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Home , Agamidae, Cape rock gecko, Dubious dtella, Goanna, Heteronotia, Heteronotia binoei

No.78 June 2003

Notes from The diverse of Oz the has a great diversity of lizards – as many as 47 different have Editor been found living in a single sand dune. Conditions which mammals find so harsh are apparently not such a disadvantage for . Next to birds, lizards are among the most commonly encountered Next to Antarctica, Australia is the have reptiles exploited an environment in the driest continent on earth – 75 percent largely uninhabitable for other animals. savannas. Indeed, the diversity of of it is arid or semi-arid. The climate is lizards in the tropical savannas is erratic, with long, irregular dry and wet The great diversity of species particularly rich, exploiting cycles determined by the effects of El may be due to the long-term stability, numerous from Nino and La Nina. Successful animals and great size, of the Australian woodlands to sandstone must cope with unreliable rainfall and continent. Those animals which cope escarpments, and prolonged periods of shortages, but well with harsh conditions have had semi-arid zones, many endemic to take advantage of unpredictable times plenty of time to evolve into different just small areas. This Tropical of plenty. In addition, Australia’s soils species exploiting different ecological Topics looks at some of the more are also nutrient-poor with low niches. This diversity may even be widespread and common species. productivity, and fires are frequent. fostered by shortages, favouring large numbers of specialist species which This issue also looks at Energy efficiency is thus the key to have adapted to localised conditions crocodiles. Although not lizards, long-term survival. Mammals and birds over fewer, more widely distributed they are -like in many generate their own heat from food, species which might have evolved in a respects and are important using up to 90 percent of their energy more benign environment. reptiles of the savanna intake for this purpose. Reptiles, waterways. Visitors to tropical however, tap into the abundant solar Reptiles have fared much better than Australia must always be aware – energy to fuel their activities. They are mammals and birds following the and beware – of these fascinating also much more water efficient (see arrival of Europeans in Australia. but potentially dangerous p. 2). When times are lean, since they Over 12 percent of mammals have animals. do not need to eat to maintain body become extinct and over 17 percent heat, reptiles can reduce their have declined, compared with just I would like to thank Russell Best, metabolism and go into a state of one possible reptile extinction. Queensland Parks and Wildlife suspended animation for prolonged Medium-sized mammals weighing Service, and Tony Griffiths, Key periods. between 35g and 5.5kg have been Centre for Tropical Wildlife worst affected. During droughts, Management, Northern Territory The combination of poor soils and dry larger mammals and birds can often University, for their help with this climate is believed to have led to the move to wetter areas. Smaller issue. evolution of plants with tough, thick, mammals, however, have probably chemical-laden leaves and relatively always lived a boom/bust existence – Contents: few plant-eaters. Instead, the those lucky enough to retreat to vegetation is broken down by , wetter refuges eventually able to Page 1: The diverse lizards of Oz which thrive in Australia, providing an recolonise areas where less fortunate Page 2: What makes lizards tick? abundant food source for reptiles. Just animals died out. Nowadays, these House guests; Frills in the fire as mangroves don’t need salt but have refuges attract cattle which compete Page 3: Crocodiles developed strategies for living where for the same resources. In addition, Pages 4&5: Lizards in the no other plants can rabbits have severely reduced savanna compete, so too ground cover and foxes and feral cats Page 6: Questions & answers are serious predators. Changed fire Facts and stats; Tourist Talk regimes also make life difficult for Page 7: Out and about many mammals and birds. Reptiles Page 8: Bookshelf seem more resilient to the same pressures. What makes lizards tick? Lizards are efficient creatures. Instead of consuming food to , legless lizards and will readily drop their tails generate energy, most use solar power, basking in sunshine or when threatened, the wriggling appendage serving as a sleeping in a warm spot to power up their ‘batteries’ for the distraction while the owner makes its getaway. Fracture planes day’s (or night’s) activities. Some lizards, such as dragons, are between certain vertebrae at the top of the tail allow it to able to raise their ribs and angle their bodies to increase the detach easily when pulled apart by special muscles. This body surface exposed and can become darker to absorb more sacrificial offering is easily regrown. Tails of dragons and heat. This strategy, known as active thermoregulating, is not goannas can also break off, but do not do so as readily and an option for some lizards which live in closed forests. tend not to