The wild wet

The green season, as the has been dubbed, is a time of magnificent skyscapes, dramatic torrential and vigorous rushing rivers. It is also a ime of celebration as rain, the life force of the , revitalises and The regions animals which have been suffering from the stress of a prolonged . glorious high rainforest draped mountains recieve 2010 was the wettest for reach the east coast, while in signficiant rain from the effect called Queensland since records were first kept other we may receive rain from occult ( stripping). in 1887 (and ’s fourth wettest three or four. In El Niño years, the Up to 31% of annual rain occurs this recorded year). south-easterly tend to way. That is why we enjoy the lovely break down. continually flowing creeks we love to The average annual rainfall is 1992mm swim in around the region. Oh what on an average 154 days. The majority Essentially, rain patterns in the wet a life! of the region’s rainfall occurs during tropics are variable. Older residents summer between January and March. talk about the wet of the past, The mean annual rainfall ranges from but they are remembering years when about 1,200 to over 8000 millimeters Summer rain in the wet tropics comes rainfall, for a number of reasons, was (nix 1991). Even in the wettest areas from a convergence of patterns. above average. There really is no between Tully and there is The trough is a long band typical wet season. Australia as a a distinctly seasonal precipitation of activity formed where the south- whole is subject to long, irregular regime with over 60 per cent falling east trade winds (blowing towards the patterns and the wet tropics is in the summer months (December to north-west) meet equatorial westerlies no exception. By the end of the wet March) followed by a relatively dry (blowing towards the south-east). season, our dams could well be full season in mid-year. and overflowing again. The collision of these two warm, wet, Tropical low presssure cells and rising air streams results in heavy rain cyclones that develop in the associated with and monsoonal trough commonly occasional tropical cyclones, which form produce more than 250 millimeters of over the ocean. The rain in a day during the wet season. sometimes shows up on satellite images Mt Bellenden Ker has recorded 1,140 as a solid line of cloud but at other times millimeters of rain and 24-hour is scattered and ill-defined. In some period and in 2000 recievevd over years, the monsoon trough does not 12m of rain. go far south of Cooktown. In other years it reaches southern Queensland The combination of extreme rainfall and even New South Wales. over an extended period of time and many intense cyclones during the rain comes from south-easterly same period created unseasonally winds dropping their moisture as they flooded conditions in the whole of rise up over the mountains of the Great the east coast of Australia, seriously Dividing Range. The annual rainfall total affecting many people from Sydney to varies, of course, from one year to the Cape York. next. Sometimes the monsoon trough is more or less active than usual. Many wet weary locals questioned Cyclones, which usually bring a large Queensland calling itself the amount of rain in a short period, can “sunshine state”. greatly affect the total; some years no It’s all in the name Cooper’s wood, humbug, leather jacket, red almond, red ash, red tweedie, mountain ash, sarsparilla, soapbush, soapwood and foam bark. These are the common names for not several plants but just one, the rainforest pioneer tree Alphitonia excelsa. At least half of these names are also used for the other four species of Alphitonia found in north Queensland.

