Tropical Topics A n i n t e r p r e t i v e n e w s l e t t e r f o r t h e t o u r i s m i n d u s t r y
Forest fruit dispersal No. 35 April 1996 Unexpected dispersers Notes from the Wind, gravity and water can move seeds away from the parent plant, but a very high percentage of rainforest species employ animals, paying them with a Editor dispensable fruit layer for their seed dispersal services. Writing some of this issue at home, I was frequently distracted by the While the plant is prepared to supply a tree could hardly wish for a better fate squawking of metallic starlings certain degree of nutrition in this fruity for its offspring. feeding on the fruits of the buttonwood packaging, it invests the lion’s share tree in my garden. Closer to the window, of nutrients in its seeds for the benefit Unfortunately for the seeds, white- preparations are in hand for the of the next generation. Many of these tailed rats are good at finding the October fruit feast, as buds appear on seeds are protected by a hard shell — buried seeds. Perhaps they can smell the corky bark tree. but a number of rainforest animals them or perhaps they remember where have realised that it is worth the effort they buried them — no one knows. Of In temperate climates there is an of penetrating this defence. 1244 seeds whose fate was followed autumn glut of fruit but animals must by CSIRO researchers, 20 percent were include other foods in their diets if Giant white-tailed rats are among the hidden but all were eventually eaten. they are to survive the rest of the year. most voracious of these, using their However, although none of the seeds In the tropics fruit is produced all year exceedingly strong teeth to break into studied ever got a chance to and as a consequence there are many even the hardest nuts. Given the sheer germinate, one remained uneaten for animals, particularly birds, which eat numbers of rats in the rainforests* and 20 weeks which would have been long nothing, or little, else. the thoroughness of their seed enough for seeds of many species to predation (see below) it is actually sprout and grow. It would appear that Since so many animals depend on surprising that any of their favourite one seed, carefully buried and then these fruits and so many trees depend trees survive. forgotten, probably makes up for the on the animals, it is a good idea to help multitudes that are sacrificed for the keep the cycle going by planting those cause. native trees which provide food. You However, it seems that white-tailed can find a list of some on page 7. rats have a habit which works in the trees’ favour. They hide I would like to thank the following seeds. Perhaps they are people for their assistance with this unable to eat all of what they issue: Andrew Dennis, JCU; Stephen find and hide them rather Comport, CSIRO; Graham Harrington, than share them with CSIRO; Bernie Hyland, CSIRO; others or perhaps they Rosemary Lott, JCU; Mike Trenerry, are looking ahead to DoE. lean times. Whatever the Please note reason, this results in that you are welcome to photocopy seeds being taken from Tropical Topics. However, if the below their parent tree, text is reproduced separately it must carried up to 60m away, not be altered and must buried, singly, at a depth of acknowledge the Department of 1-2cm and covered with Environment as the source. lightly compressed soil and a Illustrations must not be reused layer of leaf litter. The parent without permission. Please contact the editor (details on the back page) *Of 10 000 small ground mammals trapped over if in doubt. the past ten years by William Laurance, CSIRO, 98 percent were rats. Quality or quantity? When producing fruits to attract animals, plants have a number of options. One plant may produce a large number of small ‘poor quality’ fruits while another opts for a smaller number of ‘top quality’ fruits.
Lilly pillies (Syzygium spp.) are in the former Figbirds love celerywood group. They produce abundant crops of (Polyscias small fruits which are high in water and elegans) sugar content and thus ‘cheap’ to produce (in terms of energy and resources used). Not particularly high in nutrients, they may be a Wompoo pigeon at its nest snack for those animals which include fruits in a mixed diet — but the plant is taking a risk. A number of the consumers are likely to also be seed eaters or to Feeding the youngsters have grinding gizzards which would also destroy ingested seeds. A significant Most animals which eat fruit have to proportion of the seeds from these plants are certain to be doomed. supplement their diet with insects, nectar, pollen and so on. Cassowaries Fruits in the second group, such as some of those in the Lauraceae family, are are known to sometimes eat snails, particularly sought after by those animals which depend on fruit. They need a insects, fungi, flowers and dead more nutritious diet and are offered fruits with a higher content of protein, fat and animals. Only a few animals, mainly oil. Requiring more of the plant’s energy for production, fewer are produced, but birds which can easily move as their consumers, such as cassowaries and fruit pigeons*, are less likely to supplies fluctuate, eat nothing but destroy the seeds. fruit.
