Official Opening of Dairy Farm Nature Park

Official Opening of the Dairy Farm Nature Park
5 Sep 2009


A view of the Dairy Farm Nature Park Visitor Centre

Yesterday, 5 Sep 2009, saw the official opening of yet another environmental offering from the National Parks Board in Singapore. With the opening of the $5.7M Dairy Farm Nature Park and the Wallace Education Centre, Singaporean nature buffs can now enjoy another gateway to the Bukit Timah Nature Reserve via the 63 Ha Dairy Farm Nature Park.

Located on the northern boundary of the Bukit Timah Nature Reserve, and off Dairy Farm Road, the Visitor Centre of the Dairy Farm Nature Park boasts a small sheltered gathering area and an open landscaped toilet for users of the park. A new carpark with a relatively good number of parking lots will delight drivers who used to park at the Hindhede area. A second carpark off Upper Bukit Timah Road near the MOE Adventure Camp also offers users of the Bukit Timah Nature Reserves another alternative location to start off their nature walks.

Minister Mah delivering his speech

The Dairy Farm Nature Reserve & Wallace Education Centre was officially opened by Minister for National Development, Mr Mah Bow Tan. Received by a sizeable crowd of nature enthusiasts and school children, Minister shared the many new parks and nature offerings from the National Parks Board to the enthused crowd. Amongst the projects will be an interesting concept of creating a new 50m wide nature link between the Bukit Timah Nature Reserve and the Central Catchment Nature Reserve over the Bukit Timah Expressway (BKE). The bridge, 50m wide at its narrowest point and planted with dense trees resembling a forest habitat, could help populations of animals like the critically-endangered banded leaf monkey to recover.



The Wallace Education Centre also serves as a exhibition and learning facility for nature enthusiasts to meet and share their knowledge with others. Converted from an old dairy farm, the building houses two big exhibition halls and some meeting facilities. The building is a nice example of architectural conservation and adaptive re-use of a utilitarian agricultural building.

The spanking new Wallace Education Centre at Dairy Farm Nature Park

At the exhibition on opening day was a chronological history of the area, and some nature dioramas featuring the flora and fauna of the Dairy Farm area. An ecological learning lab converted from an old cowshed offers programmes developed with partners Raffles Girls' School and the National University of Singapore, and sponsored by GlaxoSmith-Kline.

On the school side of the exhibition were booths featuring recycling and nature appreciation from various school participants. One of the booths also featured butterfly appreciation and conservation, and I was amused to note that many of the photos from the Raffles Girls School exhibit were taken from ButterflyCircle members' works (probably without permission! :-p) Anyway, it's for a good cause and our works were used to enhance the girls' mission to promote butterfly conservation.

The Dairy Farm Nature Park also features a number of well-marked trails, one of which celebrates the renowned 19th century naturalist, Alfred Russel Wallace who did a lot of work walking the trails and collecting at Bukit Timah Hill and the surrounding area during his time in Singapore.

A special trail is also dedicated to Wallace. Many trails also link to the Bukit Timah Nature Reserve and the nearby Zhenghua Park.

It was a nice event, and I had the opportunity to meet old friends from MND, NParks, NUS School of Design and Environment, nature enthusiasts and also to make new acquaintances with like-minded people in the nature community in Singapore.

A lost hiker checks out the map of Dairy Farm Nature Park

With the opening of this new facility, nature enthusiasts now have better accessibility and parking amenities to another area of the Bukit Timah Nature Reserve, and hopefully, alleviate the over-crowded conditions at the Hindhede Road side of the Nature Reserve. ButterflyCircle members now also have another location to conduct butterfly surveys and photography, and perhaps soon add more species to the Singapore Checklist!

Text & Photos by Khew SK

Additional News : NParks opens new Dairy Farm Nature Park to protect biodiversity

Butterfly of the Month - September 2009

Butterfly of the Month - September 2009

The Archduke (Lexias pardalis dirteana)

This month we feature another species that exhibits sexual dimorphism - the Archduke. This species is seasonally common in Singapore's nature reserves, and found mainly on shaded forest paths and amongst undergrowth amongst tall trees. The species is seldom seen in open sunny areas, and is a forest-dependent species.

The Archduke belongs to the genus Lexias which consists of rather large, robust and fast flying butterflies. The Archduke is the commonest species of the genus found in Singapore, often encountered feeding on rotting fruits and other organic matter amongst forest litter.