So, as we see here, not only are several combine both the first and second common names often used for the name as in Lenbrassia, which same but sometimes the same was named after Len Brass, a common name can refer to several Toowoomba-born botanist noted ifferent plants. This can lead to great for his work in many tropical parts confusion. The use of scientific names can of the world. help avoid this. Names describing features of a The application of scientific names to plants plant usually have Latin or Greek is governed by an internationally accepted set roots. Xanthostemon chrysanthus, of rules, the International Code of Botanical golden penda, the attractive yellow-flowered tree and floral Nomenclature. Under this system one plant species emblem of Cairns, gets its name from the Greek xantho- meaning can have no more than one ‘yellow’ and -stemon, ‘stamen’, the male parts of name and no two plant species People are sometimes reluctant the flower. Chrysanthus is another Greek word can share the same name. The to use scientific names but meaning ‘golden-flowered’. Eucalyptus grandis, naming system we use today may do so unawares. Did you the flooded gum or rose gum, gets its species was popularised by the Swedish know that Chrysanthemum is a name from the Latin adjective grandis which botanist Carl Linnaeus and dates scientific name? means ‘large, great, big, tall or lofty’, all perfect from 1753. A scientific name descriptions of this gum tree. consists of two parts and is referred to as a binomial. The first part, the genus, Sometimes a name indicates the country of origin, for example, is written with an initial capital letter. The second australiensis meaning ‘from Australia’ (not to be confused with part is the species name (or specific epithet) and australis, which means ‘southern’) and novoguinensis, ‘from New is written entirely in Guinea’. Notice these all end in lower case. You can -ensis, the Latin suffix indicating a think of the genus as There are no rules for how plant names are formed but country or place of origin. a noun and the species as an adjective, they generally adhere to the rules of common sense and describing the noun. For example, public acceptability. They can be drawn from allmanner The name could also indicate there are black cows and there are of sources but, regardless of their origin, the names something about the place where brown cows. Similarly you can have are treated as Latin. Hence, grammatically, they have the plant is commonly found. For gender, number and case. This explains why theendings black horses or brown horses. Cows example, in monticola the Latin of specific names can differ slightly between genera. For and horses can be likened to the genus ending -cola means ‘dweller’, so example, angustifolia means narrowleaved but we have plants with this species name and the colour to the species. Callicarpa angustifolia, Stenocarpus angustifolius and Canthium angustifolium because Callicarpa is feminine, are mountain dwellers, from the A plant can be named after the person Stenocarpus is masculine and Canthium is neuter. Latin mons, ‘a mountain’. Another who discovered it, a noteworthy way of indicating habitat is to person, a patron, friend, lover, wife, use the ending –arius, indicating husband or partner. These names end in -ii if the person is a man a connection. For example arenarius means ‘pertaining to sand’ or -iae if the person is a woman, although the initial i is sometimes (arena); Xanthostemon arenarius is a tree (with yellow stamens) dropped for various reasons. Miliusa traceyi, a tree from several from the sand dunes at Cape Flattery. rainforest types on , is named after the botanist Geoff Tracey. Argophyllum verae is An existing name may be modified. This is named after the botanical illustrator, Vera commonly used for generic names where a Scarth Johnson. The species name can prefix such as neo-, ‘new’, or pseudo-, ‘false’, commemorate more than one person. is added to an existing name, hence Neolitsea In this case, the name will end in from Litsea and Pseudopogonatherum -iorum or -iarum although, again, the fromogonatherum. Alternatively a suffix can be ii is sometimes omitted. Cupaniopsis used, for example, -astrum added to Malva to cooperorum is named after artist form Malvastrum indicating ‘an incomplete likeness’. and authors Bill and Wendy Cooper. When inter-generic crosses have been created, names may be People can also be commemorated compounded. This commonly happens with orchids. For example, in generic names. For example, when Epidendrum was crossed with Cattleya the offspring became Banksia is named after Sir Joseph Epicattleya. Sometimes anagrams are formed by rearranging the Banks. Gossia, a recently described letters of an existing name. Hence the name Romnalda, a grass-like genus related to Austromyrtus, is plant from Mount Lewis, was coined by rearranging the letters of named after former Queensland Lomandra, a plant which looks quite similar. premier, Wayne Goss. The genus can Acknowledgements to John Clarkson, QPWS

