regularly according to taxonomic updates by the International Ornithological Committee (IOC). Our team recently conducted a thorough review to vote on additional species to be added to or removed from the checklist. In the spirit of ensuring that accurate information is provided in a timely fashion, we decided to release a Special Edition prior to the next IOC update. The downloadable list (in Excel format) is available HERE.

Along with this update, we would like to welcome Raghav to the team. Our growing Singapore Birds Project main team consists of Keita Sin (chair), Sandra Chia (vice-chair), Dillen Ng, Francis Yap (site admin), Movin Nyanasengeran and Raghav Narayanswamy. Many of you have provided us generous comments for our work which we are very grateful for. Suggestions and constructive criticisms, as always, are strongly welcome! Please feel free to reach out to us via the Contact Us section.

A write-up of how our checklist operates will be released soon. In the mean time, here are the details for the changes to the checklist.

Added

Orange-breasted Green Pigeon: A vagrant to Singapore with a single record of a male from Japanese Garden on 22 December 2007.

Masked Lapwing: This species native to Australia has breeding records dating back to at least 2004. The growing population seems to be sustainable and recent sightings include a flock of ~50 birds along a canal in Bedok.

Javan Plover: A single, very likely breeding record from Pulau Tekong in mid-2021. More records of this expanding species might be expected in the near future.

Milky Stork and Painted Stork: Both species of storks have been introduced to Singapore since at least 1987. Their breeding is indicated by ever-present juveniles at multiple sites in Singapore coupled with the numerous nests around Mandai. A recent genomic analysis by Baveja et al (2019) revealed an alarming result that many of the storks in Singapore are hybrids at some level. However, some genetically pure Milky Stork still exists. The Painted Storks sampled in the study were at best backcrosses between first generation hybrids and pure ones, but this species is also added to the checklist on balance that evidence suggest the presence of pure individuals.

Pied Kingfisher: A single record from Punggol on 18 September 1995. The same species was recorded at Southern Johor in early 2016 as well.

Crimson-winged Woodpecker: Sightings from Bukit Timah in 2001, at least one of which was accompanied by sketches. Several other reports continuing up to 2008 are unsubstantiated thus far.

Monk Parakeet: This species is native to South America and has been present since at least 2009, with nesting records dating back to 2012. The presence of multiple breeding records coupled with the recent westward expansion is indicative of an alarming population growth.

Velvet-fronted Nuthatch: Multiple sightings of a single individual in Bukit Timah from 1996 to 1999. A non-breeding visitor to Singapore.

Red-billed Starling: A total of four records in Singapore. While the provenance of each specific record remains to be assessed, increasing evidence of vagrancy from Indochina and the Philippines are indicative that wild birds occur in Singapore.

Golden-backed Weaver: The proliferation of this species in suitable habitats has been highly visible. Strongholds at Kranji Marshes and Lorong Halus show that this species is clearly well-established. The obvious displacement of native Baya Weavers is worrying.

Deleted

Yellow-crested Cockatoo: This introduced species only occurs in small numbers in Singapore, indicative that there is a lack of a self-sustaining population. Multiple reports of hybridising Yellow/Sulphur x Tanimbar Cockatoos are also strongly suggestive that individuals are struggling to find mates from their own species. Moreover, Sulphur-crested Cockatoos are more numerous than this species.

The following species were deleted from our checklist on the basis that there have not been any conclusive records in the nation for over 30 years.

Eurasian Teal, Dunlin, Roseate Tern, Hen Harrier, Plain Sunbird, Yellow-breasted Bunting, Eurasian Woodcock, Blyth’s Hawk-Eagle, Oriental Hobby

Shifted to Annex

This category houses species that have been recorded in the vicinity of Singaporean waters in the past 30 years. One should keep a lookout as there is a chance that these birds can be encountered within our national boundaries during pelagic trips. We keep an open mind about pelagic species and consider both quantitative (GPS coordinates) and qualitative evidences (descriptions of the sighting and ecological background of the species) when assessing such birds.

Lesser Black-backed Gull: A record from 20 November 2011 along the Singapore Straits with an unfortunate lack of GPS coordinates nor detailed descriptions.

Christmas Frigatebird: A single record outside Singapore waters from 4 May 2013.

