Tag Archives: Albert Low

Migratory Bird Collisions in Singapore

The Black Bittern was exhausted. He had covered hundreds of kilometres during the night. Now the Sun was rising and it was time to find a suitable place to take a breather and find some food. However, everywhere he looked he saw the brightly lit outlines of concrete giants as far as the eye could see. Just then, he saw it. The first rays of sunlight had revealed a giant covered in greenery and, best of all, the unmistakable shimmering outline of a pond in the centre. The bittern changed course and made a beeline for the pond. Breakfast beckoned…

Singapore lies along a major migratory path along the East Asian-Australian Migratory Flyway (EAAF), undoubtedly Asia’s most important migratory flyway. Used by hundreds of millions of migratory birds annually, more than 100 migratory species pass Singapore on their migratory journeys to destinations further south, the most conspicuous being the shorebirds that can be easily observed in our wetland reserves. Less well known to the public are the songbirds, and other migratory landbirds like cuckoos, nightjars and kingfishers. Many of these species migrate at night, and while their journeys are fairly well documented in Europe and North America, species that migrate in eastern Asia remain very poorly known.

The phenomenon of migratory bird collisions is well-studied in North America, where estimates of birds killed range into the high hundreds of millions per annum, with the majority of these collisions occurring in heavily urbanised areas like New York City. According to scientists, these migratory collisions occur for two reasons. Firstly, many migratory birds migrating at night rely on stellar patterns in the sky for navigation, and thus may be misled by artificial lighting from man-made structures, drawing them in and leading to collisions. Secondly, birds are unable to distinguish reflections from real trees and greenery. As a result, birds flying through urban areas that have vegetation may be drawn to the reflections from windows. Either way, avian victims of these collisions are often too severely injured to proceed with their migrations, or otherwise perish.

Although the issue of bird collisions is unfamiliar to many Singaporeans, there have been an increasing number of reports from birdwatchers who were finding dead or injured migratory birds in urban areas beginning from the 1990s. To understand the extent of migratory bird collisions in Singapore, the Bird Group started a long-term (5 year) survey to document these collisions better. Our study aimed to 1) identify bird species that are prone to these collisions, 2) identify the geographical distribution of these collisions, 3) determine which time of the year these collisions are most frequent and 4) identify aspects of the urban landscape that may increase the risks of these collisions.

Our interview form was disseminated widely to the nature community in Singapore through Facebook and other channels. This form was designed to record key details on bird collisions records from the public, and is available online at http://www.tinyurl.com/sgbirdcrash. As the NUS avian genetics lab also receives many birds killed in such collisions, we are also collaborating with David Tan of the lab to compile details of these records.

This report summarises the results of the first year of data collection, which was carried out between September 2014 and April 2015. Migratory birds begin to arrive on our shores in numbers from September, and the vast majority will have left by April, so this period was chosen as collisions were most likely to occur within this timeframe.

A total of 47 incidents involving 18 species were documented between September 2014 and April 2015 (Table 1), of which 33 resulted in fatalities. Pittas (Pittidae) and flycatchers (Muscicapidae) were the most commonly reported victims, with 11 incidents involving two species of pitta and 10 incidents involving four species of flycatcher including the globally threatened Brown-chested Flycatcher (Rhinomyias brunneatus). Kingfishers (Alcedinidae) were also well represented with eight incidents, all of which involved the Oriental Dwarf Kingfisher (Ceyx erithacus). The remaining 18 incidents involved a wide range of families ranging from raptors (Accipitridae) to grasshopper warblers (Locustellidae) although no more than 5 incidents were documented for each of the families involved.

Bird collisions were most frequent during the fall, or autumn migration period between October and November compared to any other period during the migratory season for 2014/15 (Figure 1).

Figure1
Figure 1: Number of reported migratory bird collisions sorted by month during the 2014/15 migratory season.

