SINGAPORE In Gynacantha, it is probable that the increased size and efficiency of the eyes make possible the swift and often erratic flight. Nevertheless, it is likely that Gynacantha escapes the ever present danger of spider webs not by keenness of sight but by sheer bulk and momen- tum. It is common to find a fully adult Gynacantha with bits of spider webs attached to its wings or body, strands which would have proved the undoing of other smaller . Crepuscular flight is probably an adaptation to the food supply, as there is a big burst of small fly- ing everywhere at dusk. It could also be that there is reduced predation from birds during the crepuscular hours. The Gynacantha species typically cease to fly as soon as the bats begin. The common aeshnid Lesser Green Emperor ( guttatus) inserting eggs into sub- It is very difficult to observe these merged reed. Photo: Francis Alvin Lok. wildly darting forms when they are in full flight. It is far easier to observe them Giant Hawker (Tetracanthagyna plagiata) female, in characteristic aeshnine position with down-hanging abdomen. Photo: Tay Soon Lian. by flushing them from their diurnal roost. When flushed, they usually fly a short distance and alight on some twig or stem, or in the undergrowth, in char- acteristic aeshnine position with down- hanging abdomen. Ode to Curious about their specific Text by Cheong Loong Fah, Tang Hung Bun and Robin Ngiam Wen Jiang identification, we have actually caught them by hand. Examining their wings and appendages under a field magnify- With a new book out soon about dragonflies Nowadays, T. plagiata vies with a couple ing glass, we have been rewarded with of other giants for the honor of being the discovery of aeshnid species new and (order Odonata), odonating recognized as the world’s largest known to , like Gynacantha dohrni, (i.e. watching dragonflies) is about to take off living . Heliaeschna crassa, and Heliaeschna unin- ervulata. in Singapore in a big way. Here we provide Hawkers () T. plagiata, like many other members Dragons Of The Air an introduction to help beginners find their of the Aeshnidae family, exhibits a cre- (Gomphidae) puscular lifestyle. However, the evening No spectacle of the odonate world is way amongst a conspicuous and fascinating A Dingy Duskhawker (Gynacantha subinterrupta) female with its large eyes. Strands of spi- hours in our forests really belong to more awesome than the flight of the der webs can be seen attached to the wings and bodies. Photo: Cheong Loong Fah. group of . those aeshnid species in the gomphids, especially the swirling skir- Gynacantha. Like a conjurer’s trick, mishes of gomphids in their territorial tails, like the very common Common of the forest canopy, defying observa- these large, swift-flying hawkers appear battles. They make incredible twists Flametail Ictinogomphus decoratus. While tion. Even those that are not arbo- ragonflies are truly kings largely unchanged throughout evolu- from the dark inner space of the for- and turns, seemingly able to make 180 the club itself would seem to carry an real tend to be extremely wary and are of the air. One of the tionary time. It belongs to the family est during this moment of transition degree turns at full speed in little more energy cost in long-distance flight, it inclined to take evasive action very most majestic in appear- Aeshnidae, which is considered to be between day and night. They create than their own body length. They make might act as an excellent counterbalance quickly. The result is that except for a ance is the Giant Hawker one of the most archaic indeed, evi- an active kinetic pattern in the dim aeshnids look slow! When gomphids are to enable tight high-speed turns. Some few common species, many gomphids DTetracanthagyna plagiata. Its wingspan denced by the fact that, like damselflies, evening landscape with their tireless and present, there is always a sense of drama gomphids lack clubs but have rather elude even the most experienced odona- that can go up to a whopping 160mm, females possess well-developed oviposi- energetic flights, yet they always have a in the scene. As they launch their long long abdomens, which might serve the tologists and avid naturalists. Most are which is larger than that of a sunbird. tors with which to insert their eggs into slightly unreal and supernatural appear- slingshot trajectory high into the blue same function of keeping the high-speed pronounced “rarely seen in the wild”. Watching this enormous creature flying plant tissue or soil. Damselflies hark ance. While watching dragonflies by the sky, they scorch the air with the power turn under control. In Singapore, Ris’ Clubtail about in the swamp forest, it easily feels back about 300 million years. It was sun-dappled streams has its charm and