05 August 2018

Butterfly Survey @ Zoo

Butterfly Biodiversity Project
Butterfly Survey at Mandai Zoo


WRS Invertebrate team and ButterflyCircle members

The Singapore Zoo, previously known as the Singapore Zoological Gardens, but often referred to by locals as the Mandai Zoo, was first opened in mid 1973. Sitting on a site of about 28 Hectares, the Singapore Zoo was one of the first to feature "open zoo" exhibits in the region, where animals are displayed in natural habitats without the use of cages.



Over the years, the success of the Singapore Zoo, under the stewardship of Wildlife Reserves Singapore (WRS) continued. WRS also manages the popular Night Safari (the world's first nocturnal wildlife park), River Safari and the Jurong Bird Park.


The future Mandai Nature Precinct © Mandai Park Holdings

In 2015, Singapore investment company Temasek partnered the Singapore Government to spearhead the rejuvenation of Mandai into an integrated wildlife and nature heritage precinct in Singapore. Within the next decade or so, the Singapore Zoo, Night Safari and River Safari will be joined by two new cousins, the new Bird Park and the Rainforest Park, creating an integrated nature and wildlife experience for all visitors to Mandai.


A quick discussion before the survey commenced

This weekend, ButterflyCircle members were invited to assist the WRS Invertebrate Team to conduct baseline surveys on butterfly biodiversity at the Singapore Zoo. The WRS Team intends to enhance butterfly biodiversity through its Butterfly Biodiversity Project in the coming months. This project aims to improve the butterfly fauna in the Mandai precinct by planting host and nectaring plants for local butterflies within the parks.


Looking up for the butterflies!


Our morning survey started with a short briefing by Delvinder Kaur, the coordinator of the project, and explaining the survey methodology. When we commenced the survey just past 10am in the morning, the Saturday morning crowd had already begun streaming in. The transect-based survey took us on a trail starting near the white rhino exhibit and ending at the Fragile Forest aviary.



The overcast morning was not the most ideal weather for butterfly watching, but there were a few Lemon Emigrants, Grass Yellows and a lone Striped Albatross flying about. Delvin also explained that the trails that we were surveying were no longer fogged with pesticides and hence more butterfly-friendly.


At the Tropical Crops patch.  The waters of the Upper Seletar Reservoir can be seen on the left of the photo

Our walk brought us to the tropical crops area of the Zoo, which was just adjacent to the shores of Upper Seletar Reservoir Park. I recall this area from past visits to the Zoo, and where a trellis of Aristolochia acuminata, the host plant of the Common Birdwing and Common Rose, was cultivated. Both these species did not make an appearance this morning, though.


Pupa of the Autumn Leaf

We spotted a Leopard fluttering restlessly about, and a few more Lemon Emigrants trying to puddle at the freshly-tilled soil on the plant beds. I also noticed that the host plant of the subspecies pratipa of the Autumn Leaf still lined some of the trails around the area. We first spotted this subspecies, which is different in appearance from the subspecies bisaltide which is the more commonly observed subspecies all around Singapore, at the Zoo.



Caterpillar and adult female of the Autumn Leaf subspecies pratipa


Caterpillar and adult female of the Autumn Leaf subspecies bisaltide

The caterpillar of subspecies pratipa is distinctly different from the more common bisaltide in that the spots on its body are white, instead of orange. Photographic records of subspecies pratipa dated back to Aug 2007 when we were on a survey at the Zoo. This subspecies has not been seen in Singapore in recent years. Hopefully, the caterpillars will appear at the Zoo again.



The survey ended just near the new Reptopia exhibit, where we called it a day. We spotted a couple of Common Palmflies frolicking around the bushes. We took the opportunity to visit the Fragile Forest and the new butterfly aviary. This butterfly aviary was a recent add-on, but is facing some issues with predatory ants and a bunch of unwelcome moth caterpillars. The Clipper (Parthenos sylvia) and the orange form-chrysippus of the Plain Tiger were the two most common species flying in the aviary.



The new butterfly aviary adjacent to the Fragile Forest

A quick tour of the back-of-house, and visiting the breeding facilities that were still very much the same as I remembered from over 10 years ago, we ended our butterfly survey for the day. I also recall that back in 2011, the Zoo was helping to translocate the Metallic Caerulean (Jamides alecto ageladas) from the Mandai Orchid Garden that was being demolished. It would be good to check if this species can still be found at the Zoo.



A female Autumn Leaf subspecies pratipa ovipositing on its host plant at the Singapore Zoo

It was an interesting re-visit to the Zoo and we look forward to the forthcoming butterfly surveys in the months ahead. With a more targeted strategy of planting more host and nectaring plants for butterflies under the Butterfly Biodiversity Project, we hope to see a greater diversity of species at the Zoo in the near future.