The central and western parts of Singapore were found to be hotspots for migratory bird collisions (Figure 2). Of 47 reported collisions, 20 were from the central region, which is characterised by Singapore’s central business district and several residential districts near the southern boundary of the Central Catchment Nature Reserve. A further 13 incidents were reported from the west, which is characterised by heavy industrial land use but also includes a large tract of relatively undisturbed secondary forest at the Western Catchment military training area. These two regions combined accounted for 70% of all reported collisions during the study period.

The preliminary findings from our ongoing study indicate that in Singapore, the bird families most adversely affected by building collisions are pittas (Pittidae), flycatchers (Muscicapidae) and kingfishers (Alcedinidae). These three avian families are predominantly nocturnal migrants, with many nocturnal collisions and captures reported in other parts of the Malay Peninsula (Wells 2007). Consequently, these birds may be especially vulnerable to collisions with lighted structures owing to the multitude of high-rise, intensely lit housing and office blocks which are a feature of Singapore’s skyline and represent a deadly attraction to these birds.

Figure2
Figure 2: Migratory bird collisions classified by region based on boundaries demarcated on URA’s OneMap.

Our results also indicate that mortality resulting from building collisions was noticeably higher during the fall migration period compared to any other time during the migratory season. This finding was consistent with a recent study in North America (Loss et al. 2014), which suggested that this was due to larger populations of avian migrants in the fall due to the presence of first-time migrants which fledged during the preceding breeding season.

In summary, the preliminary results of this study demonstrate that bird-building collisions are a regular occurrence in Singapore, particularly during the fall migration period between October and November. Certain groups of birds, in particular pittas, flycatchers and kingfishers, appear to be particularly prone to such incidents. Collision incidents are also particularly prevalent along the central and western regions of Singapore.

We also encourage readers to report any bird crash victims they encounter via the online survey form found at the aforementioned address. Your contributions are invaluable in giving us greater insight into the dynamics of migratory bird collisions in Singapore and also assist in the formulation of management actions to mitigate these incidents.

Literature Cited
Loss, S.R., Will, T., Loss, S.S. and Marra, P.P. (2014). Bird-building collisions in the United States: Estimates of annual mortality and species vulnerability. The Condor 116: 8 – 23.
Wells, D.R. (2007). Birds of the Thai-Malay Peninsula. Volume 2. London, UK: Academic Press.

Table 1: The 18 species of avian migrants involved in bird-window collisions between September 2014 and April 2015. Migration period refers to the months of October to November as well as March and April where many birds are passing through Singapore, while wintering period refers to the months between December to February where collisions most likely involve birds which are wintering in Singapore.
Table1

Crashed Bird Gallery


 Downloadable Report (Microsoft Word): Link

  
Principal Author: Albert Low
Photo Credit: Lim Kim Chuah

Destination Singapore: A Birder’s Gateway to the Jungles of Southeast Asia – Part 3

Singapore lies on the East Asian-Australasian Flyway (EAAF), a migratory route used by the greatest diversity of migratory birds on the planet. Each year, hundreds of millions of birds of more than 400 species set off from as far away as Arctic Siberia to spend the winter in the tropical climate of Southeast Asia. In Singapore, many people tend to associate migratory birds with the flocks of shorebirds that visit Sungei Buloh Wetland Reserve every year from September to April. However, there are also many other species that either pass through Singapore en route to destinations further south or choose to spend their winter here. In this instalment, we profile three migratory birds which can be very difficult to see either in their breeding range or elsewhere in Southeast Asia during the migration period.

Swinhoe's Storm PetrelFirst up, we have the avian equivalent of the seafarers who made Singapore’s ports and associated shipping lanes famous. The Swinhoe’s Storm-Petrel breeds on inaccessible islands off the coast of Korea, eastern Russia and Japan and makes the annual journey to winter in the Indian Ocean. As part of the process, these birds also utilise the Singapore Straits as the quickest means to get from the Pacific Ocean to their wintering grounds. Every year during the months of September and May, chartering a boat out into the Singapore Straits can yield hundreds of these birds moving East to West (September) and vice versa (May) as they make the arduous journey between the two oceans. Flocks of tired birds can even be seen resting on the water, against the backdrop of some of the busiest shipping lanes in the world. Interestingly, this bird is surprisingly difficult to see anywhere outside Singapore, and even serious Japanese birdwatchers have visited Singapore specifically looking for this species despite living relatively close to their breeding habitats further north.