References

Baveja, P., Tang, Q., Lee, J. G., & Rheindt, F. E. (2019). Impact of genomic leakage on the conservation of the endangered Milky Stork. Biological Conservation, 229, 59-66.

An Indonesian Archipelago Wishlist: Birds to Look Out For

The recent sighting of the Javan Plover Charadrius javanicus at a reclaimed site northeast of Singapore island was exciting yet unsurprising. Exciting because it was a first for Singapore and continental Southeast Asia that caught everyone off guard (then again, none of us are really prepared for megas!) and unsurprising because this is a species whose range has been slowly expanding over the years (Iqbal et al., 2011; Eaton et al., 2021). The appearance, and likely breeding of this species is highly relevant to recent changes in regional avifauna, especially when taking into account the first breeding records for the Pied Stilt Himantopus leucocephalus and Black-winged Stilt H. himantopus that were documented at the same site in 2019 and again this year, respectively.

Apart from the Javan Plover, several other species traditionally known to be from the Indonesian Archipelago (that comprises Sumatra, Borneo, Java and other Indonesian islands west of the Wallace Line) could potentially be found in Singapore and the neighbouring regions. Here are the distinguishing features of the Javan Plover and seven other species readers can keep an eye out for!

Javan Plover Charadrius javanicus

This species closely resembles the Kentish Plover, a locally uncommon migrant. Features including warm buff ear-coverts and relatively heavier bill and longer legs point to the Javan Plover. For those keen to learn more, detailed distinguishing features are described in Iqbal et al. (2013). Other regular plovers in Singapore can be distinguished by a combination of several other features. Lesser and Greater Sand Plovers have incomplete white-bands on their neck, Malaysian Plover have more “sandy-looking” upperparts, and White-faced Plover has a plain looking face as its name suggests.

Wandering Whistling Duck Dendrocygna arcuata

Although this species used to be an uncommon introduced species (Wang & Hails, 2007), the last local sighting was in 2016 (eBird) and the feral population has likely crashed for good. Being highly dispersive, wild birds could possibly wander here in due time. In fact, there is a record from Perak, Malaysia, that may conceivably be of wild provenance (but note that the current status of this species in Peninsula Malaysia is also introduced). It can be distinguished from the locally uncommon Lesser Whistling Duck by its lack of yellow eye ring and distinct white flanks.

Sunda Teal Anas gibberifrons

A species that seems to be undergoing a rapid range expansion across Borneo, Sulawesi and Sumatra (Eaton et al., 2016; 2021; Iqbal, 2016; MNSBCC Records Committee, 2016). With records in Sumatra not too far from Singapore, this funny looking duck might make its way here in the near future. It is much darker and browner than the local Whistling Ducks, with a distinct bulge on the male’s forehead. It prefers brackish water although other wetland habitats are also possible sites to look out for this species. Although various breeds of domestic ducks have been released in Singapore, these typically look more Mallard-like, with variable amount of colouration on their heads and wingpanels. Having said that, most if not all wild ducks in Singapore are typically worth celebration, so if in doubt of identification, it’s best to share the sighting for confirmation.

Black-backed Swamphen Porphyrio indicus

Swamphen taxonomy is rather incongruent, with much left to be discovered (Garcia-R & Trewick, 2015; Callaghan et al., 2020; Eaton et al., 2021; Gill et al., 2021). Records from Singapore are thought to be the Grey-headed Swamphen viridis (Wang & Hails, 2007; Callaghan et al., 2020), but possible integrades have been recorded before locally (Wells, 1990). The distribution of the Black-backed Swamphen is also contentious especially on Sumatra, with the two forms likely mixing (Wells, 1999; Taylor, 2020; Eaton et al., 2021). The Grey-headed Swamphen is another species struggling to survive in Singapore – a common theme for local waterbirds – and was last seen in 2018 (eBird). But if you do happen to see one, be sure to check its back colour. Black-backed Swamphen can be distinguished by having darker upperparts and face.

Australasian Grebe Tachybaptus novaehollandiae

The Australasian Grebe is capable of undertaking overwater dispersals (Llimona et al., 2020). Recent new records from Sulawesi and southern Sumatra (Eaton et al., 2016; Eaton et al., 2021) suggest a possible range expansion underway. Its habitat requirements are similar to the locally rare Little Grebe Tachybaptus ruficollis from which it can be distinguished by its darker neck and ear coverts. Given that the Little Grebe is already struggling to survive in Singapore at the moment, the chances of the Australasian Grebe breeding here like the plovers did are probably low, but they’re certainly worth looking out for.