and speed of their flight. Gomphidae is one of the more Leptogomphus risi and Malayan as if one is transported to a lost world. the time of invertebrate gigantism when romance, beholding these spectral forms Gomphids are sometimes given speciose families, yet the least well Spineleg Merogomphus femoralis are Indeed, T. plagiata belongs to an the wingspan of the extinct dragonfly appearing at dusk in the silent shade the common name of clubtails because known. Many gomphids forage high recent discoveries. The former is ancient noble lineage that has remained order Protodonata exceeded 700mm. also has a mysterious allure. quite a number of gomphids have club- above the vast unexplored green ocean classified as rare and local by Orr

8 Nature Watch Jan - Mar 2010 Jan - Mar 2010 Nature Watch 9 (2005), whereas for the latter, only a Dragons Beware— but an illusion; they are ephemeral habi- single male specimen is known from Preys And Predators tats after all, liable to dry up after the . The two Burmagomphus spe- Some of the best habitats for watching monsoon rains. cies, Splayed Clubtail B. divaricatus and the spectacle of odonate life are at those Here in these rainwater-filled Lesser Splayed Clubtail B. plagiatus, are rainwater-filled low-lying areas like Tuas basins, as elsewhere, one can observe only recorded from Singapore in their and Marina East. It is a special moment two main modes of dragonfly hunting. larva form; no adults have been seen in when one arrives early in the morning The fliers catch and typically consume the wild. hours. The mist blurs the sense of time their prey while flying, while the perch- Looking through many of the and place, and all reminders of man are ers take off from an observation post, Peninsular Malaysia species, we find lost. Then the scene changes as the sun catch their prey and return, often to the many gomphid species whose status rises. As the air is heated up, the drag- same spot, and consume it. Many drag- are also pronounced as rare, such as onflies are stirred into frenzied action. onflies are strong and fast fliers, capable A Blue-throated Bee-eater (Merops viridis) Acrogomphus malayanus, A. minor, of reaching speeds of up to 50-60 km/h. with a dragonfly along the Nee Soon pipe- This sense of urgency seems not just a line trail. Photo: Morten Strange Onychogomphus duaricus, O. thien- response to the rise in temperature, but Their wings have a sophisticated archi- emanni, O.aemulus, etc. We suspect that a pattern of life characteristic of dwellers tecture of veins, which ensure that the some of these species could be present of ephemeral habitat. The timelessness wings are stable enough to bear such in Singapore too. of these marshes in the morning mist is speeds. On the other hand, hidden amidst the lush aquatic vegetation are many delightful Lilliputian damselflies, which are all perchers. While damselflies are slower, they are capable of exquisite

wing control that facilitates forward- Charming Flashwing (Vestalis amoena) feeding on a cranefly. Photo: Cheong Loong Fah. reverse flight and deft maneuverability. Except for some specialists, most odonates are opportunistic foragers and have a catholic diet. However, as prey, A Blue-tailed Bee-eater (Merops philippi- flies and mosquitoes (dipterans) out- nus) has just captured a Saddlebag Glider number all other taxa. The celebrated (Tramea transmarina). Photo: Lee Tiah Khee. naturalist W.H. Hudson once described how, on the pampas of Patagonia, the appearance of a foraging dragonfly was welcomed by travelers, because it resulted in the instant departure of the Some odonates are

Common Flametail (Ictinogomphus decoratus) is by far the commonest member of its fam- known to take large ily. Photo: Cheong Yu Jia. prey, even equal to their own body size, A Pied Fantail (Rhipidura javanica) has the most dramatic grabbed a female (Brachythemis contami- being cannibalism. nata). Photo: Wei Luen Chan. clouds of mosquitoes and blackflies that had been pestering them. Unfortunately, here in Singapore, the effect of dragon- flies is not as dramatic in terminating the flight of the mosquitoes. Some odonates are known to take large prey, even equal to their own body size, the most dramatic being can- nibalism. For instance, the libellulid Variegated Green Skimmer Orthetrum sabina and the coenagrionid Ornate Coraltail Ceriagrion cerinorubellum both Robber flies in the family Asilidae are exhibit strong tendency for cannibalism. also a threat to dragonflies. Here one has The locally rare Banded Hooktail (Paragomphus capricornis) emerging in the morning captured a Diplacodes sp. Photo: Cheong hours. Photo: Cheong Loong Fah. The term is here used in its zoological Loong Fah. An Orthetrum sabina feeding on a Tyriobapta torrida. Photo: Cheong Loong Fah.

