26 May 2019

Festival of Biodiversity 2019!

Festival of Biodiversity 2019!
HDB Hub @ Toa Payoh : 25-26 May 2018

The 8th run of the Festival of Biodiversity (FOB) for 2019 was held over the 25-26 May weekend this year. In keeping with its objective of bringing biodiversity awareness, education and conservation to the masses and unconverted, this year's FOB was also held at an urban location - this time at the Housing and Development Board Hub in Toa Payoh. Moving from a southern mall (VivoCity) to central (Nex Mall), then to the eastern part of Singapore (Tampines Mall), FOB2019 is back at a central location.

An overview of the venue of the FOB 2019 at HDB Hub @ Toa Payoh

Background of FOB - An annual event organised by the National Parks Board (NParks) Singapore, in collaboration with the Biodiversity Roundtable, the Festival aims to create awareness and foster a sense of appreciation for Singapore's natural heritage. The festival showcases Singapore’s impressive and unique array of island biodiversity - both terrestrial and marine. This event celebrates Singapore’s natural heritage and in doing so, hopes to bring about greater awareness of the rich biodiversity that Singapore has.

The VVIPs, Minister Desmond Lee, President Halimah Yacob and CEO/NParks, Kenneth Er with winning photographers

This year's Guest of Honour at the FOB was the President of the Republic of Singapore, Mdm Halimah Yacob. Minister Desmond Lee hosted the FOB for six of the eight festivals, as he shared during his opening speech. He is often seen as the "Minister for Biodiversity" by the nature and environmental community in Singapore. Minister is a keen supporter of the nature conservation efforts of the community and is very knowledgeable on biodiversity matters.

Our host of FOB2019, Minister Desmond Lee, delivering his speech

Minister Desmond Lee's speech outlined two key areas that Singapore needed to work on, in the area of biodiversity conservation. He shared that "Looking ahead, we need to work on two areas, in order to protect our biodiversity to co-exist with this urban and busy city of ours at the same time. First, we need to ensure that the passion for discovery and nature stewardship reaches the broader community. Only with our community’s buy in and support can our conservation efforts succeed. Second, we will continue to improve our data gathering and analysis with the help of technology."

Various nature groups and NParks' sub-groups set up a total of around 20 booths at this year's FOB. Although the venue for FOB2019 was not as generous in terms of space compared to last year's event at Tampines Mall, the compact space was nonetheless just adequate for the showcasing of Singapore's rich biodiversity.

There were about 20 booths featuring Singapores rich biodiversity, and school kids briefing President Halimah Yacob about their project work.

On Day 1 of FOB2019, the visitorship from the weekend mall shoppers and nature enthusiasts appeared to be pretty good, and the corridors around the booths were packed with visitors who were curious about our local biodiversity. The various groups, NGOs and NParks' staff were on hand to explain about their respective areas of focus on Singapore's biodiversity.

This year, ButterflyCircle did not set up a booth at the FOB, as we decided to continue with being a visitor rather than a participant, until we are able to find more enthusiastic volunteers to man the two-day 12-hour sessions for the FOB. Perhaps another year in future...

FOB 2019 also launched the Gardens Bulletin Vol 71 (Supplement 1) 2019. This was the culmination of a two-year comprehensive survey of the Bukit Timah Nature Reserve. Many different groups covered various taxonomic categories and the surveys varied from transect to site surveys depending on the focus of the groups. For butterflies, we used several prescribed transects that were also used by other groups, whereby data could be analysed across the different groups to see if there are areas of correlation.

Excerpts of some pages of the survey paper for BTNR in the Gardens Bulletin Vol 71

Our paper entitled "Butterflies of the Bukit Timah Nature Reserve, Singapore, and its vicinity", is featured on pages 273-292 of this supplementary edition of the Gardens Bulletin Vol 71. In total, 13 field surveys were conducted, at the prescribed five transects and also the surrounding buffer parks of Dairy Farm Nature Park to the east of BTNR, Singapore Quarry to the west of BTNR and Hindhede Park to the south of BTNR from the period Jan 2016 to Dec 2017.

