We have added 31 species to our new migrant bar charts in the last two weeks, which can be accessed HERE. They will continue to be released in batches over the coming months. To learn more about these, you can read our summary blog post.
We have added 21 species to our new migrant bar charts, which can be accessed HERE. They will continue to be released in batches over the coming months. To learn more about these, you can read our summary blog post.
Our new migrant bar charts can be accessed HERE. They will be released in batches, with the first few posted today (25 Aug).
Have you ever asked when you should expect to start seeing warblers and flycatchers make their way to Singapore, or when to start watching the skies for the fall raptor migration?
Our bar charts for rarities were released early this year, and we trust that it has been a useful tool for many in deciding when and where to look for mega targets. After making them public, we decided to dream bigger: why not do it for all migratory species in Singapore so that everybody can learn more? In the coming weeks, we will be launching bar charts for all migrant and vagrant species (not just rarities), illustrating the estimated number of individuals that are typically present in Singapore during different times of the migratory season. These charts will also highlight the peak weeks, as well as early and late dates for relevant species (only possible for species which do not have oversummering records).
Our charts will be rolled out and launched on our website progressively based on the typical arrival times of each species.
Data used is based on the period Jul 2012-Jun 2022, and will be updated at the end of every season so it remains relevant over time.
Use this page to access our bar charts, or keep reading below for a more detailed overview of how they are produced.
How we generate our estimates
For species in our database, this is relatively straightforward. We split each year into 52 weeks, starting from Jan 1, and count up the number of birds in each week according to records in our database.
It is a more involved process when it comes to estimating numbers for species not included in our database.
Briefly, the process includes:
Grouping all the sightings into their corresponding weeks
Using distance between sightings to determine whether two sightings may be linked (i.e. the same birds involved)
Using time between the sightings grouped in step 2, to further determine whether they are linked
Concluding by lumping those sightings which are linked, and splitting those which are not, to give an estimate of the number of birds present at any one point in time
This procedure is necessary to account for duplicated records as not every observer uses the same eBird “hotspots”, and some users may use “personal locations” to record sightings rather than hotspots. This may result in a distance of a few kilometres between eBird observations that might refer to the same bird.
At the same time, different species may require different methods of determining whether two sightings are of the same bird. A raptor which is passing through Singapore is unlikely to be seen on multiple days in a row – two Common Kestrels at Henderson Waves on consecutive days in October, for example, are likely different individuals. Our approach, which combines spatial and temporal methods to estimate the number of individuals of a species during each week, is relatively tolerant to these complicating factors.
Ever wondered what rare gems were found in Singapore on this day in past years? With the Singapore Birds Project’s new On this day page, you can do just that.
Drawing on our collection of nearly 1,500 records and counting, this page highlights past records on this day in history. As always, every record is accompanied by details and photos where possible.
We hope this will be a valuable resource for birders keen to find megas not seen lately (like this White-throated Rock Thrush, recorded at Bukit Timah Nature Reserve on this day 11 years ago).
And as always, we’re working to develop more similarly useful tools for the community, so stay tuned, and happy birding!
The latest update of our checklist, version 2022-1, has been published. It can be accessed at our Downloads page.
Since the last bird list revision in September 2021, our team has voted on over 100 records of rare species in Singapore. Although our latest votes are always available at our Recent Decisions page, we will continue to publish regular updates to keep our readers updated on the latest avifaunal developments, including recent advances in taxonomy.
Along with this update, we are also launching a live version of our checklist! For the past six years, the Singapore Birds Project has published checklists every half a year. However, with the growth in observer effort and information available, the combined knowledge of Singapore’s birding community is rapidly increasing. Within a short span of five months since our last checklist update, the checklist has seen a net gain of seven species. We will continue to release half-yearly checklist updates in Excel format, but latest developments can be tracked in the live checklist.
Our downloadable checklist now also comes with new information on each species, including status in the Singapore Red Data Book, as well as rarity status (based on our Rarities List), local status, checklist category, and links to our Singapore Bird Database for relevant species.
Added to checklist
Ashy-headed Green Pigeon Treron phayrei [Record 10001]: The committee deliberated extensively on this bird recorded at Dillenia Hut from 9 to 11 Oct 2021. This species is not known to occur south of the Isthmus of Kra, with no records in Malaysia, but Treron pigeons are known to wander widely in search of fruit sources. The final decision was to accept the individual as a wild bird and place the species in Cat A (for species that have occurred naturally in the wild within the last 30 years), a thorough discussion of this record is available in this article and at the link above.