Von Schrenck's BitternNext, we feature a secretive visitor to our well-wooded freshwater streams and ponds during the migratory season. The Von Schrenk’s Bittern breeds in the wetlands of East Asia and winters throughout Southeast Asia as far south as Sulawesi. Unlike its cousins, who inhabit open freshwater wetlands and marshes, this species appears to favour well-wooded freshwater habitats where it is usually solitary and extremely retiring. This species is apparently not uncommon in Singapore during the passage period, evident from the multiple records of dead individuals that collide with glass buildings while on migration every year. However, seeing them in the wild is a completely different matter, as they are often well camouflaged in the streamside vegetation of our forest streams and ponds. Nevertheless, in recent years it has become apparent that some individuals spend a comparatively long time around easily accessed sites, as recent sightings of a male at Lower Peirce Boardwalk and a female at Sungei Buloh Wetland Reserve demonstrate. Both these individuals were present for at least a month, providing observers with a rare opportunity to document the ecology and foraging behaviour of this little-known species. Outside of Singapore, they appear to be only rarely encountered, with one of the few regular sites being Happy Island in China during spring migration when the species passes by on their journey to Heilongjiang or Amurland.

Yellow-rumped FlycatcherLastly, we feature a handsome songbird which transits in Singapore on its way to its wintering grounds in the Indonesian islands of Sumatra and Java. The Korean or Yellow-rumped Flycatcher is a sexually dimorphic species with males sporting a particularly attractive black and yellow plumage. Females are comparatively duller but can still be identified by their distinctive yellow rump. Every year in October, large numbers spend anywhere from several days to a fortnight in Singapore refuelling before making the final leg of their journey south. During this period, it is not unusual to find some trees in our forests and parks festooned with dozens of these birds, particularly after a sustained period of bad weather. Interestingly, significantly more females than males are observed in Singapore, the reasons for which are still poorly understood. Recent banding studies show that large numbers of these birds pass through small islands in the Gulf of Thailand on their way north in spring, but the species is otherwise unobtrusive and infrequently observed. One way to locate these birds is through their characteristic chattery-trill, which we have managed to obtain recordings of (xeno-canto Link). During the short aforementioned period, however, this species is locally common in Singapore and can be encountered anywhere from urban parks to our nature reserves.

Singapore, like many countries along the EAAF, is a hotspot for migratory birds between October to April every year. Beyond the flocks of waders that captivate visitors to our coasts, more than 100 species of migratory birds occur unobtrusively in our parks and green spaces, often right under the noses of visitors. The featured species are but the tip of the iceberg, and readers are encouraged to learn more about and appreciate the epic annual journeys made by many of these species, some of which are no bigger than the palm of your hand!

Photo Gallery of the birds featured:

Part 1 of the series
Part 2 of the series

This article is written and edited by our guest contributor Albert Low with help from Yong Ding Li. They are both highly travelled birdwatchers from Singapore, and are among the top Asian birders, ranked by number of bird species seen in Asia. Photo Credits: Francis Yap

Destination Singapore: A Birder’s Gateway to the Jungles of Southeast Asia – Part 2

When asked about Singapore’s birdlife, many locals bemoan the perceived lack of colour displayed by the birds they encounter in their daily life. While mynas, sunbirds and orioles may not be on the same level as the rainbow-coloured denizens of Asia’s rainforests, Singapore does have its fair share of colourful birds, some of which are also difficult to observe elsewhere in Asia. In this instalment, we profile three colourful avian residents which dwell unobtrusively in our midst, many of whom can be observed even in our urban parks and green spaces.

copper-throated sunbird-zacc We start with one of the more specialised sunbirds in the region – the mangrove-dwelling Copper-throated Sunbird. In poor light, males of this species can appear almost uniformly black, but when seen well, the iridescent quality of its plumage comes into its own, with a kaleidoscope of colours that even modern cameras struggle to document. This large sunbird has a patchy distribution throughout Southeast Asia, confined primarily to large tracts of good quality mangroves in southern Thailand and the Malay Peninsula as well as the Greater Sundas and Palawan. In Singapore, the species has persisted where most of our other mangrove specialists have faded away, and is regularly seen, some would say even locally common, in our remaining mangrove forests. The readily accessible Sungei Buloh Wetland Reserve, one of the local strongholds of this species, is one of the few places in the World where one could expect an encounter within minutes of stepping out of a taxi.