A total of 63 species were recorded only from the five transects in BTNR, whilst an overall higher number of 85 species were observed at the buffer parks. Of these, 49 species were found in both the BTNR transects and the buffer parks. In total, 112 species were recorded over the 13 field surveys.

Our conclusions show that, whilst the forested area within BTNR is a good base for the existence of many forest-dependent species, sightings of butterflies were relatively low due to the lack of food sources for the species. The buffer parks therefore provide an ideal source of nectaring plants and other food sources which the butterflies can come out to feed on.

The Bright Oakblue, a new addition to the Singapore Butterfly Checklist after the life history was completed

In the article, we also featured several species that were noteworthy of special mention. Amongst these were the newly added species to the Singapore checklist - the Bright Oakblue (Arhopala sublustris ridleyi). Whilst there are certainly more species of the cryptic lookalike genus to be recorded, forested areas such as BTNR is certainly a good location to look out for these Arhopalas.

A sample of some butterfly (and one caterpillar) species recorded during the BTNR survey

Other species observed during the surveys and mentioned in our paper included the Blue Helen, Malay Tailed Judy, Banded Royal, Fulvous Pied Flat and the Giant Redeye. The Fulvous Pied Flat was one species that was recorded as a new species to Singapore when it was observed at BTNR some years ago. During the survey, the elusive and rare Giant Redeye's caterpillar was observed, feeding on presumably a Nibong Palm (Oncosperma horridum).

Back to the FOB, it was a good gathering of old friends and catching up on the latest news. It was very encouraging to see the younger generation of Singaporeans stepping up for the biodiversity conservation cause and sharing their passion and effort in their respective areas of focus. Looking ahead to 2020, we hope that there are landlords of malls in the western side of Singapore who will come forward to host next year's FOB for a weekend as part of their CSR thrust to help in Singapore's biodiversity conservation initiatives.

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

Special thanks to ButterflyCircle members Chng CK, Foo JL, Huang CJ, Loke PF, Simon Sng, Horace Tan and the late Sunny Chir for their assistance in the photography and survey outings for the BTNR survey paper

Past Festivals of Biodiversity :

FOB 2012 at Singapore Botanic Gardens
FOB 2013 at VivoCity Mall
FOB 2014 at VivoCity Mall
FOB 2015 at VivoCity Mall
FOB 2016 at Singapore Botanic Gardens
FOB 2017 at NEX Mall, Serangoon Central
FOB 2018 at Tampines Mall

18 May 2019

Awls of Singapore : Part 2

Awls of Singapore : Part 2
Featuring the Awl skippers in Singapore

A Plain Banded Awl puddles on a terracotta tile floor

In Part 2 of the Awls of Singapore, we take a look at the remaining four species of skippers bearing the name "Awl" in their English Common names. As mentioned in Part 1 last week, the use of an everyday object (at least in the past) for the name of a butterfly is uncommon. The awl is, after all, a tool with a pointed tip used to make holes in leather or thick fabrics.

A White Banded Awl puddling at a concrete table

We now feature the four remaining species of the extant Awls found in Singapore - all of which belong to the genus Hasora. These are robust-bodied skippers that prefer the shaded forested areas and are usually more active in the early morning and late dusk hours of the day. They can also be found feeding on flowering plants or puddling on bird droppings and damp forest logs, footpaths and brick walls of buildings within the forested areas.

4) The Common Banded Awl (Hasora chromus chromus)

The Common Banded Awl is a relatively rare species but is widely distributed across Singapore, from the nature reserves to urban parks and gardens. It is a rapid flyer and more active in the early hours of the morning, where it zips across heavily shaded habitats, sometimes on tree trunks, feeding on the moisture of the morning dew. It can sometimes be found puddling on bird droppings, or feeding on flowers of trees like the Spicate Eugenia (Eugenia zeylanicum).

Typical behaviour of the Awls - hiding under a leaf

The upperside of the Common Banded Awl is dark brown in the male and unmarked, whilst the female has two crescentic spots on the forewings. On the underside, the base colour is a dull purple-brown with the white discal band usually narrow and outwardly diffused. The underside of the basal area of both wings is washed with a dull purple-blue sheen under certain lighting conditions. Forewing typically without an apical spot in space 6 of the forewing in the male, but in the female, there may be apical spots in spaces 6 and 7 on the forewing. The hindwing marginal white line extends indistinctly to the apex. The caterpillars have been successfully bred in Singapore on Pongamia pinnata.