Fruits in the second category are likely to have a large seed, When raising young, which require perhaps encased in a hard shell. The large seed has less protein to develop, mammals are able chance of being carried far from the parent plant than a to provide protein-rich milk. Birds do small one, but is more likely to produce a strong sapling. not have mammary glands — but those strict frugivores, the fruit *Not all fruit pigeons are soft on seeds. Some, notably the brown cuckoo-dove, have stones in their gizzards and can reduce the pigeons, are able to produce a milk-like seeds of the fruits they eat to a paste. The hairy walnut substance in their crops to feed to (Endiandra insignis), a their chicks. Other fruit-eating birds, nutritious Lauraceae unable to perform this feat, may break fruit . with their vegetarianism and give Fatal attractions insects to their chicks, even if only for Just because cassowaries and other birds, or even mammals like rats, a few days. can eat rainforest fruits, it does not mean that we can also. A very large proportion are very poisonous so please remember — the bright attractive colours are strictly for the birds (and some non- The fruitfly connection human mammals). When the papaya fruit fly was found in north Queensland there were fears that it would spread into Coming attractions the forests of the wet tropics so, in Plants do not want their fruit to be picked before it is ripe. To prevent this some January, DPI staff began a are covered with spines, others lack the attractive scent of the ripe version and rainforest trapping program. They many are colour-coded. Greens and browns camouflage unripe fruits which may plan to continue until the end of turn to red, yellow, black or blue when ripe to advertise their readiness for May to cover the peak of the plucking. It has been said that it is the fruits of the rainforest, rather than the fruiting season. flowers, which produce many of its most vivid colours. A total of 148 traps have been A familiar strategy for rainforest plants is to conceal their seeds in a dull coloured placed in rainforest sites from Noah capsule which splits open when ripe to display a bright red or orange interior with Creek, near Cape Tribulation, to contrasting black seeds or seeds with colourful arils. Josephine Falls and East Palmerston. Happily, very few papaya fruit flies have been found in these traps, most of them in traps located close to roads at Lake Morris, Kuranda and Rex Range. No breeding populations were found. Even better, of 3000 rainforest fruit samples collected Peanut tree none contained the fruit fly. It (Sterculia appears that the flies are attracted quadrifida) primarily to commercial fruits, where pods have a they are much more easily The dull green fruits greenish-brown controlled. of McIntyre’s boxwood exterior but split (Xanthophyllum octandrum) open to reveal a Unfortunately the feral flies are split open when ripe. The bright strongly coloured attracted to the equally feral guava yellow inner lining thus revealed puts orange to vermilion interior, trees which grow in the wild. DPI the black seed on display for the contrasting with half a dozen shiny staff are targetting the trees with a birds. black seeds. herbicide program.