Tropical Topics updated 2011 Creature feature: Blind snakes Facts and stats Blind snakes (Ramphotyphlops spp) are Studies of the feeding habits of blind on Orchids small, worm-like, non-venomous snakes snakes indicate that they follow The word ‘orchid’ with small eyes which feed mainly on the scent trails of ants which live in comes from the Greek ants and termites. There are about 30 colonies. These ants leave pheromone word ‘orchis’ which species in various parts of Australia and markers as a guide for other individuals means testicle, a perhaps eight in the wet tropics. The in the group. Blind snakes were reference to the larger species of blind snakes can grow observed placing their snouts on the paired tubers to 40cm in length. All have smooth trails and flicking their forked tongues of the plants from which bodies with thick skin which is thought as they followed them. They ignored the group got its name, to protect them from the stings of trails of ants which are solitary foragers about 2300 years ago. This is one of the ants, a useful characteristic since they and therefore rarely leave a scent as a largest of flowering plant families with at specialise in invading ant nests and guide to their fellows. They also ignored least 230 species found in the wet eating their eggs and larvae. trails of earthworms and termites. tropics. They grow in a wide variety of Some large blind snake species, situations, some of them on the ground Their small eyes are little more than protected by their thick scales, feed in and some as epiphytes on trees or on lightsensitive spots below the body the nests of ferocious stinging bulldog rocks (lithophytes). scales; more developed eyes would ants. probably be vulnerable to ant attack Many orchids are pollinated by insects and be at risk of abrasion as the snake Small ones, however, can be stung which are provided with special ‘landing wriggles through underground burrows. and die as a result. Blind snakes live platforms’ on the flowers. The labellum in all types of habitats from deserts to (lip), as this is called, is actually part of Curiously, however, embryonic blind tropical rainforests. Some are restricted the top of the flower but, in most snakes have normalsized eyes, which to very limited locations. Harmless, species, the flower twists round during suggests that their eyes became smaller non-venomous and largely defenceless, development so that the labellum is as they evolved a burrowing lifestyle. they fall prey to bandicoots, birds, cats more conveniently situated for visiting Blind snakes spend most of their time and other snakes, notably the black insects. below the ground or in leaf litter, though and white striped bandy bandy which Some orchids use sexual deception to some maintain permanent tunnels in ant is believed to feed exclusively on blind trick male insects into visiting them. or termite nests. When moving snakes. They mimic the shape and scent of forward through burrows they use a female insects and deposit packets of small spine on the end of the tail as In north America, screech owls pollen on males which are fooled into an anchorage point. carry local blind snakes to their trying to mate with them. Presumably nests where they are employed to they are slow to learn, because they Blind snakes sometimes emerge into the feed on insect larvae which would then carry this to the next flower, open at night to cross hard surfaces or otherwise parasitise the chicks. performing sexual services for the orchid when the earth is saturated by rain. They instead. have even been observed swimming in clear water and some have been found One seed capsule may contain as many quite high up in trees. as four million tiny seeds, as fine as dust. Unlike the seeds of other plants they do not contain any nutrients for the germinating plant. Instead, the seed must meet up with a mycorrhizal fungus. The two set up a mutually beneficial relationship without which the orchid seed would not germinate and grow. Only a small proportion of the seeds gets lucky.

Epiphytic orchids have roots with an outer spongy layer of cells, up to 18 layers thick, which can rapidly absorb water. Mycorrhizal fungi may also reside there. Swollen stems, and some leaves, store water and food reserves.

Tropical Topics updated 2011 Revitalising Rain By the end of the dry season, our wet tropics is the not-so-wet and rather brown tropics. Suddenly, thanks to the rain, the area is green again and flourishing.

River levels are at their first . Some, such as sooty grunter and certain catfish, lowest at the end of the make their way upstream seeking flowing water which they dry season. Pools are need for breeding. Other fish, such as barramundi, ox-eye stagnant, oxygen levels herring and jungle perch, move in the opposite direction are low and accumulated swimming downstream as soon as the rivers begin to flow organic material is making well. They must breed in salt or brackish water; their sperm, the water increasingly eggs and/or larvae cannot survive in fresh water. Although acidic. When the some young barramundi will spend their lives in estuaries, start, volumes of water most move upstream within their first two months and come rushing through the remain in fresh water until they are mature and ready to creeks, flushing them out breed themselves. Wet season floods facilitate their journeys. and clearing channels. Early in 2003, fishers noticed serious delays in barramundi As waters spread beyond mating and spawning, presumably due to the extended dry the banks, they carry the season, and were concerned that future barra stocks would organic material and sediment, enriching the floodplain. suffer as a result.

Life in tropical waterways has evolved with water pulses – times of low levels and times of flood. Many animals are sensitive to this and time their breeding accordingly. Nutrients, washed into waterholes by the first storms, fuel an increase in growth of algae and small invertebrates, a valuable source of food for the young of many species. Early rains, therefore, are a trigger for many animals to breed.