regrow. Instead, they thermoregulate passively, or ‘thermoconform’, their body temperature simply conforming to that of the air All dragons, goannas and Australian geckos lay but around them. some skinks give birth to live young. Viviparity, as this is known, is more common in cool-climate reptiles, perhaps Lizards are also efficient users of water. Their dry scaly skin because the warmer temperatures inside the mother’s body reduces moisture loss, those living in the hottest areas lead to better development of the young. tending to have compact bodies to minimise loss and/or restricting most activities to hours of darkness. In addition, Most lizards are silent, but geckos chatter and squawk, some reptiles do not use water to flush nitrogenous wastes from the species making the characteristic and sometimes startling body as urine, like mammals do, but convert them to a form ‘’ call which has given them their name. Legless lizards which can be dumped as solid dung. may make a high-pitched squeak and some skinks produce a soft squeak. House guests Frills in the fire

Geckos are among the Dubious Fires are common in savanna woodlands so how do they most familiar of dtella affect the frilled lizards which live there? Researchers found tropical animals, that, on the whole, fires benefited these lizards, mainly by living in our houses, removing ground cover and allowing them a better view of scuttling around our ceilings, swarming around our outside potential prey. However, different types of fires have different lights to pounce on dazzled insects and conducting their effects. Fires occurring early in the dry season are less intense affairs behind our picture frames. and do not seem to threaten the frilled lizards, which avoid them by staying in tree canopies. Late dry season fires, on the Several species of geckos qualify as ‘house’ geckos, having other hand, are much more dangerous killing up to 30 percent adopted humans as co-habiters. The dubious dtella ( of the lizards. Many of those studied chose to leave their dubia) is found widely in Queensland and northern New treetop retreats and seek shelter in mounds – a South Wales. Varying in colour from pale pinkish to brown successful strategy which saved their lives. Many, however, with darker markings, it can also be found in the wild on trees stayed in the trees which was much more hazardous. and in rock crevices. Nonetheless, areas burnt by late dry season fires seem to Another species, the house gecko (Hemidactylus frenatus) is provide more food for frilled lizards. Generally, abundance of an import from which has hitched a lift with travelling invertebrates in the lizards’ stomachs decreases – termites by humans. It is now found at the tip of Cape York Peninsula, in more than 40 percent – but there is an increase in numbers of urban areas like Cairns and in the Northern Territory where it ants, which seem more active and abundant in burnt areas. is spreading from Darwin to settlements along the road south Importantly, however, the lack of vegetation cover means that towards Alice Springs. It seems to be dependent on human the lizards can find more, and larger, prey. habitation. This gecko can change colour, becoming pale at night and dark during the day. Although similar in appearance When compared, frilled lizards from areas unburnt for many to the dubious dtella it can be distinguished by its slightly years were not in as good condition as those from regularly spiny tail. It also has a distinctive loud scolding call; native burnt areas; areas unburnt for prolonged periods tended to house geckos make only a soft chattering call. have low populations of frilled lizards. On the whole, areas which are burnt regularly in the early dry season are most The nocturnal lifestyle of geckos prevents them from basking likely to benefit these lizards by in the sun as most lizards do to raise their body temperatures. increasing food supplies but not Instead, they choose daytime retreats which are warmed by threatening the animals’ lives. the sun, particularly in the afternoon, so that they are full of Although late season fires seem energy by sunset. to provide more food, they also Medical researchers are intrigued by Competition for kill off such a large proportion of how a gecko is able to grow a new tail suitable spots can the lizards that the population is without the fluid retention and swelling be fierce, leading unlikely to be sustainable if (lymphoedema) frequently associated to fights between such fires are too frequent. with radical human surgery. The key opponents during Only if increased food seems to be a potent protein growth which they grasp supplies attract sufficient factor, discovered in geckos, which each others’ tails numbers of lizards from enables them to regenerate their in their mouths. neighbouring unburnt lymphatic systems. It is hoped a similar areas would the population product can be developed for humans. remain viable. 