5) The Plain Banded Awl (Hasora vitta vitta)

A Plain Banded Awl perched on a coconut tree trunk

The Plain Banded Awl appears very similar to the Common Banded Awl, and identification is often difficult in the field. It shares the same habits as its other cousins in that, when disturbed, it hides under a leaf with its wings folded upright. She species has been spotted at urban parks as well as in shady forested areas. A swift flyer, the Plain Banded Awl also displays crepuscular habits and regularly observed feeding at flowering trees and puddling.

Plain Banded Awls feeding on flowering plants

The Plain Banded Awl is dark brown above with a single prominent pale yellow sub-apical spot on the forewing of the male, whilst the female has additional large hyaline spots on the forewing. The underside is pale brown with the inner half of the hindwing having a bluish-grey glaze. The white post-discal band is usually broader than the Common Banded Awl. The hindwing marginal white line starts at the tornal area and generally ends at vein 3. The caterpillars have been successfully bred in Singapore on Spatholobus ferrugineus.

6) The White Banded Awl (Hasora taminatus malayana)

Like its other relatives, the White Banded Awl is mainly found in shady forested areas in the nature reserves. It also displays the habit of hiding under a leaf with its wings folded upright. Once disturbed it takes off at high speed to search for another hiding place. It is also found puddling on damp footpaths and walls of buildings in the vicinity of the nature reserves.

The male White Banded Awl is dark brown above and unmarked, whilst the female has small pale yellow post-discal spots on the forewing. The underside is pale brown with the wing bases strongly suffused with a bluish-green sheen. The white post-discal band is always narrow. The caterpillars of the White Banded Awl have been successfully bred on Derris trifoliata.

7) The Yellow Banded Awl (Hasora schoenherr chuza)

Yellow Banded Awl hiding under leaf (top) and puddling at a clay brick wall (bottom)

The Yellow Banded Awl is considered rare and usually encountered singly in the forested nature reserves of Singapore. It has the same habit of the other Hasoras of flying rapidly and then settling on the underside of a leaf to hide. It is often observed to puddle on bird droppings and other animal excretions and also fond of damp walls and tree trunks.

The Yellow Banded Awl is dark brown above with four sub-apical pale yellow spots, together with hyaline spots to form a confluent band. The hindwing has a broad yellow discal band. The underside is similarly marked but with lighter wing bases. In certain side lights, the apical and marginal areas on the underside of the wings may appear deep purple. The caterpillars of this species have been bred on Spatholobus ridleyi and Kunstleria ridleyi.

Text by Khew SK : Photos by Khew SK, Loke PF, Nelson Ong and Horace Tan.

12 May 2019

Awls of Singapore : Part 1

Awls of Singapore : Part 1
Featuring the Awl skippers in Singapore

A Orange Tailed Awl puddles on a damp timber plank

This weekend's blogpost takes a look at the various butterfly species that carry the English common name "Awl". The name Awl usually refers to a group of Hesperiidae (Skippers) that are medium-sized, robust-bodied butterflies classified under the sub-family Coeliadinae. In Singapore, the Awls come from three main genera - Badamia, Bibasis and Hasora.

A Common Awl perches in its typical under leaf pose

I did a word search to investigate the background of the name "Awl" and to look for the possible theories as to why this name was chosen for these butterflies. Invariably, the majority of online dictionaries define awl as a "A small pointed tool used for piercing holes, especially in leather." It is therefore interesting to consider why a butterfly is associated with a pointed tool for its common name!

This is what an "awl" is - a sharp tool to pierce holes in leather

Firstly, is it perhaps the broad bodies of the butterflies and sharply pointed wingtips that gave the early authors the idea that these species are reminiscent of the pointed tool? Or did these authors originally intending to name these butterflies after the bird "Owl" instead? There could always be a possibility that this name was misspelt as Awl? The group of butterflies are known to be crepuscular (active in the dim light in the dawn or dusk hours of the day), and hence could have been associated with nocturnal owls instead?