A female Archduke forages on the ground for nutrients

The males are dark velvety black above with a broad blue distal border on the hindwing, which is continued narrowly along the termen of the forewing. The underside is deep ochreous brown with yellow spots. The larger female is dark brown above, and profusely spotted with yellow above and white on the undersides. The underside of the hindwing is pale grayish green. The apical portion of the antennal club is orange in both sexes and this distinguishes this species from the closely-related and very similar Black-Tipped Archduke (Lexias dirtea merguia).

The female Archduke is a good example of adaptation by natural selection to camouflage itself better to escape predators like birds. Its dark brown and yellow-spotted wings render it almost invisible as it feeds on the forest floor with dappled sunlight. As many observers will attest, the Archdukes tend to fly rapidly from underfoot when disturbed, as one walks towards their favourite feeding spots along damp forest paths littered with dead leaves and twigs. As they land to feed again, they blend in well with their surroundings, particularly more so with the female.

The robust body of the Archduke is an indication of the powerful flight that it is capable of. Once alarmed, the Archduke takes off rapidly with a few wingbeats, and glides amongst the undergrowth. The species is a relatively large butterfly, attaining wingspans of up to 150mm in the larger female.

The caterpillar has a rather unique appearance with branched spines that allows it to camouflage itself well on the upper surface of its host plant, Cratoxylum pruriflorum. The branched spines terminate with attractive orange-and-black tips that make the caterpillar appear unfriendly. However, it is not poisonous at all, and can be touched without any danger.

An Archduke's "baby photo"

In Singapore, there are two lookalikes to the Archduke and may be confused with this species. They are the Black-Tipped Archduke (Lexias dirtea merguia) which has males and females correspondingly similar to the Archduke, except that the antennae of the latter species is black instead of orange. The other species is the Yellow Archduke (Lexias canescens pardalina) in which both the sexes resemble the female of the Archduke, but are smaller in size. All three prefer shaded habitats in the forest understorey in the nature reserves of Singapore.

Text by Khew SK ; Photos by James Foong & Khew SK

Life History of the Blue Spotted Crow

Life History of the Blue Spotted Crow (Euploea midamus singapura)

Butterfly Biodata:
Genus: Euploea Fabricius, 1807
Species: midamus Linnaeus, 1758
Subspecies: singapura Moore, 1883
Wingspan of Adult Butterfly: 80mm
Caterpillar Local Host Plant: A plant in the Apocynaceae family, specific ID to be determined.

Physical Description of Adult Butterfly:
Above, the wings are blackish brown, usually without the blue sheen seen in other Euploea species. The termens are slightly crenulate and there are marginal and submarginal series of white spots, with submarginal spots in spaces 6, 7 and 8 rather large and elongated. on the forewings. There is also a white spot in the cell and a few distal spots. Underneath, the markings resemble those on the upperside. The male has a small and narrow brand in space 1b on the forewing and a pale yellowish scent patch in the cell area on the hindwing.



A Blue Spotted Crow feasting on the flowers of a Syzygium plant in the nature reserve.


A Blue Spotted Crow puddling on the cement floor of a shelter hut in the nature reserve.

Field Observations of Butterfly Behaviour:
This Singapore subspecies of the Blue Spotted Crow is uncommon in Singapore, and is rarely seen. Sightings of the slow flying adults includes individuals or small groups visiting flowers and puddling. One rare occasions, several adults could be seen flying around shelter huts built alongside trails in the catchment area, with some even puddling on the cement floor of the shelters. Although mostly confined to the nature reserves, some individuals have also been observed in housing estates.

Early Stages:
Elsewhere in its range of occurrence, host plants recorded for this species are mainly members of the Apocynaceae family, examples are Strophanthus divariatus and S. divergens in Hong Kong, S. dichotomus, Nerium oleander and Roupellia sp. in Java. As for the singapura subspecies of the Blue Spotted Crow, thus far only one host plant, which has opposite leaves and pale yellowish sap (lactiferous), has been located in the local nature reserves. The caterpillars of Blue Spotted Crow feed on the young and tender leaves in its early instars but move on to the more mature and larger leaves in the later instars.

Local host plant for the Blue Spotted Crow found in the nature reserve.

The eggs of the Blue Spotted Crow are laid singly on the young leaves of the host plant, typically on the underside. The yellow eggs are tall (about 1.8mm in height) and somewhat cylindrical (diameter: 1mm) with a rounded top. The egg surface is ribbed.

A mother Blue Spotted Crow laying egg on a young leaf of the host plant.

Left: fresh egg; Right: mature egg. Note the black head is visible in the mature egg.

The egg takes about 3 days to hatch. The young caterpillar emerges by eating away part of the egg shell. The rest of the egg shell becomes the first meal for the newly hatched, which has a length of about 2.3mm. Its cylindrical body is pale yellowish. The large head capsule is black in color. A pair of short and inconspicuous protuberances can be found on the dorsum of each of the following four segments: 2nd and 3rd thoracic segments, 2nd and 8th abdominal segments.