22 Crocodiles Croc origins Although they look similar, crocodiles and lizards have a very different ancestry. All evolved from reptiles, which in turn developed digestive enzymes cannot work and food rots in the stomach from amphibians. However, the branch on the evolutionary instead. Both species decrease their food intake during the tree which was to become lizards and diverged from cooler months, and in more southern locations crocodiles may the branch which would give rise to birds, dinosaurs and cease feeding altogether during winter. The growth of crocodiles more than 300 million years ago. Interestingly, crocodiles during the cooler months decreases. birds, dinosaurs and crocodiles all developed the same arrangement for the joining leg and foot at the ankle. This Big-hearted crocs connection in lizard legs is quite different. Crocodiles have four-chambered hearts, like mammals and birds, whereas all other reptile hearts have three chambers. Nonetheless, crocodiles share many characteristics with This difference in structure ensures that the blood flow lizards. For example, they bask in the sun to raise their body system in crocodiles is more efficient. In addition, temperature, lying sideways to give maximum exposure to the crocodiles can control the flow of blood throughout their blood-rich bumpy scales which act as solar panels on their bodies by increasing or decreasing the heart rate or by backs. ‘shunting’ the blood flow to areas of importance such as the heart, brain and muscles and restricting the flow to non- As with lizards, crocodiles can go without food for long essential areas like the intestines. However, some reptilian periods. If a crocodile’s body temperature drops too much, features allow oxygenated and deoxygenated blood to mix, an advantage for a crocodile when diving. Croc types There are about 23 species of crocodilians in the world, two of them in Australia. Estuarine crocodile (Crocodylus porosus) Freshwater crocodile (Crocodylus johnstoni)

This crocodile is found not just in Australia but also in This species is found only in Australia. It inhabits South-east Asia, India and around western Pacific islands. It freshwater rivers, swamps and billabongs throughout is sometimes called the , but this is a northern tropical Australia from Broome in Western Australia deceptive name because these animals are found not just on to Princess Charlotte Bay in Queensland – but no further the coast (and occasionally in the open sea) but also far south on the east coast except where it has been introduced upstream and in many freshwater swamps and billabongs. artificially. It does occur in tidal estuaries, but tends to avoid Almost any body of water in tropical Australia must be areas inhabited by estuarine crocodiles, which sometimes eat suspected of harbouring crocodiles of at least one species. freshies. This species is much smaller than the estuarine crocodile, males growing to about 2m in length – although a Young estuarine crocodiles feed on insects, crabs, prawns 3m male has been caught – and females to about 1.8m. and shrimps, but as they grow in size the amount of vertebrate material in the diet increases. Larger animals attack sea turtles, Freshwater crocodiles feed on fish, insects, crustaceans, small goannas, wallabies, pigs and even cattle; estuarine crocodiles birds, reptiles and frogs, often grasping them with the tip of over 3m in length are a danger to people. Very strong muscles the jaw and manoeuvring them further into the mouth. They are employed for closing the jaws, which can easily crush a do not prey on people but will bite in self-defence. Since some pig’s skull – but a rubber band around the snout of a 2m large freshies take wallabies, children should always be crocodile is enough to keep it from using its weak ‘opening’ supervised near freshwater crocodiles. muscles. Prey, grabbed in the jaws, is usually drowned. Contrary to popular myth, crocodiles do not store uneaten Be croc wise in croc country food and most certainly do not prefer rotten food. Don’t make a croc an offer it can’t resist. • Obey crocodile warning signs, even if you can’t see Adult male Telling the difference crocodiles. estuarine The best way to tell the two Australian • Don’t go swimming or paddling in areas where crocodiles are crocodile species apart is to look crocodiles live. usually between at the skull and jaws. • Keep well away from the water’s edge. 3.3m and 4.5m, but The skull of an • Don’t gut fish, discard food scraps or wash dishes at larger individuals estuarine crocodile the water’s edge. over 6m have been (above) is broad and • Don’t camp within 50m of water. recorded. the jawline is irregular, whereas the skull • Be careful in boats; don’t hang a foot over the edge. Females grow to of a freshie (right) is • Don’t sit in branches above the water – crocs can jump. about 3 to 3.5m narrower and the • Supervise children and be moderate with alcohol intake long. jawline straighter. in croc country – many victims of crocodile attacks had become careless when intoxicated. 33 Lizards in the savanna Dragons (Family ) There are about 60 species of dragon lizards in Australia (330 worldwide). They are active during the day, although some in hot arid zones may come out at night. With well-developed limbs they are good runners, climbers and, in some cases, swimmers. Dragons are able to change colour, becoming dark when absorbing heat and lighter when trying to cool down. Males become more colourful at mating time.