Ashy-headed Green Pigeon at Central Catchment Nature Reserve. Photo credit: Yip Jen Wei
Spotted Flycatcher Muscicapa striata [Record 10002]: One record at Kent Ridge Park from 15-29 Oct 2021. While there are recent records in the Philippines and Taiwan, this is the first record for continental Southeast Asia. The committee voted unanimously to place this species in Cat A.
Tree Pipit Anthus trivialis [Record 10005]: A single bird off Clementi Road, 19-31 Oct 2021. Like the Spotted Flycatcher, this species is a long-distance migrant with most of the population wintering in India and Africa. Regarded as a vagrant and placed unanimously in Cat A.
Tree Pipit at Clementi. Photo credit: Francis Yap
Common Starling Sturnus vulgaris[Record 10082]: One record of a single bird at Marina East Drive from 13 to 15 Dec 2021. A known vagrant with records in Malaysia and further north, as well as Borneo, but this is the first national record. Placed in Cat A on a unanimous vote.
Black Redstart Phoenicurus ochruros [Record 10069]: One record at Pasir Panjang, first seen on 28 Nov 2021 and subsequently by many observers; still present as of Feb 2022. Age, sex, and subspecies remain unclear as of writing, but further observation of the bird may provide more insight. Regarded as a vagrant and unanimously placed in Cat A.
Black Redstart at Springwood Crescent. Photo credit: Francis Yap
Cinereous Vulture Aegypius monachus [Record 10106]:A vagrant individual with Himalayan Griffons Gyps himalayensis at Singapore Botanic Gardens, 29-30 Dec 2021; subsequently found weak and unable to fly near Holland Road. Rescued, rehabilitated, and released early this year. Placed in Cat A on a unanimous vote.
Pale-legged Leaf Warbler Phylloscopus tenellipes [Record 10030]: One record of a vagrant present from 12 Nov to at least 3 Dec 2021 at Macritchie Reservoir was unanimously accepted and the species placed in Cat A. This species is a regular winter visitor to Thailand but is believed to be rarer than the visually identical Sakhalin Leaf Warbler P. borealoides further south in the peninsula.
Previous records not accepted, but species maintained in checklist
Grey-streaked Flycatcher Muscicapa griseisticta [Record 10032; Record 748]: A previous record in April 1991 was reviewed by the committee and not accepted as the descriptions provided do not conclusively rule out Dark-sided Flycatcher M. sibirica. However, a single bird present from 9-17 Nov 2021 was accepted as the first national record and the species was therefore retained in the checklist in Cat A.
Scarlet-breasted Flowerpecker Prionochilus thoracicus [Record 10056; Record 10055]: Upon review by the committee, a record from 1 Jan 2015 was not accepted due to lack of supporting evidence. The record of an individual at Bukit Timah Nature Reserve on 29 Nov 2021 was, however, accepted and the species was retained in the checklist in Cat A.
Considered for inclusion
Long-eared Owl Asio otus [Record 10042]: After much deliberation, the committee decided on a split vote that the single sighting of this bird at Marina East Drive on 20 Nov 2021 most likely pertained to a ship-assisted individual rather than a wild bird. For more detailed discussion of this record, see the record linked above. Removed from checklist
Temminck’s Stint Calidris temminckii [Past records]: As the last record of this species in Singapore was in Oct 1984, it exceeds the 30-year threshold for inclusion in the checklist. The committee placed this species in Cat B1 (for species which would appear in Cat A, but without records within the last 30 years).
Eurasian Coot Fulica atra [Past records]: Like Temminck’s Stint, this species has not been recorded locally in the last 30 years and was therefore assigned to Cat B1 and removed from the checklist.
Still pending review
Christmas Frigatebird Fregata andrewsi[Record 10163]: A record in May 2013 was outside Singapore’s territorial waters; the most recent confirmed record within Singapore’s geographical boundaries was in May 1986, which exceeds the 30-year threshold for inclusion in the checklist. If the record from Marina East Drive (see record linked above) is accepted, the species would be moved from the Annex to Cat A.