10 Nature Watch Jan - Mar 2010 Jan - Mar 2010 Nature Watch 11 meaning, referring to a species eating Some odonate species occur in sev- members of its own kind, not always to eral colour forms which are genetically species level. inherited rather than age-related. For Adult odonates themselves form example, mature females of Common important prey items. Birds that fly as Bluetail Ischnura senegalensis, a common well as or better than dragonflies have in open ponds and marshes, dragonflies at a disadvantage, not only are polymorphic. They occur in three in terms of their ability on the wing, but colour forms: olive, orange and one form also because they have better eyesight. that resembles the male (andromorph), Examples are the smaller falcons such as i.e. green on the lower part of the thorax the falconets and kestrels, and the drag- and azure blue on the abdomen segment onfly hunters par excellence, the bee- The sight of the Yellow-Barred Flutterer Rhyothemis Phyllis, another Libellulid, with its 8 and the sides of segment 9. eaters. The duels between the bee-eaters brown and orange batik colour, gliding over our open woodlands, is emblematic of our It has been proposed that male- and the dragonflies are always fascinat- countryside. Photo: Cheong Loong Fah. like morphs in female Odonata serve to ing to watch, and as the prey and the protect females from being harassed by predator re-enact this perpetual dance males. This theory was supported by the between life and death, one cannot help During the monsoon fact that female polymorphism occurs but admire their superb flying skills. months, the open more often in species where males There are also birds that hunt search for mates, but less so in families in the marsh vegetation taking adult spaces over both in which males are territorial (whereby damselflies, such as bitterns and herons our urban and rural females can shun harassment by avoid- (family Ardeidae). They find the dam- Green Metalwing (Neurobasis chinensis) with dorsal green iridescence on hind wings. ance). There is still much to be discov- selflies at a disadvantage because of the areas are invaded by Photo taken in Endau Rompin. Photo: Cheong Loong Fah. ered about this topic. slow flight necessary to dodge between the upright sedges, cattails and similar The Wandering Glider (Pantala flavescens) dragonfly migrants like Sexual behaviour and has a broad wing base that is adapted for territory plants. lengthy gliding rather than strong flight. the Wandering Glider Photo: Cheong Loong Fah. The sexual behaviour of the odonates Migration Pantala flavescens... is one of the most fascinating aspects of During the monsoon months, the open detected substantial migratory move- their life history. There are various issues spaces over both our urban and rural ments over the ocean at night and at They are also known as of interest, such as whether it is the areas are invaded by dragonfly migrants heights of up to 1,000m. Nevertheless, the “Storm Chasers”, males or the females who control the like the Wandering Glider Pantala fla- how they achieve this navigational feat mating – in other words, does female vescens. These migrants fill the air with is still poorly understood. It is one of seeking temporary choice occur in the odonate world? their effortless gliding motion. They those commonplace miracles that keeps pools created by the The complicated mating system of the are also known as the “Storm Chasers”, alive our sense of wonder and makes us Odonata also offers many possibilities seeking temporary pools created by the go out to the field time and again! heavy monsoon rains for mechanical isolation of species, both heavy monsoon rains and laying their Whereas bird migrations are true during tandem and copulation. Thus, eggs in them. Their ability to spot a rain return movements in which an individu- and laying their eggs it will be worthwhile to first under- pool is so acute that any smooth, shiny al migrant completes one or more round in them. stand the reproduction behaviour of the object can attract their attention. Thus trips between breeding and non-breed- Common Bluetail (Ischnura senegalensis) female andromorph, resembling the male it is Odonata. females can often be found absorbed in ing areas during its lifetime, dragonfly Colour and polymorphism mating with. Photo: Tang Hung Bun. Most of the dragonflies that one the futile