The frilled lizard ( kingii), found throughout the forests and Gilbert’s woodlands of northern Australia, is the only lizard in the world with a frill – a thin dragon or but wide, scaly ruff. When not in use, it is folded loosely over the lizard’s upper Gilbert’s body, but when the is called upon to defend itself, it opens its mouth to lashtail unfurl the frill into a circular ruff which would have been the pride of an Elizabethan ( courtier. Although the frilled lizard is coloured with muted tones of browns and gilberti) is a black which it well in its dry woodland home, the frill, when erect, is common and brightly coloured with patches of yellow and orange. Its owner is now aiming to be relatively large seen and with mouth gaping, it lashes its wiry tail at the enemy. If bluff fails, the lizard (52cm lizard takes off, running along the ground on its hind legs to the nearest tree. total length) with a long thin tail almost Although probably primarily used in defence, the frill, which has numerous blood three times the length of the head and vessels, may also help with temperature regulation. body combined. It is found across the savannas, except in eastern Cape York The frilled lizard spends 90 percent of its time in the trees. It is a ‘sit-and-wait’ Peninsula. Often seen in pairs, some predator which surveys the ground, leaping on food such as ants, termites and males have a white streak on the side of other invertebrates when they show themselves. the head. It likes to perch on any Studies have shown that in the dry season when elevated object – trees, termite mounds, food is scarce, a frilled lizard will climb up into the posts and so on – especially near water. canopy of a tree and stay there for up to three It feeds on ants and any other lizard months as its metabolism drops by as much as 70 which it can subdue. percent. The lizard is aestivating – the equivalent, in a hot climate, of hibernation. By dropping its energy Two-lined dragons live on the ground or requirements, it can thus survive a period of food in low vegetation. They are named for shortage. To lower its metabolism rates the lizard the two pale lines along their backs. must also keep cool so, instead of basking in There are several species, but the the sun it keeps in the shade, shifting around northern two-lined dragon ( the trunk of the tree if necessary to avoid the bilineata) is one of the most sun. widespread, found across northern Queensland and the Northern Territory. This impressive lizard is one of Australia’s It lives in savanna woodland, largest dragons, growing to 95cm in total sclerophyll forests and sandy country. length. Well camouflaged, it perches on low branches, looking out for insects to ambush. Goannas (Family ) Goannas tend to be large lizards (although the pygmy goanna of the central is, at 25cm total length, the smallest goanna in the world). They are also among the oldest; early versions were around to see the dinosaurs and even the modern versions dating back 15-20 million years. Although found elsewhere, Australia has the lion’s share of goanna species with about 25 of the world’s 30. Thought to be the most intelligent of lizards, they eat a variety of other animals, both living and dead, including other reptiles, insects, baby birds and mammals, including possums. At home on the ground and in trees, they constantly flick their forked tongues, picking up scent particles from the air and transferring them to a structure known as the Jacobson’s organ, on the roof of the mouth, where they are interpreted. The spotted tree monitor (Varanus scalaris) is found across Gould’s goanna (Varanus gouldii) is found in most parts of the northern tropics almost anywhere there are trees, darker continental Australia, although it tends to prefer sandy areas individuals inhabiting and lighter ones in drier and avoids rainforest. Reaching 1.5m in total length, and areas. The varied patterns of this species tend to match local weighing several kilos, Gould’s goanna is black with varying tree trunk colours but most have spots of some sort, usually amounts of yellow. It is at home on the ground, rarely climbing pale with a dark centre. This lizard hunts on the ground as well trees, as it seeks prey of many types – insects, lizards and as in the trees, but if disturbed on the ground, will beat a their eggs, and small hasty and noisy retreat up the nearest tree, disappearing into mammals – and a hollow or keeping on the opposite side to its pursuer. It scavenges for