Little Black Cormorant Phalacrocorax sulcirostris

Another species that seems to be experiencing a spread across the Sumatran coast (Eaton et al., 2021). Waterbodies – both coastal and inland – are potential locations to find this species. Locally, escaped individuals of the Great Cormorant and Little Cormorant have been documented (Wang & Hails, 2007). There were apparently two local records of the Little Black Cormorant as well in August and September 1993 (Oriental Bird Club, 1994; Lim, 2009). Assessing the provenance of cormorants can be a challenge in Singapore so do try to obtain high quality images of them (especially the legs) if you find one.

Little Egret Egretta garzetta nigripes

Knowledge on the distribution of this taxon in our region is far from ideal. Present from Indonesia through eastern Australia, it seems to be spreading across Sumatra (Iqbal, 2012; del Hoyo et al., 2020; Eaton et al., 2021). Their local status varies from “uncommon”, “sparing” to “probable” (Wang & Hails, 2007; Robson, 2014; Puan et al., 2020) and there is still much for us to document. Possible integrades have been seen in Singapore too. Various bare part colouration distinguishes this taxon apart from the locally common migrant Little Egret garzetta (Bakewell, 2019), perhaps most distinct among them being their toe colour – black in nigripes, yellow in garzetta in breeding plumage (images 14 & 15). However, caution should be taken during identification as juveniles and non-breeding garzetta can have duller feet and mud can affect feet colour (Robson, 2014).

 

Sacred Kingfisher Todiramphus sanctus

This species breeds in Australia and is a highly likely contender for showing up on Singapore given that it is an Austral migrant to Borneo and Indonesia, similar to the Horsfield’s Bronze-cuckoo Chrysococcyx basalis. Multiple people have claimed an encounter with this species in Singapore and it is also listed to be present in Robson (2014). However, none of the records have been adequately substantiated and a record from Thailand in February 2019 (Round et al., 2020) is the only formal record in our region thus far. The Sacred Kingfisher can be distinguished from the Collared Kingfisher T. chloris by its turquoise upperparts (as opposed to blue), smaller overall size and bill, and buff wash on its lores and flanks. Care is required in distinguishing this species from immature Collared Kingfishers as they can show some buff wash as well, but typically with scalloped plumage on their breast.

Acknowledgements

Huge thanks to Dave Bakewell, James Eaton and Khaleb Yordan for identification discussions on the Javan Plover identification online, as well as others we had offline. I would also like to express my gratitude to Frankie Cheong for documenting and sharing pictures of Singapore’s first Javan Plover, to the Singapore Birds Project team (Dillen, Francis, Movin, Raghav, Sandra) for comments on this article and to the following for sharing their excellent photos: Dillen Ng, Geraldine Lee, Goh Cheng Teng, Khaleb Yordan and Lim Hong Yao.

Literature Cited

Bakewell, D. (2019). The Chinese Egret Egretta eulophotes: identification revisited. BirdingAsia, 31, 14-23.

Callaghan, C. T., Pranty, B., Pyle, P., & Patten, M. A. (2020). Gray-headed Swamphen (Porphyrio poliocephalus), version 1.0. In Rodewald, P. G. & Billerman, S. M. (Eds.), Birds of the World. Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.purswa3.01

del Hoyo, J., Martínez-Vilalta, A., Motis, A., Collar, N., Kirwan, G. M., & Christie, D. A. (2020). Little Egret (Egretta garzetta), version 1.0. In Billerman, S.M., Keeney, B.K., Rodewald, P.G. & Schulenberg, T.S. (Eds.), Birds of the World. Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.litegr.01

Eaton, J. A., van Balen, S., Brickle, N. W., & Rheindt, F. E. (2016). Birds of the Indonesian Archipelago: Greater Sundas and Wallacea. Lynx Edicions, Barcelona.

Eaton, J. A., van Balen, S., Brickle, N. W., & Rheindt, F. E. (2021). Birds of the Indonesian Archipelago: Greater Sundas and Wallacea (Second Edition). Lynx Edicions, Barcelona.

