15 June 2019

Bobs of Singapore

The Bob Skippers of Singapore
Featuring Skippers with the English name Bob

This weekend's blogpost looks at a number of butterflies from the Hesperiidae family that have been given the English common name of "Bob". Common names of butterflies have always been intriguing in that it is hard to say for sure what were the thoughts of the early authors who coined these names for the butterflies.

Think of the name "Bob" and probably the first thing that comes to mind would be the name of a person. However, a quick search on the internet would give "Bob" a series of different meanings that can range from a hairstyle to a coin used in the UK to a short abrupt motion, amongst many other definitions. The English language is rather complex in this instance, where a single word carries many different meanings.

But the subject of this article focuses on our butterflies, and the several species that carry the name "Bob". Interestingly, the majority of species that I have come across that are called "Bob" are in the family Hesperiidae (or Skippers). It would be interesting to find out what the intent of the origins of the name "Bob" for these skippers. Was it because of the way they fly? Or perhaps their size? We will never know for sure. Nevertheless, in Singapore, we have 4 species of skippers with the name Bob.

1) Chestnut Bob (Iambrix salsala salsala)

The Chestnut Bob is a common butterfly that is quite widespread in distribution across Singapore. It is more often found in urban parks and gardens flying low but rapidly around open grassy patches, but can also be found at the fringes of nature parks amongst the low shrubbery. It often stops to sunbathe in the typical skipper pose with the hindwings opened flat whilst the forewings are held open at an angle.

The species is dark brown on its uppersides with a paler post-discal band in the male, and white spots in the female on the forewing. The underside is a reddish brown with a series of silvery-white spots on both wings. The butterfly is small, with a wingspan of about 25-30mm and flies rapidly. The caterpillar of this species feeds on the Common Cow Grass (Axonopus compressus) amongst other varieties of grasses.

2) Starry Bob (Iambrix stellifer)

The Starry Bob (or Malayan Chestnut Bob) superficially resembles the Chestnut Bob. It is, however, a forest-dependent species and is rarely found outside the forested nature reserves in Singapore. It flight and habits also mirrors its more common cousin. Within the nature reserves, it is regularly found feeding on the flowers of the Bandicoot Berry (Leea indica).

The upperside of the Starry Bob is dark brown and unmarked. On the underside, it appears reddish brown but has an orange-speckled appearance, particularly on the forewing apical area and the basal area of the hindwing. Like the Chestnut Bob, both wings feature a series of silvery-white spots except for the diagnostic white spot in space 5 of the hindwing, which is placed between the cell end and termen.

3) Palm Bob (Suastus gremius gremius)

The Palm Bob (or Indian Palm Bob) was recorded as a new discovery for Singapore when it was added to the checklist of butterflies in Singapore in the 1990's. Back then, reference books described the species as "very rare" and confined to only mangrove areas in northern Malaysia. Perhaps in those years, the species had just made its appearance from India through Thailand and was uncommon.

Today, the species is widespread and common in parks and gardens. A medium brown butterfly, there are a few large yellowish-white spots on the wings on the forewing above. The underside is a paler brown, and overlaid with buff scaling with a number of sharply defined discal black spots. The caterpillars of this species feeds on a variety of palms, a few of which are ornamental palms that are commonly used in urban landscaping.

4) White Palm Bob (Suastus everyx everyx)

Again another new discovery to Singapore when it was recorded, the White Palm Bob is rare and confined to the forested areas of our nature reserves. Being a small and insignificant species, usually spotted hiding amongst undergrowth in heavily shaded forests, the White Palm Bob may have been missed by the early authors. It is skittish and a fast-flyer, but often stops to rest with its wings folded upright. It has been observed to puddle at damp muddy areas and also on bird droppings.

The species is dark brown above and unmarked, except for a narrow whitened area at the tornus of the hindwing. The underside is a lighter brown and the hindwing is largely whitened. There are a few black spots on the hindwing of which there is one large submarginal spot at space 2 of the hindwing. The caterpillars of this species feeds on a type of thorny palm that is normally found in forested areas.

Text by Khew SK : Photos by Huang CJ, Khew SK, Koh CH, Loh MY, Jonathan Soong, Horace Tan, Anthony Wong and Benjamin Yam

This article is dedicated to one of ButterflyCircle's veteran member, "Uncle" Bob Cheong, who is taking a break from butterfly photography due to a personal domestic issue. We hope that Bob will return soon to our beloved butterflies and share his awesome photos that have been a source of enjoyment for many of his fans.