carrion. feeds on insects, It digs holes or uses smaller lizards tree logs or other animals’ and baby burrows as retreats. Eggs are laid birds and may in a deep burrow which is then drop as much as closed and concealed by the 4m from a tree on female. to prey. 64 Spotted tree monitor illustration by Eleanor Torr Skinks (Family Scincidae) These are the most numerous of lizards with 1300 species in the world and about 300 species in Australia, found in all environments. They tend to be smooth and usually glossy. Most eat insects, some eat other lizards and others eat fruits, flowers, leaves and fungi. The major (Egernia frerei) is found along the east The common bluetongue lizard (Tiliqua scincoides) at 56cm coast of Queensland to the New South Wales border and in total length, is one of the world’s largest skinks. It is found Arnhem Land, patterns and colouring varying according to across the northern tropics (but not in rainforest) and along location. It is a large skink, up to 39cm in total body length, the eastern and south-eastern part of the continent. It is a thickset and generally glossy brown, and can be seen sunning thickset lizard with small legs and a more-or-less banded back itself at the edge of open forest or rainforest. It eats insects, which varies according to location. It can be active on warm snails, other lizards and vegetable material and lives in small nights as well as during the day, and eats insects, snails and communities in complex burrow systems. vegetable material such as fruits. When alarmed this skink opens its pink mouth, hisses, and sticks out a dark blue The related and similar, but tongue in confusingly named warning. If Egernia major is this is commonly known ignored, it can deliver a as the land mullet. painful bite. Generally slow- It is found in moving, it can move rapidly if south-east necessary. There are several Major skink Queensland and species of bluetongues, all of northern New South Wales. which give birth to live young. Geckos (Family ) There are more than 90 gecko species in Australia, most of them under 20cm in total length. These are nocturnal lizards although they may be active in dark places during the day. They feed only on prey which moves, such as insects and smaller geckos. A gecko’s eyes are permanently covered with a transparent eyelid, perhaps to reduce evaporation. Unable to clean its eyes with tears, the gecko licks them with its tongue. Some gecko species are parthenogenic, meaning that the females can produce offspring without male input. The spiny-tailed gecko (Diplodactylus Bynoe’s gecko ( binoei) is ciliaris) is found in woodlands and very common throughout most of the , westwards from western Australian mainland. Also known as the Queensland, living in trees or other prickly gecko because of its bumpy skin, vegetation. It is also frequently seen on it thrives in all types of from roads. This is one of 10 ‘tail-squirting’ forests and woodlands to arid areas. It species. It can eject an offensive and shelters in crevices, under logs and in sticky liquid from the spines of its tail. rocks, but at night searches open By lifting its tail it can aim the fluid ground for insects – and other geckos. More than 30 of the accurately up to a distance of 30cm. This These geckos sometimes lay eggs in gecko species gecko is also particularly good at communal nests which may contain up found in Australia changing colour from dark to very pale. to 150 eggs. belong to the Diplodactylus . The fat-tailed diplodactylus ( Diplodactylus conspicillatus) is found only on the Legless lizards (Family ) ground in stony and grassy areas Legless lizards are quite closely related to geckos, sharing many characteristics. across much of the top of Australia, its They occur only in Australasia with 33 of the 35 species restricted to Australia and colour varying to match the habitat in two found also in New Guinea.They are sometimes called flap-footed lizards which it lives. About 10cm in total because, while they lack forelimbs entirely, they still have a scaly flap where the length, it has a bulbous tail which acts hind legs once were. Their loss would probably have enabled these lizards to fit as a fat storage organ, and feeds on better into small spaces in vegetation and rock crevices and to burrow in soil. They termites and other insects. are also called -lizards due to their obvious resemblance. However, they have broad, flat tongues, not forked ones, and move with more regular curving The fat-tailed diplodactylus