Garcia-R, J. C., & Trewick, S. A. (2015). Dispersal and speciation in purple swamphens (Rallidae: Porphyrio). The Auk: Ornithological Advances132(1), 140-155. Link: https://academic.oup.com/auk/article/132/1/140/5149144?login=true

Gill, F., Donsker, D. & Rasmussen, P. (Eds). (2021). IOC World Bird List (v11.2). doi:10.14344/IOC.ML.11.2

Iqbal, M., Febrianto, I., & Zulkifli, H. (2011). The occurrence of the Javan Plover Charadrius javanicus in Sumatra, Indonesia. Wader Study Group Bulletin, 118(2), 131-133.
Link: https://www.researchgate.net/publication/293205017_The_occurrence_of_the_Javan_Plover_Charadrius_javanicus_in_Sumatra_Indonesia

Iqbal, M., Nurza, A. & Giyanto. (2012). Breeding Records of Little Egret Egretta garzetta in Sumatra, with notes on the occurence of race E. g. garzettaKukila16, 59-63.
Link: https://www.researchgate.net/publication/315912527_Breeding_Records_of_Little_Egret_Egretta_garzetta_in_Sumatra_with_notes_on_the_occurence_of_race_E_g_garzetta

Iqbal, M., Taufiqurrahman, I., Gilfedder, M., & Baskoro, K. (2013). Field Identification of Javan Plover Charadrius javanicusWader Study Group Bulletin120(2), 96-101.
Link: https://www.researchgate.net/publication/262562330_Field_identification_of_Javan_Plover_Charadrius_javanicus

Iqbal, M. (2016). Status of Sunda Teal Anas gibberifrons in South Sumatra. Kukila19, 30-33.
Link: https://www.researchgate.net/publication/316075498_Status_of_Sunda_Teal_Anas_gibberifrons_in_South_Sumatra

Lim, K.S. (2009). The Avifauna of Singapore. Nature Society (Singapore), Singapore.

Llimona, F., del Hoyo, J., Christie, D. A., Jutglar, F., Garcia, E. F. J., & Kirwan, G. M. (2020). Australasian Grebe (Tachybaptus novaehollandiae), version 1.0. In del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (Eds.), Birds of the World. Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.ausgre1.01

MNSBCC Records Committee. (2016). Latest News 22 November 2016. MNSBCC Records Committee. Retrieved 28 August 2021 from https://sites.google.com/site/mnsbccrecordscommittee/Home/latest-news

Oriental Bird Club. (1994). From the field. Oriental Bird Club Bulletin, 19, 65-67.
Link: https://www.biodiversitylibrary.org/item/253243#page/69/mode/1up

Puan, C.L., Davison, G. & Lim, K.C. (2020). Birds of Malaysia. Lynx Edicions, Barcelona.

Robson, C. (2014). Field guide to the birds of South-East Asia (Second Edition). Bloomsbury Publishing, London.

Round, P D., Jahan, I., Thompson, P. & James, D. J. (2020). Mainland Asia’s first record of Sacred Kingfisher Todiramphus sanctus. BirdingAsia, 34, 123-127.

Taylor, B. (2020). Black-backed Swamphen (Porphyrio indicus), version 1.0. In Rodewald, P.G. (Eds.), Birds of the World. Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.purswa4.01

Wang, L. K., & Hails, C. J. (2007). An annotated checklist of the birds of Singapore. Raffles Bulletin of Zoology15, 1-179.
Link: https://lkcnhm.nus.edu.sg/wp-content/uploads/sites/10/app/uploads/2017/04/s15rbz001-179.pdf

Wells, D.R. (1990). Malayan Bird Report: 1986 and 1987. Malayan Nature Journal, 43, 172-210.

Wells, D. R. (1999). The birds of the Thai-Malay peninsula (Vol. 1). Academic Press, London.

Nesting Malaysian Plovers

By Goh Cheng Teng
Edited by Keita Sin & Lester Tan

The Malaysian Plover Charadrius peronii is a small shorebird that inhabits coastal sandy areas and rocky shores. It is the only resident breeding plover in Singapore island and can be reliably found along the man-made seawall at Marina East. They are classified globally as Near Threatened (BirdLife International, 2017) and locally as Threatened (Lim, 2009).

A Chick!