task of laying eggs on the roof migrations are thought to be intergenera- With their brilliant iridescent hind sees around ponds or ditches are adult of a parked car. Some evidence suggests tional movements in which an individual wings, the males of Green Metalwing males. Around the water, adult males that this species may actually hitch a migrant carries out a migration in only (Neurobasis chinensis) are among the of some species establish territories ride with storm systems—even, perhaps, one direction, with its offspring making most conspicuous and well-known for breeding, and they will drive away with hurricanes—in order to be per- the return trip at a later time. inhabitants of clear forest streams intruders by sparring, flight contests fectly poised to take advantage of fresh P. flavescens has a highly acceler- throughout the region. When the and threat displays of bright colours on breeding habitats. ated life cycle that allows it to get in and takes to the air during courtship, the the abdomen or wings. The territorial P. flavescens is the most cosmopoli- out of ephemeral pools before they dry slow hind wing beat produces bright defense behaviour of some species is tan dragonfly in the world, found in up. The larvae feeds with exceptional flashes of metallic green to attract the indeed very spectacular to watch. both hemispheres to about 40 degrees aggression and appetite and can go from females. The renowned odonatologist For example, the beautiful Fiery latitude, and on such remote land egg to adult in a blistering six weeks. M.A. Lieftinck was so impressed by their Gem (Libellago aurantiaca) can be seen masses as Hawaii and Easter Island. It is The emergence of adults from a rain beauty that he rapturously called them engaged in aerial territorial disputes, a consummate glider and can glide for a pool can be a real spectacle, with huge the ‘Birds of Paradise’ among Odonata. where two males face each other and few hours on end. It has been recorded swarms forming, and moving off en Sadly, N. chinensis is now probably make forward movements without from ships in the middle of the ocean masse in search of new breeding sites, extinct in Singapore due to habitat bodily contact. They hold their nearly and at 20,000 feet in the Himalayas. which could be on an entirely different motionless forewings forward to display destruction. No specimen has gladdened Two male Fiery Gems (Libellago aurantiaca) engaged in aerial territorial dispute. Photo: Recent radar studies in have continent. our eyes for almost the last 50 years. Tang Hung Bun. the dark apical spots while their flight is

12 Nature Watch Jan - Mar 2010 Jan - Mar 2010 Nature Watch 13 maintained by the flapping of their hind wheel and it is known as wheel posi- wings. This can go on for more than tion. This may take place while the two half an hour until one of the males flees dragonflies are perched, and last several the territory. to many minutes, or in flight and be Females typically spend most of over in seconds. In some species of their adult life away from the water, damselflies, during the wheel position, foraging in the nearby trees, bushes and the pair’s slender bodies form a delicate grasses. They come to the water only romantic heart shape. when they are ready to mate. Sperm displacement Tandem Position A female dragonfly can mate repeatedly When a male encounters a receptive Shorttail (Onychargia atrocyana) in tandem position. The insect in front is the male. Photo: with different males. She stores sperm female in the breeding site, he will Tang Hung Bun. from various matings in a special recep- use the anal appendages to clasp her tacle within her body near the tip of securely behind her head (dragonflies) her abdomen. Fertilization of the eggs or prothorax (damselflies) to form a tan- takes place only as they are being laid. dem pair. This action usually takes less This offers the opportunity for the next than a second. At this stage, the couple male to displace the sperm stored in the is said to be “in tandem position”. Some female’s sperm-storage organ delivered species (e.g. damselflies in the family to her during her previous mating. Calopterygidae) show complex court- Dragonfly males are endowed with ship rituals before this stage. Tandem multi-purpose penises fashioned with pairs of dragonflies and damselflies can brushes and hooks to physically remove Blue-spotted