2 Out and about
The Great Barrier Reef Marine Park Information Manual, and associated videos, have been produced by Over the past GBRMPA and will be available very few weeks soon. residents of Cairns have been treated The manual is in four components. The showy to the unusual sight Reef Essentials provides a basic fruit of cherry of spectacled flying understanding of how the World beech (Ternstroemia foxes circling around in Heritage Area is managed and how to cherryi) can be seen at this time daylight. Unable to conduct activities in the most of year. Yellow oval fruits split open resist the tempting scent of environmentally responsible manner. It when ripe allowing seeds clothed in their favourite food, melaleuca nectar, is accompanied by a 60min. video. Reef bright pink-red arils to dangle out and the bats are throwing caution to the Understandings is about the ecology attract the attention of passing birds. wind and taking their chances with and biology of the Reef and has an falcons and sea eagles which could associated 1hr 30min. video. Reef attack them. Melaleuca trees put on Communication deals with skills and two courses of nectar, a daytime feast ideas needed to effectively for honeyeaters and other birds and a communicate information and Reef nocturnal one for bats and moths. Learning Guide outlines the main Efficient pollinators as well as fruit concepts in the manual as a whole. dispersers, the bats reward the melaleucas by fertilising their flowers. A copy of the kit will be mailed to each permitted tour operator in the GBRMP and additional copies will soon be available from GBRMPA. Tel: (077) 500 Mastering the Tropical Environment 700 for details. The Tropical Environment Vacation School is providing professional development courses for resource managers, academic staff and industry April is usually wattle-blossom personnel. Three intensive training time for several species found in courses on contemporary planning the wet tropics. Flowers can be and management of Australia’s expected from brown salwood or tropical coast will be held at sally wattle, northern wattle and Hickory wattle (A. Townsville’s James Cook University hickory wattle. These three are aulacocarpa) has slightly this year. Each 10-day course is run by common species along rainforest twisted pods, the outer leaders in their field and involves margins and in exposed situations surface of which is distinctly extensive lectures, case study such as beaches, steep ridges sculpted with a series of fine lines. workshops and tutorials. and large gaps within rainforest. Environmental law in the tropics Northern wattle ( Acacia Coordinator: Peter James crassicarpa) is easily Brown salwood ( A. mangium) Dates: 24 May-3 June 1996 recognised because develops tightly coiled seed pods. Venue: JCU Cairns campus of its very broad, About the middle of the year Cost: $1000 flat pods. sulphur-crested cockatoos will be extracting seeds from these Integrated coastal management: pods, littering the earth with Ecologically sustainable use of their leftovers. Australia’s coastal zone Coordinator: Richard Kenchington Dates: 8-19 July 1996 Venue: JCU Townsville campus Cost: $1000
Please note that permits are required Caring for country: Recognition of for commercial activities carried out on indigenous people’s interests in conservation parks and resources managing Australia’s tropical reserves as well as national parks. environments Local examples of these include Coordinator: Dermot Smyth Mount Whitfield Conservation Park, Dates: 9-20 July 1996 Cairns, Jumrum Creek Conservation Venue: JCU Townsville campus with a Park, Kuranda, Malanda Falls field trip to Aboriginal communities Conservation Park, Keatings Lagoon Cost: $1000 Conservation Park near Cooktown, Chillagoe (Smelter) Resources For further information and bookings Reserve, Heathlands Resources contact Tropical Environmental Reserve, Iron Range Resources Studies and Geography, JCU, Reserve, Jardine River Resources Townsville, Tel: (077) 81 4325; Reserve, and Palmer River Goldfields Fax (077) 81 5581. Resources Reserve.
