25 August 2018

Sailors of Singapore

Sailors of Singapore
Featuring the Sailor butterflies of Singapore

Short Banded Sailor feeding on Ixora flowers

Amongst the black-and-white striped butterflies of the sub-family Limetidinidae, we showcased the Sergeant (or Athyma species) in an earlier blog article. This weekend, we take a look at another group of butterflies featuring a similar striped look. Of these species, 3 are from the genus Neptis and one from the genus Phaedyma that have a 'zebra-striped' appearance. Collectively referred to as "Sailors", currently only 4 of these Sailor butterflies are extant in Singapore.

Common Sailor feeding on ripened fruit of Singapore Rhododendron

These Sailors (also referred to as Sailers in some references), fly more gracefully than their cousins, the Sergeants (that, by the way, also "sail" as they fly, albeit more rapidly). These Sailors tend to use the typical flap-glide-flap flight characteristic. They are, however, rather skittish and have a wide circle of fear that makes them hard to approach, unless they are distracted when feeding.

Burmese Sailor feeding on ripened fruit of Singapore Rhododendron

Of the sailors found here in Singapore, three are black-and-white striped and the last one is dark brown-light brown striped and quite dissimilar to any other species found in Singapore. The sole brown-coloured sailor is also the least common of the four, preferring the forested habitats in the nature reserves.

Short-Banded Sailor (Phaedyma columella singa)

The first of the four Sailors to be featured is placed in a different genus from the other three species of Sailors. It is the only representative of its genus Phaedyma in the region. This black-and-white Sailor is considered common in Singapore, and is widely distributed, from the forested areas to urban Singapore in parks and gardens.

Sporting its graceful gliding flight, the Short Banded Sailor can often be observed flying at treetop level, stopping to sunbathe with its wings opened flat amongst the foliage amongst roadside shrubs and trees. It is skittish, and when alert, is hard to approach.

With its characteristic striped appearance, it resembles the other two related Neptis species. The characteristic features that separate the Short-Banded Sailor from the two Neptis species are :

  • The triangular discal patch on the forewing is rounded and not elongated.
  • The post-discal white spot in space 2 at the dorsum of the forewing is usually missing, but where it occurs, much smaller than the spot in space 1.
  • Underside is deep orange-brown and the hindwing discal band does not reach the costa.
  • Underside of hindwing, the white discal band not prominently outlined in black.
The Common Sailor (Neptis hylas papaja)

The Common Sailor is the first of three species of the Neptis genus that is extant in Singapore. It is relatively widespread in distribution, and can be found in urban parks and gardens as well at the fringes of the nature reserves. It is moderately common and can usually be observed flying singly amongst shrubbery, and resting with its wings opened flat.

The upperside is black-and-white striped, with the discal stripe on the forewing with a subtle "break". The underside is a rich golden brown and on the underside, the white discal band is prominently outlined by black lines.

The diagnostic features of the Common Sailor to look out for, to distinguish it from the other two lookalikes black-and-white striped Sailors are :
  • The triangular discal patch on the forewing is usually more elongated and sharper than that of the Short Banded Sailor.
  • The post-discal white spot in space 2 at the dorsal edge of the forewing is always present and much larger than the spot in space 1.
  • Underside is rich golden brown and the hindwing white discal band reaches the costa.
  • Underside of hindwing, the white discal band is prominently outlined in black.
  • On the upperside, the abdomen is not white-ringed adjacent to the white discal band on the hindwing.
The Burmese Sailor (Neptis leucoporos cresina)

The Burmese Sailor (formerly called the Grey Sailor in the 1st edition of Butterflies of Singapore), is a predominantly forest-dependent species. It is relatively common in locations where its caterpillar host plant, Gironniera nervosa can be found. The species is rarely seen in urban areas.

The Burmese Sailor sports the same black-and-white striped appearance like many of the other Sailor butterflies. On the underside, the base colour is greyish brown and is quite unlike any of the other Sailor species in Singapore. The Burmese Sailor's flap-glide-flap flight is typical of the genus and it is usually quite skittish and not easy to approach without spooking it away.

The diagnostic features of the Burmese Sailor that distinguishes it from the Short-Banded and Common Sailor are as follows :
  • The triangular discal patch on the forewing is long and elongated, ending in a sharp point. The discal stripe is usually unbroken.
  • The post-discal white spot in space 2 at the dorsal edge of the forewing is always present and much larger than the spot in space 1.
  • Underside base colour is greyish to greyish-brown and the hindwing discal band, which is not outlined in black, does not reach the costa.
  • On the upperside, the abdomen is white ringed adjacent to the white discal band on the hindwing.
The Chocolate Sailor (Neptis harita harita)

The last of the Sailor butterflies found in Singapore is distinctly different from the other species in that the black-and-white stripes are replaced with dark and light brown. Despite the similar striped appearance, the brown stripes are obvious enough that this species is unlikely to be confused with any of the other Sailor species in Singapore.