 

red-legged crake-zacc
(Red-legged Crake by ZaccHD)

Our next representative is a widespread resident throughout our island, but its crepuscular habits and strange vocalisations have confounded numerous observers over the years. Meet the Red-legged Crake. This forest-dwelling rail is widespread throughout Southeast Asia. However, its tendency to scurry mouse-like away from danger, coupled with being most active at dawn and dusk, means that few observers see anything more than a fleeting glimpse in the field. In Singapore, however, this species has adapted to inhabiting a wide range of wooded habitats throughout the island. Arguably the best place to see this species in the World is at our world-renowned Singapore Botanical Gardens, where individuals and even parents with young chicks frequently forage by the sides of footpaths and on open lawns in broad daylight, seemingly unperturbed by the multitude of park users and tourists. When viewed up close, it is an extremely attractive species, sporting a crimson-red iris and legs, rich chestnut brown plumage and Zebra-esque barring on its belly.

Long-tailed ParakeetFinally, we can’t have an article on colourful birds without a representative from the parrot family! Of the three species of parakeet found in Singapore, the Long-tailed Parakeet is the only native representative, and also has the distinction of being a globally near-threatened species. Males of this species are an eyeful with their bright red bills, peach coloured cheeks, black “beard” and long flowing tails. Unlike the other introduced parakeets, this species prefers the forest edge and adjacent areas of suitable habitat. In Singapore, despite competition from the introduced Red-breasted Parakeet, it is still readily observed on the edge of our nature reserves and larger tracts of woodland, while recent studies have shown that it also roosts communally in urban areas throughout the country. This is in marked contrast to the rest of Southeast Asia, where the species is generally only uncommonly recorded, and usually flying high above forested areas or along the coast.

While the spectacular birds of Southeast Asia’s rainforests tend to grab all the headlines, Singapore’s colourful avian residents are equally sought after by well-travelled global birdwatchers. Now that you, the reader, are familiar with some of our local avian jewels, look out for them on your daily commute or during your leisure time, they could well brighten up your day as well!

Photo Gallery of the birds featured:

Part 1 of the series
Part 3 of the series

This article is written and edited by our guest contributor Albert Low with help from Yong Ding Li. They are both highly travelled birdwatchers from Singapore, and are among the top Asian birders, ranked by number of bird species seen in Asia. Photo Credits: ZaccHD, Francis Yap.

China to Sumatra via Singapore: The Journey of the Brown-chested Jungle Flycatcher

To many casual birdwatchers, the Brown-chested Jungle Flycatcher (Rhinomyias brunneata) is just another of the many hundreds of ‘brown jobs’ that dwell in the region. The more serious birders and conservationists however, know it to be globally threatened, and appreciate its rarity in the region.

Brown-chested Jungle Flycatcher
(A Brown-chested Jungle Flycatcher from Bidadari, Singapore. Photographed in September 2012)

In Singapore, veterans of the Singapore Bird Race remember it as a ‘species in bold’, in the race checklist, a classification reserved for many of our rarest birds, and thus in need of special documentation in the race. First discovered in northern Singapore back in the early 1980s, the Brown-chested Jungle Flycatcher was a bird one seldom saw, and there were only a handful of records every year. In recent years, much has been learnt about the ecology of this little songbird. Birdwatchers visiting the famous Bidadari Cemetery found small numbers of these birds every October since 2006, and in 2013, a total of eight birds were sighted in the little patch of woodland of no more than 15 hectares in size. Parallel surveys I conducted in the Central Catchment Forest found as many as six birds in one morning in mid-October, or an average of 1 bird for every kilometre walked. Birdwatchers around the world now acknowledge that Singapore is probably the best place to see the Brown-chested Jungle Flycatcher in the world during the fall migration period between October-November, much more so that at it’s breeding habitat in China.