3 Agents of dispersal Just as we expect grown children to leave home and produce their families at some distance from us, so also a parent tree strives to prevent its seedlings from growing up under its feet. It is better for the saplings to take their competition for soil nutrients, water and light elsewhere. Movement for a stationary tree, however, requires an agent. About 40 species of rainforest birds Flying foxes are very important seed dispersers (as well eat fruit as a major part of their as pollinators). They visit tree tops and can fly up to diet. The most important of 50km in one night carrying seeds at least part of the way these as far as dispersal is with them. Their narrow gullets allow only seeds under concerned are the pigeons; 4mm in diameter to be swallowed. Most fruit is squashed Australia has a particularly between the tongue and the ridged palate, the juice large number of pigeon swallowed and the pulp and intact seeds spat out. Large fruits species (which perhaps are often carried some distance, the fruit consumed and seeds compensates for the lack of dropped elsewhere. those important dispersal agents found in most other The greater the number of flying foxes seeking fruit from a tree the tropical forests — monkeys and better it is for the tree since those for which there is no apes). room on the branches may perform daring raids, snatching fruit and carrying it some distance before feeding Fruits which attract birds are usually — and depositing the seed. Some are dropped in brightly coloured and frequently employ flight thus introducing saplings to cleared areas. contrasting combinations of red, yellow and The same good fortune awaits small seeds which black when ripe. Small fruits may be swallowed were ingested as they are also defecated while the whole and the seeds passed through the animal is flying. This puts these seeds at an bird’s digestive system, ideally intact, but advantage over those eaten by birds which are often birds regurgitate the seeds from their usually dropped from perches in crops, spitting them out rather than allowing Fruits which appeal to bats trees, not in open areas. tend to be pale brown, green them to pass right through. Otherwise the or yellow, like this pale The Queensland tube- fleshy fruit, or an attractive covering around yellow pencil cedar nosed bat feeds on fruit the seed called the aril, is eaten and the seed (Palaquium galactoxylum). and is known to disperse discarded without being swallowed. whole fruits, such as figs.
When the dull green capsules of Over 1500 Australian plant species produce seeds with a small appendage called the fire vine (Tetracera an elaiosome. This part of the seed is rich in fats and attracts ants. They nordtiana) are ripe they split carry the seed back to their nests where they feed the elaiosomes to open to release bright red their larvae before discarding the seed — which is to all intents filigreed discs (arils) in the and purposes neatly planted in a nutrient-rich environment (the centre of which are shiny black ants’ waste heap) at a distance from the parent plant and out of seeds, the size of a matchhead. sight of seed predators. This is particularly common among The red attracts birds, particularly plants in dry areas but also in acacias in disturbed rainforest metallic starlings, which devour the areas. aril, rejecting the seed. Evidence is emerging from research done by JCU student Andrew Dennis that musky rat-kangaroos may be extremely important seed dispersers. These little The parents of seeds larger than a plum are in marsupials feed primarily on fruits and seeds of rainforest plants, as well as trouble when it comes to getting their progeny invertebrates and mushrooms. The fruits they eat range from tiny ones to those to leave home. No birds are able to move such weighing 100g. Sometimes only the flesh is eaten and sometimes the seed as well. large seeds — apart from one giant, the cassowary. Sometimes called an ‘honorary Musky rat-kangaroos do not like to share their food so, if another one appears at a mammal’ for a lifestyle which scarcely resembles fruit-fall, the first animal will usually pick up a fruit and run away to feed. In cases that of a bird, the cassowary eats the fruits of where only the flesh is eaten, the seed is dropped, in the leaf litter, away from the over 70 rainforest trees. Its gentle digestive parent plant where it has a greater chance of survival. This process is likely to system passes the seeds, unharmed and often happen a number of times at a fruit-fall. with flesh still attached, into what is, in effect, a pile of compost. While keeping the seeds moist, Like white-tailed rats, musky rat-kangaroos also scatterhoard — they take single it is thought that this compost also protects the fruits and seeds and hide them at different locations throughout the forest in seeds from predators such as the white-tailed buttresses, under logs, in the leaf litter or buried in the soil so that competitors — rat. It is also thought that something in the including rats — are unlikely to find them. cassowary’s digestive system stimulates germination of certain seeds. As with those hidden by white-tailed rats, some fruits and seeds are eventually overlooked and are well-placed to germinate. Cassowaries numbers are decreasing in the wild However, in contrast to the white-tailed rats, as they lose vital habitat. even when the musky rat-kangaroos do Unfortunately, as they return to recover their booty, they may eat disappear we lose only the flesh of the fruit, dropping the a very intact seed. Musky rat-kangaroos are important thus important dispersers for forest agent of fruits and may indeed handle as many distribution. species as the cassowary.