Flatwing (Podolestes orientalis) ovipositing by cutting a slit in a plant stem. occasionally be seen flying about, the or displace rival sperm from the female Photo: Tang Hung Bun. female behind the male. reproductive tract. In some dragonflies, the multi-purpose penises can also pro- bank. If the eggs are deposited above Sperm transfer Look-alike Sprite (Pseudagrion australasiae) in sperm transfer (left) and wheel position vide sensory stimulation to the females the waterline, the newly emerged larvae Odonata sex involves a bizarre step, (right). Photo: Tang Hung Bun. during copulation to induce ejection of reaches the water by either falling, or unique among insects. Before a male any previous sperm received. Hence, in by a series of spasmodic hops caused by can mate with a female, he must first dragonflies, mating first will not ensure arching its whole body and flicking itself “mate” with himself. The male genitalia, paternity. This explains why some male into the air. There have been occasions where sperm are produced, open under dragonflies appear to be paranoid about when females oviposit on unsuitable abdominal segment 9, near the tip of guarding against rival males. surfaces such as oil slicks and vehicles, the insect’s abdomen. The male insect mistaking them to be a water surface. also has secondary genitalia at segment Egg laying 2, near the base of the abdomen. The After the completion of copulation, the Odonate Conservation in secondary genitalia include a sperm couple may split up, or they may stay Singapore storage reservoir and a penis. Before he together through oviposition, i.e. egg In a fast developing Singapore the con- Spine-tufted Skimmer (Orthetrum chrysis) can mate with a female, the male has to laying. In some species, the male guards ovipositing by dipping her abdominal tip to servation of our natural heritage is of transfer sperm from the tip of his abdo- the female from the competition of the water surface. Photo: Tang Hung Bun. utmost importance. In particular, the men into the storage reservoir at the rival males. In other species the female conservation of dragonflies faces a huge base of his abdomen. The male achieves is left alone to lay her eggs. Guarding cuts a slit in a plant stem or leaf and challenge, as wetlands and streams are this by curling his abdomen beneath his may take several forms. The most basic inserts a single egg. Egg laying may be constantly under threat from urbanisa- body, and touching the aperture of the form for damselflies is contact guarding, above the waterline, at the waterline or tion. One example is the recent conver- sperm duct on the 9th segment to the where the male stays attached to the even below the waterline — sometimes sion of the Tuas marsh into a motorcycle Shorttail (Onychargia atrocyana) in wheel position. Photo: Tang Hung Bun. opening of the sperm reservoir at the female for the entire egg-laying process. so deep that the insect plunges below circuit. It is poignant to know that the base of the abdomen. Depending on the Many dragonflies employ hover guard- the surface for many minutes, possibly marsh is the only place where the rare species, this takes place either before or ing, in which the male hovers above or obtaining oxygen from the water via a Hooked Midget Mortonagrion falcatum after the male has formed a tandem pair perches near the female as she is lay- thin air pocket that is trapped in the damselfly is recorded so far. Thankfully with a female. ing eggs. A hover-guarding male may fine hairs on its body. dragonfly conservation in Singapore has attempt to protect several of “his” egg- In many Libellulidae species, the also taken a step forward. In our nature Copulation - Wheel Position laying females at a time. The oviposi- female dips her abdominal tip to the reserves the value of stream biodiver- After the male’s sperm transfer and the tion method varies according to species water surface and washes off her eggs sity has been realised and is now under couple achieving the tandem position, and/or circumstances. while hovering or flying, often at high appropriate conservation management. the female curls her abdomen forward In the family Aeshnidae of drag- speed. Some species scatter their eggs Furthermore, the creation and enhance- to link the tip with the male’s second- onflies and in all families of damselflies, over the water from the air and some ment of ponds in public parks to attract use splash-laying to throw drops of dragonflies has been initiated. Already, ary genitalia in order to receive sperm. A pair of rare Scarlet Adjudant (Aethriamanta brevipennis) in tandem (left) and wheel the female is equipped with a curved, The male and female form a heart shape (right) positions while in flight. Photo: Tang Hung Bun. blade-like ovipositor with which she water containing eggs onto plants or the ponds harbouring rare species have been

