29 December 2019

2019 - Looking Back

ButterflyCircle 2019 - Looking Back...
The Year in Review

A Blue Helen (Papilio prexaspes prexaspes) puddling

We are now into the final two days of this decade that started 10 years ago in 2010. In less than 48 hours, we will be stepping into a new year, 2020 and an exciting decade ahead. The world is changing rapidly, and we have seen unprecedented occurrences taking place all around us. Climate change events continue to alarm many countries around the world with stronger typhoons, heavier rains, hotter summers and so on.

Singapore has started preparing for imminent rising sea levels and this is a very long term strategy that our island state can no longer postpone. It is a matter of when it happens, not if, - and certainly something that we can only take care of ourselves rather than wait for help from anyone else. But even as we take the environment seriously, on another side of the coin is the decision to take a calculated risk and putting a mass-rapid tunnel below the 'green heart' of the island, the Central Catchment Nature Reserve.

ButterflyCircle members on an outing at Pulau Ubin - Jan 2019

ButterflyCircle members on field surveys

We take a look back at the year 2019, and muse about the butterfly scene that we were part of, over the past 12 months. What have we contributed to furthering of awareness and conservation of butterflies on our island, and sharing information and knowledge to fellow enthusiasts around the world? Have we done enough? What else can we do?

The year started with a blogpost on some special butterflies on Pulau Ubin, a rustic offshore island of Singapore. We featured 10 species that were spotted on this little 1,020 Hectare island - some of them first observed on Ubin and/or thus far only found on Ubin. This island continues to attract interesting species of butterflies time and again. Nature enthusiasts are determined to see the island remain as a nature sanctuary and conserved for as long as possible. A group, Friends of Ubin Network has been set up to collaborate with government organisations to suggest how the charm and activities on Ubin can be preserved.

Then we investigated two species that were discovered or re-discovered in Singapore - the Angled Castor and the Malayan Jester. Initially, a single individual of these species was spotted - the Angled Castor in a patch of forest in the Mandai area, and the Malayan Jester at an open area near the Herb Garden at Nanyang Technological University.

Subsequently, colonies of both species that sustained a few months of presence were discovered the Angled Castor on Pulau Ubin, and the Malayan Jester at Dairy Farm Nature Park. The critical success factors that led to these species' longer term survival in Singapore are interesting to document as a conservation initiative and to see if they are replicable to sustain the existence of these species for an even longer term.

The long-running Butterfly of the Month series continued into its twelfth year, with a feature butterfly each month and showcasing the species with more photos and discussed in more detail. As at Dec 2019, this blog has now showcased 146 species as its monthly centrefold butterfly, collecting photo contributions from members of ButterflyCircle and sharing their excellent work via these monthly articles.

Three additional parts of our feature blogposts on Assorted Nectaring Plants that butterflies visit for their sustenance were added to our repository of articles. These featured flowering plants that are cultivated in parks and gardens, as well as wildflowers (sometimes referred to as "weeds") that are attractive to butterflies and are important to the survival of butterflies in our environment. Take a walk down 2019's memory lane and savour the photos of these flowering plants in Part 2, Part 3 and Part 4 of our series. This brings the total flowering plant species that butterflies feed on, to 40 plants on this blog's archives.

Some sample shots of the collective groups of butterflies by their common English names

We continued our series of articles on the collective groups of butterflies known by their English common names. In 2019, we showcased the Albatrosses, Archdukes, Awls, Bobs, Yeomen, Demons Royals, Barons and Imperials found in Singapore. Known by their easier-to-remember common names, these articles compared the individual species in these groups of butterflies, some of which are very similar in appearance and diagnostic features elaborated to help ID them in the field. There was also an additional article featuring butterfly species that are named after flowers, making them "flying flowers" as we have come to know these beautiful creatures.

A blogpost on butterflies' legs

Eyespots on butterflies' wings.  Decorations or funtional?

Two anatomical articles were added to our series on the morphological and physical features of butterflies. This year, we discussed the butterfly's legs, their function in helping butterflies in their daily activities, the variation of legs across the families, colours, lengths and appendages that are found on the butterflies' legs. A second article discussed the presence of ocelli or eyespots on butterflies' wings and their possible use in mimicry and protection from predators.

Another blogpost, along the same thrust of discussing morphological features of the wings of a butterfly, took a closer look at camouflage - this time via mimicking leaf patterns and shapes. Although the highlight species featured in the article Leafy Disguises no longer exists in Singapore, another slightly less accomplished mimic of leaves, the Autumn Leaf, is still extant.