4 A number of large trees, Various ‘oaks’, such as this particularly high canopy and northern silky oak (Cardwellia emergent trees rely on wind for sublimis) produce dispersal. woody capsules which split open to The woody cones of brush free the light cyprus pine (Callitris flattened seeds macleayana) (left) within. Wind- contain winged seeds. dispersed seeds tend to Sulphur-crested be brown or grey, cockatoos consume large resembling dead plant numbers of them but allow tissue and presumably Parrots, others to escape on wind avoiding the attention of particulary sulphur- currents. predators. crested cockatoos, destroy a great number of seeds with their strong The spore-like seeds of orchids and beaks. However, being messy eaters, epiphyte ferns are so light they can be they may unintentionally help the carried aloft by the lightest breeze to treetop plants by dropping a proportion of branches where new plants can develop. the seeds and knocking fruits to the ground where cassowaries and Some rainforest trees produce huge seeds which other forest floor animals pick them are too big for even a cassowary to tackle. up and continue the dispersal Ribbonwood (Idiospermum australiense) is a rare process. tree found only in small areas of the wet tropics. With a fruit the size of a billiard ball and a seed Seeds of red tulip oak (Argyrodendron which is highly toxic to mammals (except peralatum) are wind bourne. for musky rat-kangaroos), currently its only option for dispersal is gravity. There is no way this plant can, naturally, now Recent floods would have done some move uphill! Perhaps, in the distant past, plants a favour by moving their seeds it had an animal disperser. Since the fruit Although to suitable spots for germination and would have to be swallowed whole to they feed growth. Some fruits are destroyed by remain viable, it has been postulated that mainly on immersion in water but others are its primitive disperser (if it had one) leaves, buoyant. Many seaside plants, would have been as big as a five-tonne possums, including mangroves, seek water truck! particularly transport (see Tropical Topics 26) brushtails, but some rainforest trees, particularly Without human intervention, sometimes take those which thrive along riverbanks, ribbonwood will eventually have advantage of the such as creek satinash (Syzygium nowhere to go except the sea — and fruit on offer and can australe) also use this as one of their extinction. This illustrates the problem carry large ones, even the size options. Seeds of the blue quandong faced by many plants if their disperser (or of an apple. Bad-tasting fruits (Elaeocarpus angustifolius) and pollinator) disappears. We still know little about may also benefit from possum black bean the intricacies of these relationships. It is likely distribution, being spat out (Castanospermum that certain seeds could not germinate if a when the animal discovers how australe) float well and particular animal is not able to remove an aril or unpleasant they are! survive periods in crack a hard shell or remove a germination water. inhibitor. Then, slowly but surely, the forest Tree-kangaroos too may act as Blue quandong composition would be irreversibly changed. part-time agents.
Black bean Apart from their role as seed predators and dispersers (see page 1), white-tailed rats also perform a very important function by spreading the spores of certain mycorrhizal fungi. In common with northern bettongs, they dig up and eat the underground fruiting bodies, the truffles, dispersing the spores in their faeces. These fungi form important symbiotic relationships with both rainforest and sclerophyll trees. They attach themselves to the roots and, in return for sugars extracted from the trees, transfer nutrients and water from the soil to their hosts. Some tree species are unable to survive without these fungi so the rats’ role in dispersing the spores is an important contribution to the forest’s wellbeing. Other rodents also feed on fruits. Bush rats have been observed carrying large fruits, such as figs, to ‘feeding tables’ where they are eaten over a few days, some seeds being left intact. They are also thought to hide and store seeds. Melomys also feed on rainforest fruits.