spends its movements. They stay out of sight most of the time, basking in upper layers of leaf days in underground holes such as litter and soil and moving in the open only at night if possible. abandoned burrows of trap-door spiders, blocking the entrance with its Burton’s snake-lizard ( burtonis) is the most widely distributed of the legless fat tail to keep out predators and keep in lizards, living in most habitats except for rainforest. It can grow to 62cm in total moisture. It is sometimes called the length. It has a long, pointed head, quite unlike any snake’s, and is very variable in burrow-plug gecko. Most adults have colour, even within populations in small areas. Although most legless lizards eat lost their original tails which are insects, this species feeds almost exclusively on other replaced with more rounded ones which lizards, ambushing them when they come close. make even better burrow-plugs. It can swallow a lizard with a girth greater than its own. It is active by day and night, but prefers to keep out of sight by day and tends to be nocturnal in hotter regions. Burton’s snake-lizard 75 QUESTIONS & ANSWERS Facts and stats Q Is it true that predator birds, such Q How many species of as crows and hawks, will carry a live are now Corymbia and is there a list of There are about 6400 reptiles in the world ember from burnt bush to start new them with descriptions? Why were with roughly 700 in Australia. These include fires elsewhere, so increasing their they changed? Can you suggest where snakes, lizards, turtles and crocodiles. hunting opportunities? to get scientific names? Goannas are also known as monitor lizards. A Black kites are sometimes called ‘fire A In 1995, all bloodwoods and ghost Varanus, their scientific family name, comes hawks’ because they collect in large gums were given their own genus, from the Arabic word for monitor because numbers above fires, looking for Corymbia. A genus is a category for these lizards had a reputation for warning insects, small mammals and reptiles grouping together species which have of the approach of a crocodile – they were fleeing from the blaze. The idea that descended from one ancestor and, as a monitoring the situation. The word they also actively spread fires is often result, are closely related. However, ‘goanna’, used only in Australia, is derived repeated. I have been unable to find differences in the DNA as well as other from the Spanish word ‘’, originally anyone who has actually seen this but structural differences, such as leaf used for large American lizards. am assured that it has been observed anatomy and flower structure, showed by reliable naturalists in the Northern that there were actually two groups A 5.5m long , a goanna with Territory and that it has also been within Eucalyptus, which is why the ancient origins, was present in eastern reported from – black kites are a change was made. Australia as recently as 30,000 years ago widespread species. Nevertheless, Corymbia are still given and would have crossed paths with Aboriginal settlers. Dr Penny Olsen of the Australian the common name eucalypt. Initially National University wrote in response 113 species were included, but a few more have since been added so the Largest Australian skink status is claimed to this query: “I have heard it but for both the land mullet at 58cm total length imagine it’s likely that the kite grabs total is currently about 130. This some poor creature fleeing the flames number will change as more species are and the common bluetongue at 56cm total and in doing so gets a fistful of described. length. Largest dragons are the eastern burning grass or whatever, which it water dragon and the frilled lizard, both then drops. However, black kites have The decision to separate Corymbia growing to about 95cm total length. learnt to drop chips into water to ‘fish’, was published by botanists Laurie so who knows?” Johnson and Ken Hill in Telopea 6 The largest Australian goanna is the (2-3), a journal issued by the Royal -dwelling which can grow If any readers have personally seen Botanic Gardens, Sydney. Ian Brooker, to 2.5m in total length but it is dwarfed by this behaviour, I would be glad to author of Eucalypts of Australia (three the massive Indonesian , know about it (editor). volumes) does not agree and does not another goanna which reaches lengths of include the name Corymbia in his 3m and can weigh as much as 250kg. Crows are very clever birds, though books. Appendix 4 of Hill and whether they