Other minor change
Stejneger’s Stonechat is renamed to Amur Stonechat following taxonomic updates by the IOC.
Struggling to come up with your next birding destination or your next target bird? Want to find out the best time of year to look for a certain species?
Using past records as a guide is often the best way to make more productive birding journeys, so the team at the Singapore Birds Project has been working on what we hope will be a useful resource to help inform our readers.
Introducing the new, improved Rarities List page, in which we document locally rare species – now with added tables and bar charts which summarize past records. For an example, see the image below.
Clicking the bar chart icon brings up the species chart for Northern Boobook – most records are in early November but a sizable number occur in the spring too… so keep an eye out in the weeks ahead! Clicking on each bar brings up a summary of all the records during that time of the year, and you can click on those rows in the table to view more details on each sighting.
You can also click the table icon next to the species name to show all the records of that species in a tabular format.
Our database now contains over 1400 records and counting – and all this wouldn’t be possible without your support. Thank you, and keep those submissions coming!
Happy Lunar New Year to all those celebrating, and here’s to more megas in the Year of the Tiger!
[UPDATE 10/2/2022] The computational technique used to place individual records in different weeks was modified slightly and the screenshot above was replaced with the newer format.
If you need help with identification, don’t hesitate to ask on our Facebook group where many regionally experienced birdwatchers are present
To find out more about our philosophy and objectives of this database, check out this write-up
Basic questions but who has the answers?
A Digital Museum. Quite a catchy name, isn’t it? Now that we have grabbed your attention, here are some simple questions that we want to ask you: How many times has the Fairy Pitta been recorded in Singapore? The answer is twice. Easy, right! It’s been all over the news recently. Okay then, what about Chinese Blue Flycatcher? Hmm, there were some recent records but it’s difficult to be certain of the total count. Two? Three? The answer is four. Well, what about the Northern Boobook? Now that’s a tough one. Does anyone have this information at their fingertips…? A rather basic piece of information, it seems—just how many times a species has been seen. Yet no one appears to have the answer.
From left: Fairy Pitta Pitta nympha, Chinese Blue Flycatcher Cyornis glaucicomans, and Northern Boobook Ninox japonica. Photos by Dillen Ng and Sin Yong Chee Keita.
To find out more, let’s check what Singapore Birds Project has to say about the Northern Boobook.
Local Status: Uncommon migrant
Location: Records from Tuas South, Pasir Ris Park, and Satay by the Bay but could conceivably occur in any place with trees.
This gives us some rough ideas about the species. It certainly is not a common bird, so maybe less than 20 records in total? Still we’d like to know more details. After all, it is still a highly sought after species—knowing where and when to look for it provides clues on the best way to find an individual.
Searching eBird is not particularly effective either. There are a large number of data points with some being repeats of the same sighting, and it would be too time consuming to click through every point on the map.
Map of Northern Boobook sightings on eBird
Finding the answer to this seemingly simple question is actually rather difficult. One would first need to make an excel spreadsheet, click through every eBird data point, then collapse possibly duplicated sightings…and that’s not all. To obtain pre-eBird era information, there would also be a need to flip through old literature to tabulate all records.
This used to be the convoluted journey that any curious birdwatcher had to take to learn about most species, but that will no longer be the case.
Introducing the Singapore Birds Database
Using our newly launched Singapore Birds Database, you can get your answer in just a few clicks. All you need to do is to search for a species name, and voila! We can see that there are at least 16 confirmed local records of the Northern Boobook. How easy is that?!
The Singapore Birds Database contains local records of over 160 species of rare birds. Not only are details on the dates, location and species name of sightings included, we also provide links to primary sources (if available online) such as Facebook or scientific publications so that anybody can verify the data for themselves. For cases where there are records of a rarity at the same (or nearby) location after a period of absence, if we think that multiple records refer to the same individual, we provide internal links so that users can cross-reference the records.
A search of Northern Boobook in the Singapore Birds Database
How the Singapore Birds Database was conceptualised
In 2019/2020, we had a tremendous migration season with vagrants such as a Fairy Pitta, Daurian Redstarts, and Taiga Flycatchers showing up. It was quite extraordinary and we worked to publish about its peculiarity together with Singapore’s eBird reviewer, Martin Kennewell. Researching for our paper was very challenging because basic information about a species in Singapore (e.g. how many times has it been seen) was not readily available.