5 Questions & Answers Facts and Stats About 80 percent of Australian Q What is the latest on the declining in water, it would explain why stream- rainforest trees produce fleshy fruits frogs of the wet tropics? dwelling frogs, which breed in water, attractive to vertebrates, a much higher have been the only species affected. It percentage than in other vegetation types. A Seven wet tropics frog species have could also possibly be spread by Rainforests have a correspondingly declined since the mid-1980s. Four of mosquitoes or black flies which bite higher percentage of fruit-eating these appear to be extinct and three frogs and move between catchments. animals. species remain only in lower altitude However, the big problem with the fringes of their former distributions. virus theory is that none has been Some animals, such as squirrels, The declines have moved through isolated from the dead frogs analysed. larderhoard, storing nuts in one place. Queensland in a wave, at a rate of 100km Scatterhoarding animals hide the food per year on average, from south to One common feature of those frogs items singly, in different places. north. In some cases frogs which were which have disappeared is that they abundant vanished in only one season. produce only low numbers of eggs. If Mace, the spice, is the aril from around hit by a disease they would be likely to the nutmeg nut. Both of these are Despite the efforts of a number of take much longer to recover their encased in a capsule which splits open scientists to either rediscover the frogs numbers than the more fecund species. when ripe. Sometimes native nutmegs, or discover the reason for their Possibly the problem is a combination with a scarlet filigreed mace, are seen disappearance, there have been no of effects — perhaps pollution carried on the rainforest floor. Curiously, the dramatic breakthroughs. In November in rainfall weakens a population which edible part of the lychee is also an aril. and December 1994, 39 people combed is then devastated by a disease it would Thornton Peak — without success. In normally be better able to resist, the The eggs of many stick insect species June 1995 searchers were lifted into a low numbers of eggs produced resemble seeds with a nutrient-rich remote part of the North Johnstone preventing it from making a recovery. elaiosome-like appendage attached (see River, west of Innisfail, hoping to find p4). This attracts ants and, like the seeds, some traces of the frogs in a pristine Scientists are continuing their research. the eggs are carried to the nest, stripped area remote from human contact — but If there are any breakthroughs, we will of their food packages and left found none. Bellenden Ker and Bartle let you know. underground in peace and safety to hatch, Frere have similarly been scoured a process which sometimes takes years. without result. Q Do fish vocalise? The teeth of white-tailed rats are strong A number of theories for the A Many fish are not silent. Angelfish enough to open tin cans and rainforest disappearances have been suggested. have been heard to thump loudly and residents swear that these rodents can Glyphosate herbicides are known to kill certain damsels make chirping noises read the labels. A favourite is condensed frogs and tadpoles but pollutants such to communicate. Sweetlips are also milk. One rat was observed to unscrew as these are less likely to affect pristine sometimes known as grunts because the lid of a jar of jam. upland habitats, the scene of the of the grinding noise made by the teeth disappearances, than the lowlands, in their throat and amplified by their Mistletoe fruits are extremely sticky and where some species still survive. An swim bladders. Jewfish are known as remain so after they have passed through increase in ultraviolet rays, due to holes croakers in America because of the the mistletoe bird — a process which in the ozone layer, sounds like a good sound created by them drumming their takes only about half an hour from beak theory — but most of the declining swim bladders and toadfish are to bottom. The voided seed remains stuck frogs are nocturnal, hiding away during presumably named for the resemblance by a gluey thread to the bird which has the day, and in any case the ozone hole of their mating calls to those of toads developed a characteristic dance to wipe affects temperate, not tropical latitudes. and frogs. Dwellers in houseboats on it off on to a branch — exactly where the the coast of the United States are kept mistletoe seed needs to be. The A favourite theory is that a virus is awake at night by the extremely loud procedure was wonderfully captured on sweeping through frog populations. noises made by one of these species, film for the recent TV series Secret Life of One which cannot survive in the warmer the oyster toadfish. More locally, our Plants. A small mistletoe plant has been temperatures of the lowlands would noisy fish include saltwater grunters, photographed sprouting on a telephone explain why only upland frogs have trumpeters and freshwater blackbream. line, presumably wiped off there by a been affected. If this virus was spread mistletoe bird.