too are arsonists is Johnson’s paper gives a table which Some geckos are able to perform gravity- thought unlikely. Certainly they are shows how the names used by Brooker defying feats, walking on ceilings and on adept at using and even creating tools, correspond to Corymbia. However, it panes of glass, thanks to numerous little though. A captive New Caledonian may no longer be in print. A list of hooked bristles on the soles of their feet crow was observed bending a piece of Queensland Corymbia species can be which give them an astonishing grip. wire to make a hook to retrieve food, found in Names and Distribution of Scientists in California are hoping to repeating this many times. For more Queensland Plants, Algae and produce synthetic versions which could details about this see the website: Lichens, a Queensland Herbarium publication. be used to improve shoes for athletes and //news.nationalgeographic.com/news/ tyres – and perhaps make ceiling-painting 2002/08/0808_020808_crow.html Acknowledgements to John Clarkson, Queensland Parks and Wildlife Service. easier! No Australian lizards are venomous. The only venomous lizards in the world are the Gila monster and bearded lizard of north TOURIST TALK America. ENGLISH GERMAN JAPANESE Geckos must be on guard against lizard Eidechse tokage inadvertently sharing their hidey-holes diverse vielfältig kotonatta with predatory snakes but tests with reptile Reptil hachurui Lesueur’s velvet gecko, found in south- east Queensland and coastal New South solar energy Sonnenenergie taiyo enerugi Wales, have shown they are able to not hibernate überwintern toumin suru only detect the odour of a snake, but efficient effizient nouritsuteki na distinguish potential predators from harmless snake species. frill Halskrause furiru crocodile Krokodil kurokodairu The smallest lizards in the world grow to estuarine an der kakou just 16mm from snout to vent – scarcely Flußmündung long enough to stretch across a 10 cent coin. Two related species of geckos, they tail Schwanz shippo live on islands in the Dominican Republic and the British Virgin Islands. 66 Out and about Woodswallows Look out for are among the freshwater jellyfish. many nomadic Although not exactly birds of the savannas well-known, these which move creatures have been according to food found in most parts of the world and in supplies. every Australian state except Tasmania. White- James Cook University researcher, Lisa- browed ann Gershwin, is keen to find out how woodswallows widespread they are. They are likely to may Brilliant red flowers appear on coral be found across the tropics, in any calm trees (Erythrina variegata) during the appear in flocks of 100 or more, water bodies such as dams, fish ponds, dry season, usually sprouting from bare following locust swarms. They tend to shallow pools and slow-flowing branches, the tree having temporarily move north in winter, returning south in waterways. lost its leaves. Rich in nectar, these spring and summer and nesting when peaflowers are popular with birds such conditions are good, thus taking Restricted to fresh water, the jellyfish as honeyeaters. The stems and advantage of the unpredictable are white or colourless, delicate and lacy branches are covered with small black Australian conditions. and about the size of a 5 or 10 cent coin. prickles which tend to become longer They are probably found all year in when the tree is subjected to water White-breasted woodswallows also tropical areas often appearing in large stress but dropping off as the stems tend to move north in winter, arriving in numbers when they can look like drifting enlarge. large numbers to feed on grasshoppers snowflakes in the water. They then tend and other insects. They are usually seen to disappear within months or just This tree is found in open forest and high in the sky around sunset catching weeks, not appearing again for maybe woodland often on shallow, gravelly moths in flight. These birds are seldom 5–10 years. It is possible they are soils and behind the beaches. It is also a found far from water and have an transported on the feet of waterbirds. native of India, Malaysia and Burma. endearing habit of sitting side by side, With seeds which can float in salt water, snuggling together in groups and These jellyfish eat small aquatic it has been able to spread by sea. In preening each other. invertebrates, including mosquito larvae Photos by Lisa-ann Gershwin Asia, this tree is put to a number of Acknowledgements to Stuart and are