On the morning of Sunday 27 June 2021, Lester Tan and I were walking along the Marina East seawall when we were halted by a soft twik from a male Malaysian Plover to our front. This was highly unusual as the Malaysian Plovers at Marina East do not typically vocalise, preferring instead to scurry away in silence.

With this thought at the back of our minds, we started scanning the area, locating a female Malaysian Plover slightly behind and below us in short order. We soon spotted movement from the female’s direction, which turned out to be an extra set of legs belonging to a very new Malaysian Plover!

As we approached slowly for better photographs, the female Malaysian Plover brooded the chick for a while (image 1) before running off, presumably to distract us from the chick. We kept our distance and the chick waited a while before getting up to follow the parent (image 2).

Growing up

Over the next three Sundays, we revisited Marina East to document the chick’s progress (image 3). Each time, we were first greeted by the soft twik of the male Malaysian Plover a distance away from where we would eventually find the female and the chick.

On 4 and 11 July, the weather over Singapore was rainy and the chick was regularly brooded by an adult, probably to aid in regulating body temperature (image 4). By 18 July, the chick had grown discernibly larger. While we did not witness brooding, it still sought cover from threats. Chicks of the Malaysian Plover are precocial and are never fed by parents (Yasué & Dearden, 2008) but we also could not observe any feeding behaviour.

Camouflage and Chick Defense

When disturbed, the chick tucked itself into the nooks and crannies of the seawall. Its mottled brown, white and black plumage provided camouflage while it nestled itself against pieces of marine debris (image 5). We also observed it hiding in grass adjacent to the seawall.

As long as we remained stationary at distance, one of the adults, typically the female, would eventually approach the chick while vocalising a series of soft twiks. The chick would then get up and follow the adult. We did observe brooding by the male as well, though less frequently.

While plovers are among the group of birds known for using the “broken-wing display” in response to disturbances (Gómez-Serrano & López-López, 2017), we did not observe this behaviour. We only observed them vocalising and attempting to lead us away from the chick whenever we ventured too close. Sometimes, an adult approached us while vocalising.

On one occasion when a flock of crows roosted nearby, the chick went into hiding while the adults kept watch from a distance. We observed an adult flying out to sea when dived on by individual crows although it returned to the site shortly after. However, when disturbed by humans, the adults did not fly off and always stayed within visible distance.

Fledged?

On Sunday 25 July 2021, we made our way to Marina East again. This time however, there was no twik greeting from the male Malaysian Plover. The female was nearby bathing and preening in one of the puddles atop the seawall. The pair of Malaysian Plovers had seemingly reverted to their typical non-vocalizing and more confiding selves, and the chick was nowhere to be found. The absence of the chick had been noted the day before, with adults reportedly being skittish (Francis Yap, pers. comms.).

The chick was independently discovered by Max Khoo a day before us on 26 June (pers. comms.), and would have been at least 28 days old, within the fledging window of 27-33 days after hatching (Wiersma et al., 2020). Unfortunately, we later found out that the plovers were preyed upon by a House Crow Corvus splendens, putting the journey of the young bird to an end.

Nest Habitat and Conservation

Malaysian Plovers nest in coastal locations that typically include an intertidal mudflat for foraging, a sandy beach for nesting, and a shrubby vegetated area that can provide cover for chicks during disturbances (Yasué & Dearden, 2008). Natural habitats suitable for the nesting of the Malaysian Plover are declining locally due to developments. However, many local nesting records have been on reclaimed land and coastal defense structures – they have previously been documented laying their eggs on the seawall (image 6; Nicholas Lim, pers. comms.).

The diet of the Malaysian Plover is poorly known (Wiersma et al., 2020) but we have observed them foraging on algal cover on the seawall where they appear to feed on invertebrates, or perhaps even microorganisms. Interestingly, they are rarely observed feeding on the adjoining mudflat where other waders have been observed.

Across five weekends of observations, this was the only family of Malaysian Plovers sighted along the entire stretch of the Marina East seawall. During the migratory season, presumably a non-breeding period, there would typically be more Malaysian Plovers scattered along the seawall, including multiple male and female birds. Their highly territorial behaviour (Yasué & Dearden, 2008) likely makes it difficult for multiple pairs to share the territory when nesting.

Our observations suggest that the plovers might be adaptable to nesting on artificial structures, provided that areas necessary for food, egg-laying and cover are present. Locally, breeding has been recorded in March-April (Lim, 2009) and July-September (BESG, 2006; Goh, 2016), as well as in June this year (Raghav Narayanswamy, pers. comms.).