The Chocolate Sailor (also called Dingiest Sailer in some books) is rare and is usually found in the forested areas within the nature reserves of Singapore. It was recorded as a new discovery for Singapore when it was first spotted in the early 1990's in the Mandai area. The butterfly is dark brown with lighter brown stripes across both wings. The distinctive crescent-shaped post-discal spot in space 3 of the forewing sets it apart from the other brown Sailor species that are found in Malaysia.

The diagnostic features of the Chocolate Sailor are :
  • Dark brown/light brown striped appearance, instead of the usual black-and-white stripes.
  • Post-discal spot at space 3 of the forewing is crescent shaped.
  • Underside is slightly paler, but also with a brownish base colour.
There is a total of 15 other Neptis species that can be found in Malaysia, and it is quite possible that one or two of these lookalike species may appear in Singapore in the future. With these basic identification tips on the four that are found here, do look out for any future discoveries that may appear on this little island one day!

Text by Khew SK : Photos by Goh EC, Federick Ho, Khew SK, Horace Tan, Bene Tay, Anthony Wong and Mark Wong

18 August 2018

Butterfly of the Month - August 2018

Butterfly of the Month - August 2018
The Banded Yeoman (Cirrochroa orissa orissa)

A Banded Yeoman puddling on the ground 

Just over a week ago, the Republic of Singapore celebrated its 53rd birthday on 9 Aug 2018 - 53 years of independence after it broke away from Malaysia in 1965. Back then, post-separation, Singapore was not expected to survive long on its own. A small island nation of only 580 sq km in 1965, it had no natural resources, a resident population of about 1.9m people, scant financial resources, virtually no army and a host of political and internal security issues to deal with.

A Banded Yeoman hides under a leaf with its wings folded upright

In just over five decades, the little country punched well above its weight, grew its economy and physical size - it has a land area of about 720 sq km today, physically expanding, through reclamation, by nearly 25% since 1965. Today, Singapore ranks amongst the top 10 countries in terms of Gross Domestic Product per capita according to the International Monetary Fund.

A Banded Yeoman sunbathes with its wings opened flat

Looking forward, stormy skies loom ahead. Singapore's past successes cannot be taken for granted, as the nation struggles with high cost of living, a more demanding and vocal citizenry and business competition from other emerging economies in the region. However, Singapore still has a number of things going for it, and it has to leverage on these pluses to leap ahead in the coming decades. This is where the government is focusing on, to re-invent Singapore and restructure the economy in the face of uncertain and rapid-changing global environment.

It is also in August that the Chinese Hungry Ghost month (7th month of the Lunar Calendar) starts. An annual Chinese tradition for the spirits of the afterlife, there are many do's and don't's that have been passed from generation to generation. The Hungry Ghost Month is, generally speaking, a bad time to do anything. Many significant milestones are avoided at this time, as people believe it's simply bad luck - from renovations, to moving house or buying an apartment, to getting married.

One of the interesting no-no's is "killing a moth" (or a butterfly for that matter). The Chinese believe that spirits are reincarnated as insects, especially moths. And the souls of the dear departed are in the moths (and butterflies) that visit your homes in the wee hours of the night. So stay away from killing any moths and butterflies during the month, lest it is the soul of a loved one visiting you!

A Banded Yeoman feeding on the flower of the Bandicoot Berry (Leea indica)

Our feature Butterfly of the Month for August 2018 is the Banded Yeoman (Cirrochroa orissa orissa). This is a moderately rare species in Singapore and is forest-dependent. It is rather local in distribution, and regularly sighted at its favourite sites in the Central Catchment Nature Reserves where its caterpillar host plant, Ryparosa scortechinii, grows.

The Banded Yeoman is ochreous brown on the upperside of its forewing, with a yellow post-discal band and a black apical border. The hindwing is also ochreous brown above with a series of marginal and sub-marginal lines and black spots that is typical of species of the genus Cirrochroa (collectively called the Yeoman butterflies).

The underside is much paler, and generally reflects the patterns and markings on the upperside. The broad apical area on the forewing has two white apical spots. The post-discal silvery band is a diagnostic feature to separate the species in the genus. In flight, the Banded Yeoman resembles another species that flies in Singapore - the Rustic. Indeed, both species are often seen together when feeding at flowering plants like the Bandicoot Berry (Leea indica) along forest paths.

The Banded Yeoman is skittish and is always on the move. It has a habit of flying and hiding on the underside of leaves with its wings folded upright. The species is relatively more common in Malaysia, often seen in secondary forests and nature parks, where several individuals can be observed together.

A Banded Yeoman puddling on a damp footpath

The species is also often observed to puddle at muddy footpaths near forest streams. Even when puddling, it has a habit of opening and closing its wings as it twists and turns whilst probing its proboscis in search of nutrients in the damp mud or sand.