thus a potentially important agricultural uses – leaves provide a Traynor mosquito control. good fodder for stock and the wood is They may have a mild used for fences, light packing boxes, sting, but this is paper pulp and fuel. Its deciduous habit thought to only affect is put to good use by farmers who use people with very the trees to support pepper, vanilla, sensitive skin. betel and yam vines which need shade during the hot wet season, but If you come across appreciate sunshine in the cool, dry these animals, season. Lisa-ann Gershwin would love to hear from you. You can contact her by phone: 4781 6446, or email: Recently a ranger in Cape Tribulation, Caesalpinia bonduc is a prickly vine [email protected] There is an in north Queensland, discovered a known as nicker nut and also as wait-a- American website on freshwater jellies: tourist bus stopped on the road in the while, although it is quite different from nsm1.nsm.iup.edu/tpeard/thing.htm vicinity of Noah Creek with its hazard the scrambling, thorny rainforest palm of lights flashing. Passengers had that name. It grows in monsoon vine alighted and were standing around a thickets mainly near the coast, although sub-adult cassowary. Cassowaries are it can also be found quite far inland, large, unpredictable and potentially possibly where seeds have been Male great bowerbirds are busy around dangerous birds – people should not accidentally carried. Because the seeds their bowers from April until November approach them. In this case the tour can float, and remain viable in salt water or December, emitting harsh, rasping operator did not seem concerned that for several years, these plants are found calls and hoping to attract females. he was putting his passengers at risk. in coastal regions throughout the Found throughout the northern More vehicles stopped and soon the Pacific, Asia and even America. savannas, these birds can be very road was blocked in both directions as numerous in the denser woodlands, people wandered around a very Scrambling or climbing to a height of 3m particularly near water. The male’s confused cassowary. or more, this legume has yellow bower is a dense avenue of upright peaflowers which are followed during twigs arranged in parallel, curving walls. We all love to see a cassowary but the the dry season by oval, slightly heart- It is decorated with white stones and chances are strong that this particular shaped, brown, woody seed capsules shells and green fruits, glass and so on. bird will be next seen dead on the road. which are covered in dense spines. The male tends to rebuild his bower For the safety of both cassowaries and These open to drop rounded dull, olive- each year, often next to the old one. people, these animals should not be green seeds which resemble animal After mating the female goes off to nest approached and should never be droppings or balls of plasticine rather and raise the young on her own while encouraged near roads. than seeds. They are collected by great the male continues to attend the bower, bowerbirds. hoping to attract more partners. 77 BOOKSHELF

Reptiles and Amphibians of Australia Australian Crocodiles: A Natural Australian Journal of Ecology (1996) Harold G. Cogger History 21, 386-398 Reed New Holland, Sydney (2000) Grahame Webb and Charlie Manolis The effects of fire on the frillneck Reed New Holland, Sydney (1998) lizard (Chlamydosaurus kingii) in This is the standard reference book for northern Australia Australian reptiles. This extremely informative book looks A.D.Griffiths and K.A. Christian at all aspects of crocodiles. Encyclopedia of Australian Animals: The Future Eaters Reptiles Lizards of Australia Tim Flannery Harald Ehmann Stephen Swanson Reed New Holland, Sydney (1997) Angus & Robertson, Pymble (1992) Angus & Robertson, North Ryde (1990) Tim Flannery’s famous book looks at Each species has a brief description diversity and extinctions, among many plus interesting information on special Forty Queensland Lizards other things. features and behaviour. There are also Floyd D. Dale photos and distribution maps as well Queensland Museum, Brisbane (1973) Nature Australia Vol 26 No 5 Winter as a good introduction. 1999 Nature Australia Vol 27 No 6 Spring Home Geckonomics Australian Tropical Reptiles and 2002 Sharon Downes Frogs Goannas, first-class monitors Clifford and Dawn Frith Steve van Dyck This article is about Lesueur’s velvet Frith and Frith Books, Malanda (1991) gecko.

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