The presence of these pockets of breeding habitat are crucial to the continued presence of the Malaysian Plover in Singapore. Protection and management of such areas from human intrusion during the breeding season where the birds are most sensitive to disturbances can be considered.

Acknowledgements

Warm thanks to Francis, Max and Raghav for insights about their breeding, to Nicholas for sharing his photo and to the SBP team (Dillen, Movin, Sandra) for comments.

References

BESG. (2006). Malaysian Plover 2: Nesting. Bird Ecology Study Group. Retrieved 26 July 2021, from https://besgroup.org/2006/07/25/malaysian-plover-2-nesting/

Goh, C.T. (2016). Out of Season Breeding of the Malaysian Plovers in Singapore. Nature Society (Singapore) Singapore Bird Group. Retrieved 26 July 2021, from https://singaporebirdgroup.wordpress.com/2017/10/24/out-of-season-breeding-of-the-malaysian-plovers-in-singapore/

Gómez-Serrano, M.A., & López-López, P. (2017). Deceiving predators: linking distraction behavior with nest survival in a ground-nesting bird. Behavioral Ecology, 28(1), 260–269.
Link: https://academic.oup.com/beheco/article/28/1/260/2453523

BirdLife International. (2021). Species factsheet: Charadrius peronii. Retrieved 26 July 2021, from http://datazone.birdlife.org/species/factsheet/22693836

Lim, K.S. (2009). The Avifauna of Singapore. Nature Society (Singapore). Singapore.

Wiersma, P., Kirwan, G. M., & Boesman, P. F. D. (2020). Malaysian Plover (Charadrius peronii), version 1.0. In J. del Hoyo, A. Elliott, J. Sargatal, D. A. Christie, and E. de Juana (Eds.), Birds of the World. Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.malplo1.01

Yasué, M. & Dearden, P. (2008). Parental sex roles of Malaysian Plovers during territory acquisition, incubation and chick-rearing. Journal of Ethology, 26(1), 99-112.Link: https://www.researchgate.net/profile/Philip-Dearden/publication/225332000_Parental_sex_roles_of_Malaysian_Plovers_during_territory_acquisition_incubation_and_chick-rearing/links/00b7d528dc22588a11000000/Parental-sex-roles-of-Malaysian-Plovers-during-territory-acquisition-incubation-and-chick-rearing.pdf

Gallery

Bird List Revision for July 2021

The latest revision of the Singapore Bird List is now derived from IOC World Bird List Version 11.2. The downloadable list (in Excel format) is available HERE.

The following are the major changes:

Addition: Wedge-tailed Shearwater – First record of a single bird at Woodlands on 22 June 1998, second record of a single bird at Bishan Ang Mo Kio Park on 23 June 2021.
Addition: Malayan Black Magpie – First record of a single bird at Hindhede Nature Park on 9 June 2021.
Addition: Siberian House Martin – First record of a single bird at Neo Tiew Harvest Lane on 3 January 2021.

Along with the checklist update we are happy to introduce new members to the Singapore Birds Project team. Dillen, Keita, Movin and Sandra will be contributing ideas through articles and the checklist management. We take pride in ensuring that the checklist is regularly, accurately and transparently updated. Please feel free to drop any of us a message if you have any queries or suggestions!

Photo: Siberian House Martin, by Mike Hooper

Measurements of the 23 June 2021 Wedge-tailed Shearwater in Bishan

Pelagic birds are rather scarce in Singapore, so news of the grounded Shearwater found at Bishan-Ang Mo Kio Park on 23 June must have caught everybody by surprise. The bird was originally found by a passer-by below a HDB block in the area and then transported to the park. It was later spotted by William Khaw, who alerted the birdwatching community and ACRES. Many others contacted ACRES as well but despite being rescued, the bird did not survive. I was fortunate enough to take a look at the bird’s carcass with my colleagues and managed to get some measurements that are reproduced below. While photographs of the bird are aplenty online, I hope that these numbers will help serve as primary documentation for future birders as well as help those still wavering on the identification.