As part of citizen science contributions, ButterflyCircle members continued our participation in various surveys, particularly for the Comprehensive Ubin Butterfly Surveys (CUBS) and for the Wildlife Reserves of Singapore (WRS) for Pulau Ubin and Mandai area respectively. Our earlier Bukit Timah Nature Reserve surveys culminated in a paper that was included in the Gardens Bulletin that was launched at the Festival of Biodiversity 2019.

This year, we featured one of our butterfly photography locations in the northern part of Singapore. The Sg Buloh Wetland Reserve, which is a more well-known nature park for migratory bird watching, is also unique for some butterfly species preferring the mangrove habitats.

Another blogpost discussed the use of buffer parks as a conservation strategy to help to reduce visitorship pressure on the nature reserves by providing interesting alternative venues for the public to enjoy nature-related activities. The development of these nature parks is part of a holistic approach to strengthen the conservation of the biodiversity in Singapore’s nature reserves.

We celebrated Singapore's 54th National Day in Aug 2019 by featuring red-and-white butterflies of Singapore - the national colours of Singapore's Flag. In another blogpost, showcasing the monochrome butterflies, we highlighted some simple and inconspicuous black-and-white butterfly species that call Singapore their home.

Some ButterflyCircle members went on three overseas trips to neighbouring countries to check out the butterflies there. The butterfly travelogues featured the trips to Mahua, Sabah in East Malaysia and Ipoh in West Malaysia. We also did another of our "pilgrimage" trips to meet our good Italian friend Antonio in Thailand, again visiting Chiangmai and Chiangdao for our annual butterfly "fix".

Two butterfly books were also featured, sharing these excellent work by their respective authors on the butterflies of their countries. The first, Butterflies of Australia by Dr Albert Orr and Prof Roger Kitching, is unique in that all the illustrations of butterflies in the book are hand-drawn. The second book is a recent acquisition for me - the Butterflies of South Africa by Steve Woodhall. This is another book that is a must-have for visiting butterfly enthusiasts to South Africa. A 2nd edition is in the works and will be launched next year.

We took a look at butterfly species whose caterpillars feed on various species of bamboos in the two-part article on Bamboo Feeders. Bamboos are important host plants for a wide variety of butterflies and should continue to be cultivated and conserved in our environment. Then we had a blogpost on adult butterflies that are attracted to overripe fruits in the blogpost Fruit Feeders.

A discussion on a simple citizen science suggestion on relative abundance indicators was the subject of another blogpost. We discussed the use of simple terminology to describe the relative "rarity" of the status of butterflies instead of the more scientifically rigorous IUCN definitions. This was more to simplify understanding for the layman enthusiast rather than replace any scientific nomenclature.

We then ended the year's blogposts by showcasing some occasional visitors to Singapore. Bringing the number of blogposts to 958 with Occasional Visitors since I started this blog back in 2007, we ended the year on a positive note that butterflies, unlike us humans, respect no boundaries nor political divides. They fly far and free and we hope that more will visit our little island in the sun in the coming decade.

Chinese New Year Teacup of 2019, the fifth in the series, featuring the Orange Emigrant by Loh Mei Yee

And there we have it, a busy 2019, and I would like to wish all our readers a Happy 2020 and a successful and peaceful year ahead for all. And to a great year ahead for butterflying and to our butterflies, live long and prosper!

Text by Khew SK : Photos by Bob Cheong, Chng CK, Foo JL, Federick Ho, Huang CJ, Khew SK, Loh MY, Jonathan Soong, Horace Tan and Anthony Wong,

21 December 2019

Occasional Visitors

Occasional Visitors
Strays and Vagrants to Singapore

A Vagrant puddling with open wings

During the Northeast monsoon season in the region, the prevailing winds herald the wet season in Southeast Asia. The predominantly north-easterly winds blow from the South China sea towards Singapore bringing heavy rains and the occasional flash floods. The eastern coasts of West Malaysia and South Thailand are usually inundated with heavy rains during this period too.

The yellow arrows show the prevailing NE monsoon winds blowing from Malaysia towards Singapore

With the winds blowing from southern Johor towards Singapore, there have been observations in the past years that certain butterfly species that are not resident in Singapore suddenly appear during these months. Also, it is possible that some species are blown southwards in Singapore and somehow stay a little longer (if they are able to breed with available host plants).

This weekend's blogpost investigates some of these "strays or vagrants" that are typically not seen in Singapore. However, seasonally, they may appear for a short period of time, and then disappear as suddenly and may not be seen for several years thereafter. The list is not exhaustive and is just a sample of the "exotic" species that stray into Singapore from time to time.