Feral pigs, for all their faults including seed predation, may be distributors for some large-fruited forest plants -— although this includes the terrible weed, Tourist talk pond apple (Annona glabra). ENGLISH GERMAN JAPANESE fruit Frucht kajitsu Seed dispersal on the fur or feathers of seed Samen tane animals is rare in rainforest — except for the pisonias (P. umbellifera) (and the disperse verbreiten chirasu seaside P. grandis) which are so sticky white-tailed Weißschwänzige shiro o that birds and even snakes have been rat Ratte nezumi unable to free themselves, sometimes cassowary Casuar hikui dori dying as a result. flying fox Flughund o o koumori bird Vogel tori Plants manipulate animals to disperse their seeds for them — and humans are pigeon Taube hato no exception. We collect fruit and throw wind Wind kaze away or deliberately plant the seeds. We gravity Schwerkraft, juryoku even spread plants because they look Gewicht good!
6 Ancient nuts and modern Plants for wildlife predators Certain plant species are particularly beneficial for wildlife and are ideal for including in gardens and revegetation projects. Some of the best are listed below — but this is by no means a comprehensive list. Acknowledgements to Mike Trenerry, Dept Env.
Good Nectar Fruit Leaves Particularly useful for eaten eaten eaten characteristics are by by by indicated — but please note that this is not the limit of the plant's benefits. Especially useful species Nibbled candlenuts (Aleurites are marked *.
moluccana) (above) and lowlands uplands birds fruit bats insects birds fruit bats possums caterpillars other animals Queensland macadamia nuts Pandanus species ( ) are a sign Macadamia whelanii (P. tectorcoris/whitei/soms-lobachii) Nesting sites of crimson finch of white-tailed rat activity in the forest. Native passionfruit vine * (Adenia heterophylla) *Red lacewing, orange cruiser, glasswing *White mulberry * * In 1961, CSIRO botanist Dr Bernie Hyland collected (Pipturus argenteus) *White nymph *Giant spiny stick insect some mysterious nuts in the Bartle Frere area. They *Corky bark * remained unindentified until 1994 when it was (Caralia brachiata) *Four o'clock moth noticed that they resembled an old drawing of fossil nuts Fig species (1 Ficus racemora/ 1 2 * * 2 which had been set in rock 50-60 million years ago. They 1opposita/ leptoclada/ pleurocarpa 2 ) *Green ringtail *Red-legged pademelon were identified as belonging to Eidothea zoexylocarya, a *Pink euodia pademelons * primitive member of the Proteaceae family. (Melicope elleryana) *Ulysses butterfly host plant Alexandra palm Since the fossils came from central Victoria, this tree was (Archontophoenix alexandrae) obviously once widespread — in the days when rainforest Dutchman’s pipe vine * covered much of the continent. Now, however, it is rare; it (native Aristolochia) *Cairns birdw'g, red-bodied swallowtail, big greasy has been found only in five small groups within the wet *Damson trees tropics. (Terminalia sericocarpa/meulleri) Large volumes of fruit *Paperbarks Interestingly, the majority of the nuts from the living trees (Melaleuca leucodendra/dealbata) Large amounts of nectar have been opened and the seed stolen, presumably by rats. Fish poison tree The fossil nuts, however, were intact. Conditions which led (Barringtonia racemosa) to their fossilisation, for example being buried in silt during a Trema orientalis * * flood, may have prevented any predators from reaching *Moth caterpillars *Grasshoppers, crickets, stick insects, beetles them but it is also likely to be due to the lack of rodents in Quandongs (Elaeocarpus spp) 2 Australia at that time. They are certainly comparatively new * (E. angustifolius/ 2 ruminatus/ 2 largiflorens) *Herbert R. ringtail, lemuroid arrivals; the oldest fossil rodents found in this region were Gum trees no more than 4.5 million years old. * (Eucalyptus spp.)