14 Nature Watch Jan - Mar 2010 Jan - Mar 2010 Nature Watch 15 identified for management. The natu- ralisation of our waterways by PUB’s ABC program will surely create more dragonfly habitats, see http://www.pub. gov.sg/abcwaters/abcwatermasterplan/ Pages/default.aspx for details. In terms of outreach, dragonfly talks and courses have been conducted, and dragonfly sto- ryboards have been produced in some parks. The Nature Society (Singapore) With enhanced dragonfly appreciation in Singapore, these large and beautiful This rare Mortonagrion falcatum used to live at Tuas Marsh, which has been converted into insects have the a motorcycle circuit. Photo: Cheong Loong Fah. potential of becoming a flagship group of Dr. Cheong Loong Fah started out as a species for freshwater birdwatcher, but now he likes to roam the forest searching for insects, including the conservation in general. dragonflies and the various beetle families. also played a significant role by adopting He has written a series of articles, on both the Kranji Marsh, thereby preserving a birds and insects, in a column provided by good dragonfly habitat. Plans are also in the Chinese press. place by the Society to conduct dragon- fly-watching trips for its members. Tang Hung Bun Bishan Park is one of our best parks for has always been a So what can you do to help con- dragonflies. 33 species have been recorded nature lover. Inspired by Loong Fah, he serve Singapore’s dragonflies? It is easy. so far. Photo: Robin Ngiam. started watching dragonflies in 2005. In Just go out and enjoy odonating (drag- 2009, he retired early from teaching and onfly-watching) in the many accessible now expends his energy on writing a book places such as park ponds and nature on the dragonflies of Singapore. reserves. Take pictures of them, observe their behaviour, and share your findings with fellow dragonfly lovers. You can Robin Ngiam chased dragonflies during also post dragonfly pictures on websites his childhood kampong days. Those fond like Dragonfly (http://www.asia- memories have developed into a deep pas- dragonfly.net/index.php). You might sion for them. That passion is deepened even discover a new species or some new Toa Payoh Town Park has a very accessible further after getting acquainted with the aspect of odonate behaviour. pond for dragonfly watching. Photo: Robin Ngiam. co-authors, who are his dragonfly men- Also, spread the message of no tors and friends. He has just completed a Editor’s note: littering and no releasing of unwanted Odonata is an order of two-year dragonfly conservation project in pets in our forest streams and ponds to insects that includes dragonflies and dam- NParks. safeguard the freshwater habitats. One selflies. The word Odonate is an English should also be aware of the harmful version of this term. The last published effect of pesticide usage on the integrity checklist in 2008 contained 117 odonate REFERENCES of the aquatic habitats. species recorded from Singapore. Since Norma-Rashid, Cheong, Y.L. F., Lua, H.K. & Dragonfly-watching is already very 2008, more new records have been made, D.H. Murphy (2008) The Dragonflies (Odonata) of Singapore: Current Status Records and Collections popular in places like , , US pushing the number of species to 124 of the Raffles Museum of Biodiversity Research. and Europe. With enhanced dragonfly currently. An updated checklist will be Raffles Museum of Biodiversity Research, appreciation in Singapore, these large published in a dragonfly photo identifica- Singapore. and beautiful insects have the potential tion guidebook by Tang Hung Bun, Wang Orr, A.G. (2005) Dragonflies of Peninsular Malaysia and Singapore. Natural History of becoming a flagship group of species Luan Keng and Matti Hämäläinen in Publications (Borneo), Kota Kinabalu. for freshwater conservation in general. May this year.

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