So, why the apparent rarity? One reason is that the Brown-chested Jungle Flycatcher has a habit of skulking in dense patches of undergrowth in woodlands and forests, perching motionless on a low twig while watching the ground for the unfortunate bug. Many birdwatchers are thus likely to have walked past the flycatcher without realising that it is there, just metres away in the bushes. Secondly, the drab-brownish colour tones of the Brown-chested Jungle Flycatcher mean that to the uninitiated, it can be quite a challenge to tell it apart from other flycatchers, many of which are also brownish and show subtle differences which are difficult to pick out when seen poorly. Thirdly, not many people know the calls the Brown-chested Jungle-Flycatcher makes. Only in recent years do we now know it produces a harsh series of ‘ticks’, a call made when it is alarmed, or when another Jungle Flycatcher comes too close into its territory. (Link to my recording on Xeno-canto Link1, Link2). This call is so similar to that made by Blue Flycatchers of the genus Cyornis, that it is not surprising why some taxonomists now consider it part of that group.

Brown-chested Jungle Flycatcher
(A Brown-chested Jungle Flycatcher from Bidadari, Singapore. Photographed on a low twig.)

In Singapore, the Brown-chested Jungle Flycatcher occurs as a passage migrant, which means that birds seen here are on their way to their wintering destination elsewhere. Breeding in the mountainous broadleaved forests of southern and central China (e.g. Hunan, Guangdong, Jiangxi, Fujian, Guizhou), Brown-chested Jungle Flycatchers head south from August onwards, briefly passing through northern Vietnam. By mid-September, they would have reached Central Thailand, as confirmed by regular sightings around Bangkok . Sightings from Singapore are mainly from the last few days of September to early November and there are very few records of birds staying through winter. Birds have also been collected from the One Fathom Bank Lighthouse in the Straits of Malacca in November before the 1920s, while hundreds were mist-netted on migration in Frasers Hill in the 1960s.

For many years, no one knew for sure where they spend their winters. A major clue came when a team in Java mist-netted a Brown-chested Jungle Flycatcher in the Gunung Halimun National Park southwest of Jakarta. Subsequently, photographers based in Sumatra obtained images of ‘unknown flycatchers’ which were subsequently re-identified as the Brown-chested Jungle Flycatchers. Part of the confusion stemmed from the fact that the bird was not listed for Sumatra in the main bird field guide (i.e. Mackinnon et al’s Birds of Sumatra, Borneo, Java and Bali) covering the region. We now know that the bird has been found in the Bukit Barisan Selatan National Park in Lampung, and the Harapan Rainforest in Jambi province. In short, we now know that the humble Brown-chested Jungle Flycatcher makes a journey of 3,500km each way in Autumn and Spring, a massive distance for such a small little bird.

Photo Gallery

Reference:
MacKinnon, J., & Phillipps, K. (1993). A field guide to the birds of Borneo, Sumatra, Java, and Bali: the Greater Sunda Islands. Oxford, UK: Oxford University Press.

This post is written by our contributor Yong Ding Li with additional input from Albert Low. Photographs by Francis Yap.

Destination Singapore: A Birder’s Gateway to the Jungles of Southeast Asia – Part 1

Every year, the varied habitats of Southeast Asia draw scores of international birdwatchers to the region in search of its avian jewels. Over a fifth of the world’s birds occurs in this region, from pittas and trogons in the lush rainforests of Indonesia to rare wintering waders on the coasts of Thailand, and any aspiring global birdwatcher is likely to require several visits to the region to do it justice to Southeast Asia’s incredible birdlife.