Text by Khew SK : Photos by Huang CJ, Khew SK and Horace Tan

28 July 2018

Sergeants of Singapore

The Sergeants of Singapore
Featuring the 5 Athyma species in Singapore


A female form-neftina Colour Sergeant feeds on the ripened fruit of the Straits Rhododendron

The genus Athyma comprises of butterflies with rather robust bodies and are powerful fliers. They belong to the subfamily Limetidinae of the family Nymphalidae. The butterflies have a horizontal striped appearance, usually black and white in the males, and females in some species that have the white bands replaced with either orange or brown.


A Common Sergeant (Athyma perius perius) that is no longer found in Singapore today

The are currently five extant species of the Athyma species in Singapore - often referred to as "Sergeants" by their English common names. There was a sixth species recorded from Singapore by the early authors - Common Sergeant (Athyma perius perius), but this species has not been seen in the wild for almost five or more decades in Singapore, and no longer considered an extant species here.


A male Colour Sergeant (Athyma nefte subrata) perches on a leaf

The other five "Sergeant" species continued to be regularly observed in Singapore over the years, with some more common than others. They are medium-sized butterflies with wingspans averaging between 55mm to 65mm. This blog post features all the five species and compares their differences and diagnostic features to distinguish and identify them.

The Lance Sergeant (Athyma pravara helma)


A Lance Sergeant.  Note the cell streak on the forewing which is complete and unbroken

The Lance Sergeant is the most distinctive of these black-and-white Sergeants in Singapore. The cell streak on the forewing is unbroken and club-like and this sets it apart from all the other Athymas found in Singapore.



It was a recent new discovery to Singapore, recorded in the mid-1990's and added to the Singapore Checklist. It has made a regular appearance thereafter, usually spotted when feeding on the ripened fruits of the Straits/Singapore Rhododendron (Melastoma malabathricum) and at flowering Syzygium trees.



It can be occasionally observed puddling at damp muddy footpaths in the nature reserves. The full life history has been recorded on a species of Uncaria found in the forested nature reserves of Singapore. In terms of size, the Lance Sergeant is probably the smallest of the five Athymas found in Singapore.

The Colour Sergeant (Athyma nefte subrata)


A male Colour Sergeant sunbathing. Note the blue sheen on the white bands

The Colour Sergeant is the most often seen species amongst the Athymas in Singapore. It can be observed at urban parks and gardens as well as in the nature reserves. The males are black and white striped in the usual Sergeant look, but the white stripes appear bluish when viewed with angled lighting.


A female Colour Sergeant - form-subrata

A female Colour Sergeant - form-neftina

The females of this species occur in two forms - the orange-and-black form-neftina and the brown-and-black form-subrata. The orange female form is the commoner of the two forms. The undersides are usually paler in colour with a more washed-out appearance.




A female Colour Sergeant form-neftina feeding on the ripened fruit of the Straits Rhododendron

Males are fond of perching on the top surfaces of leaves with wings opened flat, and 'attacking' intruders that wander into its space. Both sexes are often found feeding greedily on the ripened fruits of the Straits/Singapore Rhododendron.

The Dot-Dash Sergeant (Athyma kanwa kanwa)



The strange English common name of this Sergeant probably came from its cell streak which ends in a triangular 'dot'. The species is largely forest-dependent and is not often found outside the sanctuary of the nature reserves in Singapore. It is rare, and usually spotted singly.


A Dot-Dash Sergeant sunbathing with its wings opened flat.  Note the narrow cell-end streak and the sharp and angular spot at the end of the streak

A powerful flyer like its other cousins in the group, it sports the flap-glide flight characteristic of the other Sergeants. It is skittish and alert, making it a challenge to photograph it, as any slight disturbance will spook it to speed away and up to the treetops.


A puddling Dot-Dash Sergeant

The Dot-Dash Sergeant has the usual black-and-white stripes on its wings. The cell streak on the forewing above is separated from the triangular spot (which is sharp and angular). The underside is a greyish-brown.

The Malay Staff Sergeant (Athyma reta moorei)


A Malay Staff Sergeant.  Note the twice-constricted cell streak on the forewing

The Malay Staff Sergeant is probably the rarest of the genus in Singapore, and is usually observed within the forested areas in the nature reserves. As with most of its other cousins, it is usually spotted singly, either sunbathing on the tops of leaves, or feeding at flowering plants.



The species is also known to puddle at damp muddy footpaths. The distinguishing markings of the Malay Staff Sergeant is the twice constricted white cell streak and the triangular spot is separated from this streak. The triangular spot is also more rounded compared to the Dot-Dash Sergeant's sharper and angular shape.

The Studded Sergeant (Athyma asura idita)


A puddling Studded Sergeant.  Note the black centred submarginal white spots on the hindwings

The Studded Sergeant is the largest member of the Athyma genus found in Singapore. It is also a forest-dependent species but is also regularly spotted in the vicinity of mangrove areas at Pulau Ubin and Sg Buloh Wetland Reserve.