A Brown Awl extends its long proboscis to feed

It is not common to come across butterflies named after inanimate objects as its common name. In many of my discussions on the English or vernacular common names of butterflies, they are named after birds, animals, colour, people, behaviour, ranks, etc., but names after objects are few and far in between. We will never know for sure, the reasons why the early authors referred to these species as "Awls", but it can always be an interesting subject for debate!

This two-part blog article takes a look at the seven extant species of Awls in Singapore, with Part 1 showcasing three of the seven species. Amongst the butterflies called Awls, five are under the genus Hasora, and one each from the genus Badamia and Bibasis.

1) Brown Awl (Badamia exclamationis)

A Brown Awl feeding on the flower of the String Bush

The first of the Awls is a single genus-single species representative butterfly in Singapore. Globally, there are only two known species in the genus - the other being Badamia atrox, that flies in the islands of New Caledonia and Fiji. The Brown Awl has a large geographical range, starting from India at its western-most range, stretching all the way to Japan in the north-east and Australia in the south-east extremity of its range. In Singapore, the Brown Awl appears intermittently throughout the year, and can be found in the nature reserves as well as urban parks and gardens.

The Brown Awl is regularly observed hiding upside down on the undersides of leaves

The Brown Awl is a medium brown on the upperside, with elongate white hyaline streaks on the forewing in the female. These streaks are near-obscure in males of the species. The wing bases are greyish-green on the upperside. The underside is a drab greyish-brown and unmarked. The abdomen of the butterfly is striped brown and yellow. The wing shape of the Brown Awl is uniquely elongated with the hindwing strongly caudate, giving it a silhouette of a stealth bomber.

The Brown Awl is moderately rare and is usually encountered singly. It has a habit of hiding under leaves with its wings folded upright. It is skittish and a fast flyer. The species has been successfully bred on two caterpillar host plants in Singapore - Combretum sundaicum and Terminalia calamansanai.

2) The Orange Tailed Awl (Bibasis sena uniformis)

An Orange Tailed Awl puddling at a sandy streambank

The Orange Tailed Awl is rare, and a new discovery for Singapore when it was first observed in the forested nature reserves of Singapore. Subsequently, the caterpillars of the species were found in numbers in the Singapore Botanic Gardens on Hiptage benghalensis. However, the adult butterflies are still rarely seen, perhaps due to its crepuscular habits.

The Orange Tailed Awl is dark brown on its uppersides and unmarked. The wings are long and angular with the hindwing tornal cilia a deep orange yellow in pristine individuals. The underside has a broad white discal band on both wings and a purple-blue sheen. The hairs on the legs of the butterfly are orange yellow.

3) The Common Awl (Hasora badra badra)

A Common Awl perches on the underside of a palm frond

The Common Awl is a relatively widespread species in Singapore, and has been observed in urban parks and gardens as well as the forested nature reserves. It is one of five species in the genus Hasora. It is also closely associated with the mangrove and back-mangrove environments where its caterpillar host plant, Derris elliptica, grows wild as a creeper. It tends to prefer shaded habitats and has a habit of flying rapidly and then settling with its wings folded upright on the underside of a leaf to hide itself.

The Common Awl is often encountered puddling at footpaths, bird droppings, damp tree trunks and in the case of the last photo, even on damp brick walls!

The male Common Awl is dark brown above with the wings usually unmarked, although in some individuals, small sub-apical spots may be present. The female has three large pale yellowish sub-apical spots and large hyaline spots in the cell area of the forewing. The underside is brown with a light purplish glaze with a prominent circular white spot in the cell of the hindwing. When photographed with a flash, the purple glaze is enhanced, bringing out a strong purple blue sheen that is not usually seen in natural light.

In the next part of the Awls of Singapore, we take a look at the remaining four Awls that are extant in Singapore, all of which belong to the genus Hasora.

Text by Khew SK : Photos by David Chan, Khew SK, Koh CH, Michael Soh, Jonathan Soong and Horace Tan