A newly eclosed Banded Yeoman clinging on to its pupal case

The caterpillar has been successfully bred on the forest plant Ryparosa scortechinii in Singapore. The host plant is uncommon and is primarily found in the forested nature reserves of Singapore. At certain hours of the day, the Banded Yeoman can be observed to sunbathe on the tops of leaves and opening its wings flat to capture the heat of the sun.

Interestingly, this is the 888th article to be posted on this blog, as we feature our Butterfly of the Month today at exactly 18:08 on 18/08/18. That's a lot of auspicious 8's and will hopefully bring everyone lots of luck for the remaining months of this year!

Text by Khew SK : Photos by Antonio Giudici, Goh LC, Federick Ho, Khew SK, Loke PF, Tai LA, Tea Yi Kai, Horace Tan and Anthony Wong

11 August 2018

Book Review : Butterflies of Vietnam

Book Review : Common Butterflies of Vietnam
Dedicated books on Vietnam Butterflies

A recent business trip to Ho Chi Minh City (formerly Saigon) in South Vietnam led me to a local bookshop near the hotel where I stayed. Whilst browsing around the nature section, I wondered how many books I would find about the local butterfly fauna of Vietnam. The shop did not stock any, although there were quite a few other books about birds, flora and landscapes of Vietnam.

Of the 10 ASEAN countries, relatively comprehensive hardcopy literature on butterflies can be found for Malaysia, Thailand, Philippines, Laos and Singapore. The remaining ASEAN countries are Myanmar, Cambodia, Brunei Darussalam, Indonesia and Vietnam. There are basic guidebooks and many work-in-progress books for the majority of these countries. Amongst all the books available, Pisuth Ek-Amnuay's 944-page Butterflies of Thailand Vol 2 stands out as the largest comprehensive work on Thai butterflies.

A quick search online for books on the Butterflies of Vietnam showed that there are a couple of basic 'illustrated checklist and field guide' type of books, and a few more comprehensive work in progress. Most were authored by Dr Alexander Monastyrskii, a Russian entomologist, in collaboration with several other co-authors.

A basic Field Guide on the Common Butterflies of Vietnam, published in 2002 is touted as the "first illustrated field guide to the Butterflies of Vietnam". This 63-page field guide, featuring 105 of the common butterfly species in Vietnam, showcases hand-drawn illustrations of butterflies. These drawings by artist Wendy Gibbs, are very accurate drawings of the actual butterflies from a set collection.

The book opens with a foreword penned by Mr Nguyen Minh Thong, the IUCN Country representative, and Prof Vu Quang Con, the Director of the Institute of Ecology and Biological Resources in Hanoi.

Like the majority of butterfly books, the first six pages dwell with some basic information on classification, morphology, life cycle, behaviour, ecology and conservation. Having probably been worked on in the late 1990s and early 2000's the authors used the old taxonomic classification prior to the more recent consolidation of several families into Nymphalidae., this does not really detract from the value of this basic field guide in helping to identify common butterflies found in Vietnam.

The species pages are organised in a very simple format with the scientific names stopping at the species level. English common names are also given, and are generally quite consistent with many of the books available on ASEAN butterflies. For example the Neptis species are called "Sailors" in this book, as opposed to "Sailers" that are used by other authors.

Each species has a short write-up, describing the butterflies' behaviours, differences between the sexes, favourite nectaring plants and geographical range where the butterfly occurs. For some of the species, upper and underside or male/female illustrations are shown, using the half-butterfly depiction that is used in WA Fleming's Butterflies of West Malaysia and Singapore.

Given the small number of butterfly species featured - 105, which is less than 10% of the total number of species found in Vietnam, a reader will quickly look for more comprehensive books about Vietnam's butterflies. The good news is that there are several updates by the same author available. An example is the 114-page 2nd edition of the Butterflies of Vietnam: An Illustrated Checklist published in 2016.

Dr Monastyrskii also expanded his work into a work-in-progress series :
Butterflies of Vietnam, Volume 1: Nymphalidae: Satyrinae in 2005
Butterflies of Vietnam, Volume 2: Papilionidae in 2007
Butterflies of Vietnam, Volume 3: Nymphalidae: Danainae, Amathusiinae in 2012
These are more comprehensive books showing a wider collection of the species found in Vietnam and I am sure that more volumes will be available in due course.

For the more serious students, a scientific paper on The Biogeography of the Butterfly Fauna of Vietnam With a Focus on the Endemic Species (Lepidoptera), by A.L. Monastyrskii and J.D. Holloway, is also available. This paper discusses the biogeographic distribution of Vietnamese butterflies, featuring several key endemics found in Vietnam.

So for butterfly watchers who visit Vietnam, do check out these books for your reference to help you to identify what you have seen in various parts of this biodiversity-rich ASEAN country. Vietnam is a large country covering a total of 331,230.8 km2 of land mass and has a long coastal line. The current number of species recorded is 1,181 and counting.

Text by Khew SK

Photo plates from the books are copyrighted property of their respective authors and publishers, and samples of the pages from the books are featured here under the principles of fair use.