Rain stimulates frogs to breed. The males call as a reflex when rain falls and this attracts females, which may Waterbirds in Australia tend to be nomadic, their movements carefully choose the best singers for mating. Frogs have dictated by rainfall. When the wet season begins they spread suffered particularly badly in the past few years due to poor out, moving away from the shrunken pools and billabongs wet seasons. which served as a refuge during the long dry season. Flooding provides ideal conditions for many of these birds to breed. Those which did try to reproduce had Indeed the sexual cycle in some ducks is triggered by an difficulty in finding suitable watery increase in water level. In southern Australia, where most rain breeding sites and, if successful, often falls in winter, this may be while in the north it occurs lost their progeny when puddles dried as the wet season sets in. up. Some females carried their eggs so long they were no longer viable when laid. In addition, lack of insect food led to malnutrition and many frogs died from diseases. The onset of rain brings frogs out in the open as they optimistically make for the nearest water in the hope of mating. Most male frogs have an inflatable vocal sac below the lower jaw. When calling, the frog inflates this sac through holes or slits on either side of the tongue. Acting as a resonance chamber, the Australian white ibis nest in coastal wetlands. They wait until sac amplifies the frog’s call; a small group of calling frogs can water reaches at least a metre in depth in their breeding be heard up to a kilometre away. Although most frogs’ vocal grounds, just to be sure it will not dry up. The male defends sacs inflate externally, in some species it inflates internally his territory aggressively and the pair nests on a platform of so the entire body of the frog swells up. Some male frogs do vegetation in low bushes. If the adventurous young fall in the not have vocal sacs. These water, they are able to swim frogs tend to live in noisy, to safety. fast-flowing streams. Instead January rains led to an explosion of fungal fruiting. Mushrooms of attempting to compete have been popping up in decorative clusters, but a number of When the rains start, magpie with the background roar, people have been given hospital geese feed on young shoots treatment after eating them. they may signal their of grass until wild rice seeds Consuming the wrong intentions by simply waving provide enough food for them to prospective partners. mushroom can have fatal results so beware! Eat only what to breed, usually from March Many fish, particularly those you buy in the shops or grow yourself. to June. in lagoons, breed after the

Tropical Topics updated 2011 Water soaking into the roots of the plants leads Beautiful white and to a flush of growth, the new leaves on many black pied imperial tropical plants glowing pink, red or bronze. pigeons, with their The pigment, anthocyanin, which creates this soothing cooing calls, colourful display, may act as a sunscreen to are a summer feature protect the tender young leaves as they are of our forests and developing. The leaves of most rainforest plants taper to gardens. These birds a point at the end. This ‘drip-tip’ serves to drain the water have a delightful habit of quickly off the leaf. Lichens and algae, which would interfere soaring into the sky and with the leaf’s ability to photosynthesise, are less likely then suddenly dropping to grow on dry leaves. Warm, dry leaves are also able to down again, their white photosynthesise more efficiently than cold, wet ones. plumage sometimes Pied Imperial Pigeon image courtesy of Deb Pople highlighted against a Many trees flowered prolifically during grey sky. Pied imperial-pigeons disappear at the end of the the dry – a common response to wet season, having come to Australia from New Guinea to stress – so they are now producing take advantage of fruiting trees and predator-free offshore fruit in abundance for birds and other islands for nesting. The parent birds take it in turns to visit animals. However, tropical plants the mainland to feed each day, one staying with the egg or flower and produce fruit all year round, chick. In the evening large flocks can be seen winging their otherwise fruit- and nectar-dependent way home. In the past these flocks were truly enormous, but animals would not survive to perform shooting and rainforest clearing have seen a dramatic decline their dispersal and pollination duties. in their numbers with only a few hundred nesting in places Summer rains, therefore, also instigate where once there were up to 100 000. flowering. Golden penda (Xanthostemon chrysanthus) has been observed to flower particularly Metallic starlings, with black iridescent plumage prolifically five weeks after cyclones, although whether and rominent red eyes, dash at breakneck speed rainfall, wind, air pressure or some other factor is responsible from fruiting tree to fruiting tree in exuberant is not clear. flocks, sometimes hurtling low along streets at such speed that pedestrians, cyclists and Insects thrive in response to summer warmth, humidity and drivers alike are inclined to duck and cringe, rain, their rush to breed forming the basis of a flourishing certain they will be hit. These sociable birds food chain which includes frogs, fish, insectivorous bats, birds build colonies of messy, globular nests, often and reptiles in its links. dangling by the hundred from street trees. Their lively comings and goings and noisy chattering A shower on a humid evening may inspire winged termites to are a prominent feature of summer in the tropics. spill out from their nests. Appearing in sudden , most Although most starlings return to New Guinea by April, some of these sexually active adults have a limited future. Birds can be seen in the wet tropics through much of the winter. wheel and swoop, darting at the winged bonanza. Those These may be juvenile birds, or they may be starlings which termites which escape lose their wings when they fall to the nest further south and as part of the northwards migration fly ground but, if they are able to mate, may establish a new only as far as the wet tropics for winter. colony. Buff-breasted paradise-kingfishers fly to Beetles, their development from larvae from New Guinea to raise their young on the insects, accelerated by summery conditions, frogs, lizards and snails which suddenly become become suddenly abundant at the bountiful in the wet season. beginning of the wet season. The timing of their appearance has led to many being called Christmas Heavy rains can cause subterranean creatures to make an beetles, but this title belongs not to one species but to unexpected appearance above ground. Blind snakes (see p3) several, each area having its own ‘Christmas beetle’. and worms slide out of their flooded burrows to avoid drowning. Walkers in upland rainforests may come across Flower scarabs are particularly noticeable as they fly by day, the extraordinary Queensland blue worm which can grow buzzing in large numbers around blossoming plants. Having to 60cm with a 2cm diameter, although there are reports of spent years living below ground, cicada larvae respond to some individuals reaching two metres in length. It varies in warm humid weather by climbing up vertical supports and colour from turquoise to grey-blue. splitting out of their skins as winged adults. Summer days can be dominated by the deafening Whistling spiders are also forced out of their burrows by sound of singing males. They can flooding and may wander into houses to give the occupants a only perform if the air temperature fright. Australia’s largest spiders, they is high enough and fall silent when it normally stay out of sight during the drops below a certain level. day in metredeep silk-lined burrows. Although their bite is not considered life- Some birds visit the wet tropics only threatening, it can be painful and cause at this time of year, to breed. sickness.