1) The Wanderer (Pareronia valeria lutescens)

The Wanderer belongs to the Pieridae family, of which several species are known to participate in migratory behaviour. This species, in particular, the male, is a strong flyer and can likely bridge the sea gap between Johor and Singapore. With a little aid from the winds blowing in the right direction, it can likely reach the northern coasts of Singapore. The Wanderer has been spotted on the northern offshore island of Pulau Ubin. After several unconfirmed sightings, a lone female was successfully photographed in Feb 2011.

The males continued to be spotted from time to time, but taking a photo of the skittish and fast-flying male is easier said than done. The male Wanderer is pale blue above, with prominent black veins on both wings. In the female, the wings bases are yellowish with broadly black-dusted veins. When in flight, the upperside of the female closely resembles the Yellow Glassy Tiger. The underside is paler and the colours muted, almost resembling a weathered individual of a Yellow Glassy Tiger. The flight of the female closely mimics that of the distasteful Danaid, as compared to the speedy flight of the male Wanderer.

2) The Yellow Glassy Tiger (Parantica aspasia aspasia)

This slow-flying Danainae has been spotted many times all across Singapore - from Pulau Ubin in the north, to Gardens by the Bay in the south. It was also observed in the urban parks along the Southern Ridges. The species was once extant in Singapore, but is no longer considered a resident species of Singapore. It makes an appearance once in a while and is by no means as commonly seen as in Malaysia.

The Yellow Glassy Tiger, as earlier mentioned in this blogpost, is the model for the mimetic female Wanderer. Its wings are predominantly bluish-grey with narrow black longitudinal streaks. Each wing has a bright yellow basal patch of which the hindwing has a more extensive yellow area. Whilst it exhibits Batesian mimicry with the female Wanderer, it is also a classic example of Mullerian mimicry where the day-flying moth, Cyclosia pieridoides also mimics the Yellow Glassy Tiger for mutual protection via aposematic colouration.

3) The Orange Gull (Cephora iudith malaya)

Another Pieridae species, the Orange Gull was a very recent re-discovery on Pulau Ubin in Dec 2018. Reinforcing the theory that some of these Malaysian species appear in Singapore during the NE Monsoon months, the Orange Gull is one example. Again, with Pulau Ubin as the nearest pitstop to mainland Malaysia, it is likely that this is a wind-assisted stray that appeared in Singapore. Listed as extant in Singapore by the early authors, this species has not been reliably recorded for many decades until one year ago.

An Orange Gull spotted recently on Pulau Ubin in Singapore

The underside of the hindwing of the Orange Gull is yellow with the tornal area dark orange and brown marginal borders. On the upperside the wings are predominantly white with black veins but the tornal half of the hindwing is a bright yellow. The species is often observed puddling at sand banks with other butterflies. Like many of its related species in the family Pieridae, it is a strong flyer.

4) The Vagrant (Vagrans sinha sinha)

The Vagrant was another re-discovery when it was spotted by chance at Gardens by the Bay in June 2013. Though documented as a Singapore-extant species by the early authors, the Vagrant has not been seen on the island for several decades. It was then photographed again one year later, in June 2014 at the Seletar Golf Course Butterfly garden, and then again last year in Sep 2018 at a reservoir park. Whether there is a viable colony surviving on the island or not, remains to be seen.

The Vagrant is coloured a rich fulvous orange on the uppersides, with dark brown borders, spots and patches on both wings. The underside is paler, with light greenish scaling at the tornal area of the hindwing. It is skittish and swift in flight and can sometimes be found puddling. It has a characteristic half-open wing pose when foraging on the ground.

5) The Danaid Eggfly (Hypolimnas missippus missippus)

The Danaid Eggfly is one of three species of the genus Hypolimnas that are found in Singapore. One of the other species, Hypolimnas bolina, has two different subspecies flying here in Singapore. The Danaid Eggfly was recorded as extant in Singapore. However it is again, very rare and only a handful of sightings of the species have been made in Singapore. The majority of observations have been at the urban hill parks at the Southern Ridges.

The male of the Danaid Eggfly closely resembles the Great Eggfly and Jacintha Eggfly, whilst the female (which has not been photographed in Singapore yet), is a good mimic of the Plain Tiger (Danaus chrysippus chrysippus). On the underside the white hindwing patch is much larger than the related species, and there is a distinct costal marking on the hindwing that is a diagnostic characteristic of this species.

And there we have, 5 examples of strays or vagrants to the Singapore butterfly scene. It is likely that more will be seen in the coming years, as butterflies do not respect geographical or political borders and fly freely between adjacent countries.

Text by Khew SK : Photos by Khew SK, Koh CH, Loke PF, Bobby Mun, Nelson Ong and Michael Soh