*Many insects; trees are good mistletoe hosts It is difficult to tell if predation by rats is the reason for the Umbrella tree * restricted distribution of this tree. After all, although most of (Schefflera spp.) *Tree-kangaroos (both species) the candlenuts found on the forest floor have been opened Bleeding heart * * and robbed of their seeds by rats, there are still plenty of (Omolanthus novo-guineensis) * Herbert R. ringtail*Hercules moth candlenut tree saplings so this species presumably benefits Lilly pillies/satinashes from the animal’s tendency to scatterhoard — or, at least, is (Syzygium spp.) surviving the predation. Walnuts (Endiandra spp.) * (E. sankeyana/ E. monothyra) *Green ringtail, lemuroid (fruit also) Similarly, despite the scarcity of intact nuts, there are some Walnuts (Beilschmedia spp.) * Eidothea zoexylocarya saplings in the forests, so hopefully (B. bancroftii/ B. oligandra) *Also lemuroid and musky rat-kangaroo this tree too will continue to survive predation. Bollywood * * (Litsea leefeana) *Green ringtail, lemuroid. *Blue triangle Ashes * * Rats as agents of invasionary forces (Alphitonia whitei/petrei) *Green, Herbert R. ringtails *Red-legged pademelon It is thought that white-tailed rats contribute to the Celery top * invasion of wet sclerophyll by rainforest. This process, (Polyscias spp.) *Favourite of Herbert R. ringtail which is diminishing the area of a rare and important Other useful species habitat, is estimated to be proceeding at the rate of 1.25m White beech Black wattle per year. (Gmelina dalrympleana) (Acacia aulacocarpa) Pepperwood Black bean In one experiment Steve Comport, Masters student with (Cinnamomum laubati) (Castanospermum australe) CRC TREM, attached reels of cotton to 50 yellow walnut White cedar (Melia azedarach) Buff beech (Beilschmiedia bancroftii) seeds on the rainforest floor. Nutmeg (Myristica insipida) (Gomphandra australiana) Two of the 50 were carried out of the rainforest and Solitaire palm Acid berries (Acronychia spp.) (Ptychospermum elegans) Native olives buried in neighbouring wet sclerophyll. It would seem Neolitsea dealbata (Chionanthus spp.) that white-tailed rats act as agents for invasionary forces. Laurels (Cryptocarya spp.) Ebony (Diospyros spp.) Oak (Helicia nortoniana) Jitta (Halfordia scleroxyla) 7 Bookshelf Fruits of the Rainforest Australian Rainforests William Cooper and Wendy Cooper Paul Adam GEO Productions Pty Ltd (1994) Oxford University Press
Anyone who is interested in rainforest There is a short section on seed dispersal fruits will fall for this book in a big way! on pages 117-119. William Cooper’s illustrations of the fruits of 626 plant species are Australian Rainforest Plants Vols I-V breathtakingly realistic, even down to Nan and Hugh Nicholson the nibblings of insects on the skin. Terania Rainforest Publishing Most illustrations are life size, often (1990-94) with a cross section, and are accompanied by a short text giving Although not dealing specifically with details of fruit and leaf size (plus leaf fruits, this series of books, with good sketch) fruiting season, distribution photos and text, is very useful for anyone and so on. interested in local plants. Regeneration of large-seeded trees in Growing Australian Tropical Plants Australian rainforest fragments: a Peter and Ann Radke & Garry and Nada study of higher order interactions. Sankowsky G.N. Harrington, A.K.Irvine, Firth and Frith Books (1993) F.H.J.Crome and L.A.Moore In: Tropical Forest Remnants: ecology, Similar in layout and size to the above genetics and management of books, the emphasis here is on gardening fragmented communities with rainforest plants. There are useful Eds W.F. Laurance and R. Bierregaard notes on height and spread, cultivation University of Chicago Press requirements and suitabilities as well as To be published later this year distribution, flowers, fruits, etc.
This was the first study to show that Australian rodents scatterhoard.
This newsletter was produced by the Queensland Department of Environment and Heritage (now The Environmental Protection Agency) with funding from the Wet Tropics Management Authority.
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