09 June 2019

Buffer Parks to Nature Reserves

Buffer Parks to Nature Reserves
An Effective Means of Conserving Biodiversity?

A mating pair of Common Posy shot at Dairy Farm Nature Park

Recently, the Gardens Bulletin Vol 71 (Supplement 1) was launched. This special issue features the Comprehensive Biodiversity Survey of Bukit Timah Nature Reserve - a survey that spanned over two years. The section on butterflies, titled "Butterflies of the Bukit Timah Nature Reserve, Singapore, and its vicinity" covered five transects featuring various habitats. In my discussion, I made reference to the usefulness of green buffer parks to BTNR and how these buffer parks play an important role in sustaining butterfly populations through judicious planting of nectaring sources for butterflies.

A total of 8 nature parks designated as "green buffers" to our nature reserves, will be developed over the years © NPARKS

Since 2001, the National Parks Board of Singapore has been introducing these nature parks as "green buffers" 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.

Some of the rarer forest-dependent Awl species found at our nature parks

By providing visitors with alternatives to the Bukit Timah Nature Reserve, these nature parks will help to alleviate issues such as soil compacting, littering, pollution and noise levels at the reserves. At the same time, nature parks serve as physical buffers against urban development for the nature reserves. NParks aspires to "boost the diversity of plants in the nature parks and create a landscape akin to a mature rainforest."

URA's land use plans showing the nature parks as green buffers around Bukit Timah Nature Reserve © Urban Redevelopment Authority

Around BTNR, the nature parks that buffer the nature reserves are Dairy Farm Nature Park (also includes the Singapore Quarry area), Hindhede Nature Park and the future Rifle Range Nature Park. Some of the areas covered by these buffer parks are designated as interim use until such time when the land is required for development. In the recent Draft Master Plan 2019, the areas covered by Nature Reserves, Nature Parks, Utilities and Reserve Sites are clearly demarcated.

© Urban Redevelopment Authority

Although BTNR is a gazetted Nature Reserve, the buffer parks have not been granted such a protected status as yet. However, the benefits of such buffer areas to the nature reserves cannot be understated. Both the Dairy Farm Nature Park and Rifle Range Nature Park are areas of amazing butterfly diversity. During the survey of BTNR, evidence showed that these buffer parks had more butterfly species sighted than within BTNR itself.

Some forest dependent species observed at Dairy Farm Nature Park - Blue Helen, Bamboo Tree Brown and Royal Assyrian

So how effective are these green buffer parks?  In just the past year, after Dairy Farm was "renovated" and the vegetation judiciously managed and native plant species cultivated along the trails and forest edges (in particular nectaring plants), many rare forest-dependent species have been sighted. These species would not have been so easily encountered within BTNR itself if not for the appropriate butterfly-attracting vegetation planted at the adjacent buffer parks along the forest edges and trails.

The Malayan Jester is now a resident species at Dairy Farm Nature Park

One species, the Malayan Jester (Symbrenthia hippoclus selangorana), once very rare, with only a couple of sightings when it was first recorded in Feb 2012 as a new discovery for Singapore, has become a "resident" species at Dairy Farm Nature Park. This species frequents the main trail at DFNP and at times, several individuals have been observed. From the frequency of sightings in 2018/2019 and the pristine condition of the individuals when sighted, it is obvious that there is a viable breeding colony of this species in the area.

Over at the Rifle Range area, which abuts BTNR (at its southern boundary) and which is connected to the Central Catchment Nature Reserves (CCNR), butterfly diversity is also relatively rich. Although BTNR is separated from CCNR by Bukit Timah Expressway, an eco-link was subsequently constructed and opened in 2013 in an effort to reconnect the two nature reserves.

Two uncommon species found at Dairy Farm Nature Park and Rifle Range Nature Park - Yellow Archduke and Hieroglyphic Flat

When the Rifle Range Nature Park (another green buffer to BTNR) is completed in 2020, it is likely to be a good area to spot rarer butterflies that inhabit the forests of BTNR and CCNR, when they come out to feed. The development of these nature parks is good on two counts - firstly, it relieves the pressure on the two nature reserves from visitors, and secondly, it provides for good access for surveys and nature observers to record our local forest-dependent butterfly species.

Two forest-dependent species found at Dairy Farm Nature Park and Rifle Range Nature Park - White Spot Palmer and Banded Yeoman

Some examples of the more notable species of butterflies spotted in the nature parks/buffer parks like Dairy Farm NP and Rifle Range NP are featured throughout this article. Taken by various photographers and butterfly watchers over the past few years, many of the species found in these areas are those that are forest-dependent, and not those that we are familiar with, in urban parks and gardens.