We thought to ourselves, why not create a database to address this problem? In January 2020, we decided to embark on a massive projectto compile all records of significant bird species in Singapore. And let’s not just compile it for personal use. Let’s make it public. Let’s make it comprehensive. Let’s make it easy to use. Let’s make sure that it is regularly updated. Let’s make it free to use. And most importantly, let’s make it transparent. We aim for this database to provide records, substantiated with primary evidence, such that users can also question and independently arrive at answers themselves.
We reviewed over 1000 records manually by checking through every available primary source, visiting libraries countless times, and trawling through the web like crazy. After 1.5 years of effort, we are finally ready to launch this database via the Singapore Birds Project website. For those who are keen, you can find out more about the processes and philosophy of our work in this write-up.
How can you be a part of our project?
If you encounter any rare species, please submit your sighting at this link to play a part in documenting Singapore’s avifauna. We also strongly encourage you to make use of eBird for your day-to-day birding adventures.
Please let us know if you notice any errors! We will do our best to update the database as soon as possible and with proper acknowledgements.
Lastly, if you have any ideas for our database or the Singapore Birds Project, feel free to contact us!
Moving forward
All records submitted to our database will be reviewed by the Singapore Birds Project Record Committee. One key focus behind our integrated user submission system and database is transparency, because we believe in making all records and decisions publicly accessible. Given that sightings are shared across a variety of online platforms nowadays, we will continue to actively look out for records of rarities to prevent data from slipping through the cracks, while encouraging user submissions. We aim to cover all bases by being vigilant and using a future ready approach.
The birdwatching community in Singapore has been growing rapidly and everyone is yearning to learn more about our feathered friends. The Singapore Birds Project has filled in the niche for being a reliable source of updated and accurate bird information. This new database is a big step forward in our aim to contribute to the local community. We aim to update our database with more information and explore various avenues to utilise this data. We hope to continue doing our work, not alone, but as a community together with all of you.
Acknowledgements
Raghav Narayanswamy and Francis Yap: A massive thank you to the two of you for creating the digital platform to present our database in such an elegant manner. If not for your efforts, our work would have been constrained to a single excel spreadsheet.
Adrian Silas Tay, Goh Cheng Teng, Lester Tan, Martin Kennewell, Richard White, and See Toh Yew Wai: The feedback all of you provided when testing the initial stages of our database helped improve our public interface tremendously.
Elize Ng, Geraldine Lee, Movin Nyanasengeran, Sandra Chia, Tan Hui Zhen, Twang Fang Qi: Your reviews helped to greatly refine our overarching document that explains the processes behind our work. Thanks for your time in reading through 18 pages of texts. We will probably continue sending you all our future blog posts, so be prepared :p
Martin Kennewell: We are constantly blown away by how you take on the herculean task of curating Singapore’s eBird data with such precision. Your efforts over the past few years in promoting the use of this platform locally is finally paying dividends. Thank you so much for your work!
Bird Ecology Study Group, Lee Kong Chian Natural History Museum, Nature Society (Singapore) Bird Group, Oriental Bird Club: Efforts and publications by these organisations have served as key documentation for numerous historical records, to which we are grateful for.
The past and present administrators of key Facebook groups (Bird Sightings, Birder’s Group, Singapore Birders): Curating content on Facebook is not easy [I know, because I’ve recently become one of them! – Keita] and the efforts have allowed us to search for important information when compiling modern records. Thank you for your effort.
Every single person who has contributed to advancing the local ornithology scene over the past two centuries: Thank you, if not for the efforts of everybody who documented and shared their records, we would be living in a very different community today.
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.
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
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
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
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
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 Conservation, 16, 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
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
Crimson-winged Woodpecker at Johor. Photo credit: Keita Sin
Velvet-fronted Nuthatch at Johor. Photo credit: Keita Sin
Masked Lapwing at Marina East Drive. Photo credit: Francis Yap
Milky Stork at Sungei Buloh Wetland Reserve. Photo credit: Francis Yap
Painted Stork at Thailand. Photo credit: Keita Sin
Pied Kingfisher at Sri Lanka. Photo Credit: Dillen Ng
Golden-backed Weaver at Lorong Halus Wetland. Photo credit: Francis Yap
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.
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.