FeatureMeasurements of the Bishan bird (mm)Measurements (mm) of Wedge-tailed Shearwaters (WT) and Short-tailed Shearwaters (ST)
Tail119.0WT: 123-138
ST: 78-85
(Pettit et al., 1984; Longmore, 1985; Wells, 1999).
Bill depth at base11.3 –
Bill depth at nare (tip of the nostril)10.2 –
Minimum bill depth7.4 –
Bill to skull46.5 –
Bill to feathers39.0WT: 38.47±1.89
ST: 31.82±1.37
(Bull et al., 2005)
Head plus bill81.8 –
Wing279.0WT: 292.99±9.99
ST: 267.11±13.06
(Bull et al., 2005)
Tarsus47.3 –
Mid-toe (including claw)58.5 –
Mid-toe (without claw)50.7 –

The Wedge-tailed Shearwater Ardenna pacifica can be distinguished from the more locally expected (though still rare) Short-tailed Shearwater A. tenuirostris from a number of features. These include the bill shape (comparatively long bill to head ratio) and the tail extension (long in Wedge-tailed Shearwater, shorter in Short-tailed Shearwater). For those who are less familiar, comparison of the measurements against other sources unequivocally confirm the identification as a Wedge-tailed Shearwater; the similar looking Short-tailed Shearwater measures much smaller.

Of the three species of Shearwaters that have been recorded regionally so far, the Short-tailed Shearwater is the most expected around the nation. Although a rare bird locally, it has been reported semi-regularly in recent years along the Singapore Straits during pelagic trips (https://ebird.org/species/shtshe). Instead, there is only one record of the Wedge-tailed Shearwater so far, yet another grounded bird that was photographed at Woodlands on 22 June 1998 (Wang & Hails, 2007). Coincidentally just 1 day apart, although 23 years ago! The third species, Streaked Shearwater Calonectris leucomelas is expected, though no verifiable records are present as of yet.

If you find any wild animal that needs help, please contact ACRES at 97837782 and/or the NParks hotline at 18004761600.

Acknowledgements

Massive thanks to the staffs at ACRES, especially Kalai and Ava, who helped keep and pass the carcass to the NUS Avian Evolution Lab, to all who assisted in the rescue process, and to William Khaw for sharing the sighting with the community. I would also like to express my gratitude to Art Toh, Dillen Ng, Martin Kennewell, Movin Nyanasengeran and Tan Hui Zhen for the help in preparing this short piece.

Literature cited

Bull, L. S., Bell, B. D., & Pledger, S. (2005). Patterns of size variation in the shearwater genus Puffinus. Marine Ornithology, 33, 27-39. Link: http://www.marineornithology.org/PDF/33_1/33_1_27-39.pdf

Longmore, N. W. (1985). Two new records of the short-tailed shearwater from north Queensland. Sunbird: The Journal of the Queensland Ornithological Society, 15(4), 84. Link: https://birdsqueensland.org.au/sunbird_issues/Sunbird_Vol15_No4.pdf

Pettit, T. N., Byrd, G. V., Whittow, G. C., & Seki, M. P. (1984). Growth of the Wedge-tailed Shearwater in the Hawaiian Islands. The Auk, 101(1), 103-109. Link: https://sora.unm.edu/sites/default/files/journals/auk/v101n01/p0103-p0109.pdf

Wang, L. K., & Hails, C. J. (2007). An annotated checklist of the birds of Singapore. Raffles Bulletin of Zoology, 15, 1-179. Link: https://lkcnhm.nus.edu.sg/wp-content/uploads/sites/10/app/uploads/2017/04/s15rbz001-179.pdf

Wells, D. R. (1999). The birds of the Thai-Malay peninsula (Vol. 1). London: Academic Press.

Bird List Revision for January 2021

The latest revision of the Singapore Bird List is now derived from IOC World Bird List Version 11.1. The downloadable list (in Excel format) is available HERE.

The following are the major changes:

  1. Addition: Common Swift – First record of a single bird on 9 October 2020 at Jelutong Tower, Central Catchment Nature Reserve. Second record of a single bird on 27 October 2020 at Henderson Waves.
  2. Addition: Hair-crested Drongo: – First record of a single bird seen at Changi Business Park on 26 November 2019.
  3. Taxonomic change: Resequence Family Anatidae (Ducks, Geese, Swans) to come before Family Phasianidae (Pheasants & Allies) in accordance to standard sequencing protocol adopted elsewhere.