Tropical Topics updated 2011 Nature notes

A diary of natural events creates a pleasing journal which grows richer with the passage of time. Watching for the recurrence of an event after noting it in a previous year, and trying to understand what could have caused changes in timing, is intriguing.

The moth become more common In spring and summer orchid during the first part of the year as the tasty red fruit can (Phalaenopsis flush of plant growth feeds increasing be found on native amabilis) numbers of caterpillars. raspberry bushes produces (Rubus spp). This plant its beautiful Green spotted often takes the form of flowers during triangle a scrambling shrub, its the wet season, butterflies branches from about are most covered with small December to frequently seen thorns, and tends to grow April. Borne from January to in disturbed forests and densely May. This is roadsides. White flowers are on a long, a tropical followed by the raspberries arching , which are popular with birds. The stem, each found only leaves often have a metallic, bronze flower measures up to 8cm north of sheen on the underside. Several across. The broad, flat petals, which Mackay to the species are native to Australia but one are thought to resemble a moth’s wings, Torres Strait in Australia. It also import, Rubus alceifolius, from south- are pure white with a little yellow on lives in New Guinea and in south- east Asia, has been declared a weed the lip. Large, pendulous leaves are east Asia, through to . Living mainly due to its aggressive lantana-like growth fleshy and able to store water and in the rainforest, this butterfly flies with habit and tendency to choke tracks and nutrients for the plant. a distinctive rapid, nervous manner, rainforest edges. pausing for only a moment to sip nectar These orchids from a flower before fluttering off again. The call of the noisy pitta is seen as are epiphytes, Male and female look alike, their black heralding rain. Sounding like a growing wings heavily marked with bright green. questioning ‘walk-to-work?’, the call is in partial The lower surfaces are duller, with some usually repeated twice, pairs using it to shade on red spots. Caterpillars feed on a number keep in contact in the dense forest. This the lower of plants in the Annonaceae family, call is the best indication that these branches of notably fairies basket (Pseuduvaria lovely birds are around, although they rainforest trees froggattii) as well as cultivated custard fall silent after the breeding season. In and sometimes, as apple and sour sop trees. spite of their quite colourful plumage lithophytes, on rocks in they are very unobtrusive as they areas of high rainfall. They Toxic fruits of Queensland walnut, also fossick around the forest floor in are found in lowland rainforests and on known as the black walnut (Endiandra search of invertebrates. Piles of empty lower slopes in the wet tropics as well palmerstonii) ripen between December snail shells are an indication of pitta as at Iron Range and the McIlwraith and April. This large tree, with a presence, the birds bashing them open Range of Cape York Peninsula and in spreading canopy, grows in lowland and on favourite stones or pieces of wood. New Guinea. upland rainforests between Tully and Pairs nest during the early wet season, Cairns and produces excellent timber. building a domed construction usually The fruits, which are about 6cm across, on the ground and often in the are green to red and ribbed. They buttresses of trees. Sometimes a patch contain a large seed which, although of moist mammal dung, collected by the poisonous, is an important birds, forms an entrance mat and may traditional Aboriginal food. After serve to disguise correct processing and cooking the smell of the it is said to taste like bread. The chicks from ground seeds could also be used predators. to lure brushturkeys for capture.

Tropical Topics updated 2011