There is therefore an important function of these green buffer parks in the ecological conservation of our main nature reserves. These nature parks that buffer the nature reserves play a critical role in the conservation of our forest-dependent butterfly biodiversity that urban parks and gardens cannot replicate.

Text by Khew SK : Photos by Alan Ang, Goh YL, Khew SK, Michael Khor, Lim CA, Michael Soh, Jonathan Soong and Alson Teo

02 June 2019

Butterfly of the Month - June 2019

Butterfly of the Month - June 2019
The Common Hedge Blue (Acytolepis puspa lambi)

It is the month of June already, and the summer heat is upon us.  I was in India recently, and in particular New Delhi. A few years back, I came across an article that mentioned that the heat was so intense in New Delhi, that the tarmac on the road actually melted! It seemed very far away at that time, and it was not something that I could empathise with, despite Singapore's own "unbearable" heat.

This time around, I experienced the New Delhi summer heat for myself. Even coming out of the airport just past 10pm in the evening was like walking into an oven despite it being late at night. The next couple of days out for site visits, we faced temperatures reaching the mid 40's degC with relative humidities under 20%. Looking back at the article which showed pictures of the tarmac melting, I could personally experience the intensity of the heat now. I do not want to imagine other parts of the Middle East where temperatures can soar to the 50's!

It is always amazing to see how the locals go about their daily business, despite the unbearable heat. Perhaps the human body is so adaptable that it can acclamatise to the environment after some time. But the issue of climate change and global warming is something that is real, and there have been temperature simulations by scientists to show parts of the world that may become inhabitable if the global temperatures continue to increase over the coming decades.

Over in the economic world, global concern for the trade war between the US and China mounts, as tit-for-tat measures continue to cause collateral damage to both sides. The US 'attack' on specific companies like technology company Huawei also triggered retaliatory reactions from China that will only cause misery to companies on both sides of the Pacific, and other countries in the region that have significant trade relations with both the US and China.

Our Butterfly of the Month is the diminutive Lycaenid, the Common Hedge Blue (Acytolepis puspa lambi). A common butterfly in Singapore, the Common Hedge Blue can be encountered in urban parks and gardens, although more often observed in the fringe areas of the nature reserves. It is a fast-flying butterfly, but is regularly encountered puddling on damp footpaths and tracks.

Upperside of a male Common Hedge Blue

The male Common Hedge Blue is shining blue on the upperside, with a black marginal border on both wings. The female is pale greenish-blue with broad black borders on the forewing and heavily black-dusted on the hindwing.

The underside features the usual black and grey spots and streaks on a whitish-grey ground colour on both wings. The species can be distinguished by the small black spot at the base of space 7 on the underside of the hindwing. The marginal cilia is chequered and is more prominent in pristine individuals.

This species exhibits a wide variability in its underside markings, and there have been relatively frequent encounters of aberrant individuals. The position, size and relative adjacencies of the spots and streaks can vary quite a bit from individual to individual, often suggesting that it may be a different species altogether! A blogpost featuring this variability can be found here.

A trio of Common Hedge Blues puddling on bird dropping along a footpath

The Common Hedge Blue has an erratic flight and found flying rapidly amongst low shrubbery. It is partial to human sweat and sometimes stops to puddle on a sweaty forearm or hand of visitors to the parks. It can regularly be encountered puddling on bird droppings on leaves or on forest trails, and sometimes seen in the company of other butterfly species when puddling.

A Common Hedge Blue excretes a liquid "bubble" whilst puddling

The species is sometimes confused with the smaller (and rarer) Malayan (Megisba malaya sikkima). But a quick comparison of the size, the forewing markings and in particular the short hindwing 'tails' on the Malayan, the two species can be easily separated. Over in Malaysia, where there are several more lookalikes, it is harder to identify the cryptic species that appear to be very similar in size and markings to the Common Hedge Blue.

The Common Hedge Blue has been successfully bred on three local plant species in Singapore - Combretum sundaicum, Ventilago maingayi and Prunus polystachya. There are likely to be other caterpillar host plants of this common butterfly which have yet to be discovered.

Text by Khew SK ; Photos by David Chan, May Chan, Chng CK, David Ho, Khew SK, Koh CH, Loh MY, Jonathan Soong, Johnny Wee and Anthony Wong