A Studded Sergeant with wings folded upright.  Note the black-centred apical spots on the forewing

The cell streak is narrow and the cell-end spot is small and rounded. The unique feature of the Studded Sergeant is the black-centred white spots at the submarginal band of the hindwing. In the local subspecies, the spots are sometimes indistinct. The apical spots on the forewing are also black-centred.


The colourful caterpillar of the Studded Sergeant

The Studded Sergeant has been locally bred on two host plants - Ilex cymosa (Aquifoliaceae), and another unidentified Ilex species in the nature reserve. The caterpillar is attractive, with bright blue spots on a green body amidst sharp spines.


A Studded Sergeant feeding at the flowers of the Mile-a-Minute weed

And there you have it, the five "Sergeants" that you can spot in Singapore. And the next time you encounter one, you can hopefully be equipped to identify which of these Sergeants that you have spotted!

Text by Khew SK : Photos by Khew SK, Koh CH, Loke PF, Nelson Ong, Jonathan Soong, Horace Tan and Anthony Wong

21 July 2018

Butterfly of the Month - July 2018

Butterfly of the Month - July 2018
The Purple Bush Brown (Mycalesis orseis nautilus)



The month of July 2018 will probably be most remembered for the 2018 FIFA World Cup in Russia, a miraculous cavern rescue in Chiang Rai, Thailand, and the major cybersecurity breach of personal data in Singapore. We live in interesting times, and there are often outcomes that are still unpredictable, like who would win the World Cup, despite all means (including cats, birds and anything that can be believed!) of soothsaying by those who gambled away small fortunes.


A Purple Bush Brown found in southern Thailand - same subspecies as the one in Peninsular Malaysia and Singapore

So France won the 2018 World Cup. Along the way, the usually successful Latin American teams dropped like flies, and so did defending champions Germany. Asian teams didn't make it far into the games, with only Japan remaining in the last 16 before bowing out to Belgium despite leading 2-0. The next World Cup in 2022 will be held in Doha, Qatar, and the games shifted to the end of the year to avoid the 40+ degrees summer heat in the Middle Eastern nation.



Then over in the sleepy provincial town of Chiang Rai in northern Thailand, a group of 12 teenagers and their football coach decided to take an excursion into the cave complex at Tham Luang. As this is the monsoon season in northern Thailand, the torrential storms caused flash floods that cut off the group's exit as rain water flooded the passages. A search-and-rescue operation commenced and it was only after more than 10 days of searching that they were found on a ledge more than 3km into the cave complex.



The rescue operation that followed was described as nothing short of a miracle, as the personnel involved took great risks to bring a group of boys out through the treacherous labyrinth, many parts of which were totally submerged. All in all, it was a successful rescue operation with all the boys and their coach making it out with much difficulty. Sadly, there was one casualty, a Thai Navy SEAL diver who ran out of air whilst playing a crucial support role of bringing oxygen tanks and placing them along the route for the rescuers.



The Purple Bush Brown is often encountered flying low amongst the undergrowth, in deep forest shade, perching on the top of a leaf or blade of grass.  

Back home in Singapore, hackers infiltrated the government's health database and stole the confidential records of over 1.5 million patients, including the Prime Minister's drug prescriptions. Whilst the government had to soothe alarmed patients whose personal data had been compromised, the government's Cyber Security Agency will be busy patching up vulnerabilities and weaknesses in the IT system. In this cyber age and the era of connectivity, I cannot imagine having to go back to the paper and filing systems of the last millennium. Hence it is a risk that the government and any private company will have to face and resolve, moving forward.



We move back to our butterfly world with our feature butterfly of the month of July 2018. This month's butterfly is the Purple Bush Brown (Mycalesis orseis nautilus). The species is adorned with ocelli (or eye spots) on the margins of both wings and is one of many similar-looking species in the Mycalesis genus, often referred to as Bush Browns.



In Singapore, the Purple Bush Brown is the rarest species amongst the six species found here. However, the ocelli are distinctive and identification of the Purple Bush Brown is less challenging when compared to separating a few of its other close cousins. The Purple Bush Brown has prominent and distinct yellow-ringed ocelli that are rather uniform in size.



Individuals of this species have a full complement of ocelli on both wings with rather crisp colours and distinct outlines on the ocelli. The relatively uniform post-discal band is broad and faintly violet-washed in pristine individuals. There is a thin dark brown sub-basal line on both wings.



The butterfly is rather local in distribution and is considered rare in Singapore. It is a forest-dependent species and is not encountered beyond the sanctuary of heavily shaded forested areas in the nature reserves. It is usually observed singly, flying low amongst the undergrowth and grasses in heavy shade.



The Purple Bush Brown has also been observed to feed on overripe fallen fruits on the forest floor. The life history of this species has not been recorded yet in Singapore, although its caterpillars are likely to feed on a type of grass, like many of its other closely related species in the sub-family Satyrinae.

Text by Khew SK : Photos by Antonio Giudici, Federick Ho, Khew SK, Koh CH, Loke PF, Billy Oh, Tan CP and Benjamin Yam.