Two views of a newly hatched caterpillar eating the egg shell, length: 2.3mm.

Once the newly hatched moves on to feed on the young leaves over the next few hours, its body starts to take on a green undertone. The growth is rather rapid with the body length doubling in one day, and after just 1 to 1.5 days from hatching, it moults to the 2nd instar. Towards the final hours of the 1st instar, the 8 protuberances turned orangy brown and become more marked in appearance. This period of growth also brings along blackened ends for all 8 pairs of legs.


Two views of 1st instar caterpillar, late in this stage, length:5.5mm.

The body of the 2nd instar caterpillar is again yellowish orange with a green undertone. The most obvious change is the lengthening of the 8 protuberances to short processes, each of which is almost entirely dark brown to black. There are two small brown spots on the dorsum of the prothorax, and one large black patch on the posterior end of the body. This instar lasts only 1 to 1.5 days with the body length reaching 11mm before the moult to the 3rd instar.


Two views of a 2nd instar caterpillar, late in this stage, length: 11mm

The 3rd instar caterpillar is similar in appearance to the 2nd instar caterpillar with the only change being the proportionally longer processes. This instar takes about 1-1.5 days to complete with body length reaching about 16-17mm.


3rd instar caterpillar, newly moulted, length: 6mm


3rd instar caterpillar, late in this stage. .Lengths: 9mm (top) and 11mm (bottom).

Retaining very much the same body features from the earlier two instars, the 4th instar caterpillar distinguishes itself in having proportionally longer processes which have the tendency to flex forward with ends slightly curved. This instar lasts 1.5 to 2 days with the body length reaching about 27mm.


Two views of a 4th instar caterpillar, late in this stage, length: 27mm.

The 5th and final instar brings along a slightly more dramatic change in appearance. Now the 8 processes have become very long and filamentous, with the tapering ends having a strong tendency of twirling. The spiracles have also become more prominently marked in large black spots.


A newly moulted 5th instar caterpillar, with its exuvia trailing behind.

One surprising and exciting find during this breeding exercise is the discovery of adenosma being present in this Euploea species, a first for the Danainae subfamily. The Blue Spotted Crow caterpillars, at least for the singapura subspecies, readily flash their adenosma when they are disturbed. This yellow-colored adenosma could be easily observed in both the 4th and 5th instars. Refer to the pictures and youtube clip below for an illustration of this adenoma, which is located just ahead of the 1st pair of the thoracic legs. As can be seen in the pictures, the caterpillars of Blue Spotted Crow also adopt the characteristic on-guard posture with the anterior body arched and the head tucked beneath the thorax.

The on-guard stance of an early 5th instar caterpillar, length: 30mm.

The same caterpillar as in the earlier picture, this time with its adenosma everted.

The eversion of the adenosma of a 4th instar caterpillar of the Blue Spotted Crow.

Two views of a 5th instar caterpillar, length: 40mm.

The 5th instar lasts for 4-5 days, and the body length reaches up to 47mm. On the last day, the caterpillar ceases feeding, and its body becomes shortened but with no change in body color. It wanders around in search of a pupation site. Typically it comes to a halt on a branch/stem or a leaf underside, where the caterpillar spins a silk pad from which it soon hangs vertically to take on the pre-pupatory pose. Within the few hours prior to pupation, the caterpillar gradually relaxes and lengthens to a straight posture. Waves of contraction soon travel from the the rear end to the head until the pupation event kicks in.

Pre-pupatory larva. Left: early stage; Right: late stage with the onset of pupation only minutes away.

The pupation event of a Blue Spotted Crow caterpillar (shown at 10x speed).

Pupation takes place 0.5 days after the caterpillar assumes the hanging posture. Typical of the pupae within the Nymphalidae family, the pupa of the Blue Spotted Crow suspends itself from the silk pad with no supporting silk girdle. Initially, the pupa is bright yellowish orange, but the surface gradually takes on a silvery metalic glitter about a day later. The pupa is rather rotund, and has a few black spots and dark brown patches on the dorsum. Length of pupae: 20-22mm.


Three views of a fresh pupa of the Blue Spotted Crow.

Three views of a shining pupa of the Blue Spotted Crow.


Three views of a mature pupa of the Blue Spotted Crow.
The prominent submarginal spots can be seen in the wing pad area.

After about 6 days of development, the pupal skin turns translucent as the development within the pupal case comes to an end. The spots on the forewing upperside also become discernible. The following day, the adult butterfly emerges from the pupal case. It then perches nearby to expand and dry its wings before taking its first flight.