The island nation of Singapore, with its world-renowned airport and excellent infrastructure, is widely regarded as the gateway to Southeast Asia. However, what many birders don’t realise is that apart from being a transit hub to exotic destinations around the region, Singapore is in itself an excellent birding destination, home to a both resident and migratory birds which are often very tricky to observe in other countries in the region. Trying to see some of these species in other parts of tropical Asia would often involve visits to remote national parks and which would require lengthy journeys over rugged terrain. In this instalment, we profile three globally threatened and near-threatened resident bird species which are commonly encountered in Singapore, but otherwise difficult to observe elsewhere.

Straw-headed Bulbul Con Foley We start the ball rolling with the globally threatened Straw-headed Bulbul, one of the largest and most distinctive bulbuls in Southeast Asia and unfortunately, also perhaps the most threatened. This bulbul was once common throughout much of Southeast Asia, but its beautiful song has made it highly sought after in the cage bird trade. Consequently populations have crashed throughout the region, particularly in Indonesia and Thailand.

The bulbul inhabits secondary forests along the interface between water and land, and can be found in a range of habitats from riverine forests to mangroves. In Singapore, the Straw-headed Bulbul has also adapted well to wooded public parks and is readily encountered in suitable habitat across the island. Thankfully, many local sites supporting good numbers of this species are also well-used recreational spaces that are regularly patrolled by rangers, which appear to deter would-be poachers from trapping these iconic birds. Some of the best places to observe this magnificent songster is the Bukit Batok Nature Park, and the island of Pulau Ubin.

Another regular avian feature of Singapore’s wooded landscape is the globally Near-threatened Grey-headed Fish-Eagle. This distinctive raptor generally inhabits forested rivers and lakes and although widespread throughout Southeast Asia and the Indian Subcontinent, is locally distributed and in decline due to habitat loss and pollution across many of the region’s large rivers.
OLYMPUS DIGITAL CAMERA
Grey-headed Fish-eagle at Guilin Nature Park. Photo Alan OwYong

However, just as with the aforementioned species, this bird appears to have adapted to urban water bodies in Singapore, and the ample supply of large non-native fish introduced by irresponsible pet owners inhabiting them. Interestingly, this species is now regularly encountered at many urban green spaces throughout Singapore including the Singapore Botanic Gardens and breeds regularly on the hills around Little Guilin Park. The continuing expansion of this eagle into urban Singapore offers a unique case study into how introduced species have the potential to benefit the very predators which consume them.

Last but not least, we have the globally Near-threatened Chestnut-bellied Malkoha, Singapore’s only surviving member of this distinctive group. Despite being a member of the cuckoo family, malkohas do not lay their eggs in the nests of other birds but instead construct nests and raise their own chicks. Many malkohas inhabit the rainforests of Southeast Asia and are consequently threatened by habitat loss, and this species is no exception. Outside of Singapore, this species is infrequently encountered in mangroves, rainforest and secondary growth throughout Peninsular Malaysia, Sumatra and Borneo.

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Chestnut-bellied Malkoha at Mandai Orchid Gardens Photo: Alan OwYong.

In Singapore, however, the species is not regularly encountered in mangroves but instead is fairly common in our forest reserves and adjacent areas of secondary growth and even well-wooded parks. Many international birders visiting Singapore include this in their lists of must-see birds during their sojourn on the island.

So the next time you visit Singapore on a birding trip, take some time to explore the country as well! You just might end up adding some lifers to your list which you otherwise might not have seen. For the local birdwatchers, do take the time to appreciate our feathered friends who share the island with us; there is more to Singapore’s birds than just crows and mynas!

This article is written and edited by our guest contributors Albert Low and Yong Ding Li. They are both highly travelled birdwatchers from Singapore, and are among the top Asian birders, ranked by number of bird species seen in Asia. Photo Credits: Con Foley, Alan OwYong & Francis Yap.

 

Photo Gallery of the birds featured:

Part 2 of the series
Part 3 of the series

This article is written and edited by our guest contributor Albert Low with help from Yong Ding Li. They are both highly travelled birdwatchers from Singapore, and are among the top Asian birders, ranked by number of bird species seen in Asia. Photo Credits: Con Foley, Alan OwYong & Francis Yap.