A newly eclosed Blue Spotted Crow drying its wings on its pupal case.

A newly eclosed Blue Spotted Crow.

References:

• The Butterflies of The Malay Peninsula, A.S. Corbet and H.M. Pendlebury, 4th Edition, The Malayan Nature Society.
• A Photographic Monograph on Hong Kong Butterflies, Volume 1, Hong Kong Lepidopterists' Society.
  
• Butterflies of Thailand, Pisuth Ek-Amnuay, 1st Edition, 2006

Text by Horace Tan, Photos by Anthony Wong, Henry Koh and Horace Tan

Two Minds, One Theory

Two Minds, One Theory
Wallace & Darwin - The Two Faces of Evolution Theory

As part of the year-long events celebrating the 150th Anniversary of the Singapore Botanic Gardens, the exhibition on the Evolution Theory, first discussed by Charles Darwin and his lesser-known counterpart, Alfred Russel Wallace is currently being featured at the Botany Centre of the SBG.

The exhibition discusses Natural Selection and the Theory of Evolution as first postulated by the two intellectuals after spending a lot of time circumnavigating the globe and observing a profusion and diversity of life forms. The search for an explanation to understand long-term organic change brought them to many parts of the world then unfamiliar with the western civilisation.

Between the two intellectuals, A.R. Wallace spent many years in the Far East, collecting thousands of specimens in his research. In 1869, he published his landmark work, the Malay Archipelago, elaborating his theory of evolution. Wallace also made significant contributions to biogeography when he linked the geographical distribution of animals and plants to the regions' geological history.

Alfred Russel Wallace (1823-1913) - Ardent beetle & butterfly collector, naturalist, biologist, socialist, prolific Victorian writer, biogeographer and thinker

Whilst in Singapore, Wallace explored Bukit Timah collected 700 species of beetles. The incredible productivity at Bukit Timah is an illustration that we live in a region with one of the richest biodiversities in the world.

Amongst his collections, Wallace also collected numerous species of butterflies in the region. As a collector and a scientist, Wallace wrote in his book, the Malay Archipelago, a rather graphic and emotional account after successfully capturing the spectacular Wallace's Golden Birdwing (Ornithoptera croesus) at Batchian, Moluccas in 1858.

He noted that "On taking it out of my net and opening the glorious wings, my heart began to beat violently, the blood rushed to my head, and I felt much more like fainting than I have done when in apprehension of immediate death. I had a headache for the rest of the day. So great was the excitement produced by what will appear to most people a very inadequate cause".

Wallace's Golden Birdwing (Ornithoptera croesus) Male (above) and female (below) Plate from Reise Fregatte Novara. Zoologischer by Rudolf Felder and Alois Friedrich Rogenhofer

Wallace is also credited with describing many butterfly species for the first time, and amongst those was the famous Rajah Brooke's Birdwing (Trogonoptera brookiana) which Wallace first described in 1855.

Wallace is credited with first describing the famous Rajah Brooke's Birdwing in 1855 after a specimen was given to him by the then governor of Sarawak, James Brooke.

In recognition of his work, many later researchers also paid tribute to Wallace by naming new organisms after him. Amongst butterflies, one famous local subspecies of the Blue Pansy is the most well-known. The Blue Pansy (Junonia orithya wallacei) had the subspecies named after Wallace by the collecter Distant in 1883.

The local subspecies of the Blue Pansy was named after Wallace

The SBG Exhibition traces some of Wallace's journey in the Far East, and explains some of his theories and findings. Interestingly, he is also credited with giving the Durian, the name "King Of Fruits"! He was a converted durian eater, and actually enjoys eating the fruit that many westerners avoid.

Some of Wallace's theories on natural selection, displayed in butterflies, are mimicry, camouflage, masquerade, sexual dimorphism and so on, can be seen in Singapore's butterflies. At the SBG exhibition there are also many specimens of butterflies around the displays and nature dioramas.

At the Launch of the Exhibition, I also gave a short talk on Natural Selection, adaptation and survival strategies with particular reference to butterflies. I was honoured to have, amongst the distinguished guests in the audience, personalities like Minister George Yeo, Professor Tommy Koh and nature guru, Ms Ilsa Sharp.

The exhibition lasts until 31 Aug 2009, and for those who have yet to catch this exhibition in tribute to Alfred Russel Wallace, you have about a week more to visit the display at the SBG Botany Centre.

Text & Photos by Khew SK (except where indicated)

• Further Reading : Straits Times 22 Aug 09 : Natural History - A Common Heritage for Singapore - Dr Chin See Chung, Director/SBG