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Mackinlaya confusa is a shrub that grows in the understory of the tropical
rainforests of Far North Queensland, Australia. In March 2006, the "Category 5" Cyclone Larry hit us smack on, and the rainforest canopy around Mission Beach was severely smashed, allowing a lot more light than usual to penetrate to the understory layer. The surviving Mackinlaya seedlings were therefore well-placed to take advantage of the opportunity. The seedlings often get to this stage and stagnate for want of light. All the photographs on this web page were taken with flash assistance - the real thing is too dim for natural photographs. There is also a severe contest going on for "root space". You can see that there are three more tree seedlings within 50 cm of our Mackinlaya seedling, and much stronger competition from the bigger trees all around. But with the extra light, this shrub grows rapidly as it doesn't lay down much wood in its stem and won't ever grow more than 3 metres tall. The bendiness of these stems is all part of a plan that has evolved between Mackinlaya and the Cassowary. |
A year after the cyclone, the shrubs were 2 metres tall and coming into flower.
Mackinlaya confusa flower buds
A month later the flowers appear.
Mackinlaya confusa flowering
The stems carrying the flowers are long and fairly stiff, but as the fruits form, the stiffness is overcome by the weight of the developing fruits, until they hang down in a bunch.
The whole plant can be arched over with its load, or if it is lucky, it will be in a sunny spot on the edge of my forest clearing.
Why would a plant produce so much fruit ?
- because it is an opportunist and this is its big chance to reproduce.
"Did someone say fruit ?"
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Enter Billy, a wild Southern Cassowary who has learned that people are not so frightening,
and that some dogs are alright too. He sleeps up on the steep slopes of Mount Douglas,
and comes down to the edge of the wetlands, where I live, to drink and eat during the day. This boldness is not always so good for the birds themselves. They are quite unable to anticipate the speed of traffic or to appreciate the danger they are in when they cross the busy Tully-Mission Beach Road each day. Many are killed by motorists who think the cassowaries should just get out the way or bad luck. That is why there are less than 1,500 of these magnificent creatures left on the planet. Billy likes nothing more than to stand in the creek in the cool shade on a hot spring mid-day. This spot is the last of the fresh water before the creek feeds into the mangroves and brackish water. You need to keep an eye out for crocodiles here. |
 Source : www.burntvillage.com |
The thing on the top of a Cassowary's head is called a casque, and is
a light-weight honeycomb horn structure. The name comes from the medieval French
helmets. I believe its purpose is firstly that it looks good to members of the opposite sex, and secondly that it's like wearing a hat when you go into the forest - it protects your head and eyes from scratches from 'wait-a-while' hooks, Pandanus stabs, Sandpaper Vine scrapes, and so on. These scratches may leave blood and tissue on the hooks that will fester, and then scratch again the next day, causing an infected wound. So it definitely has survival value to stop the top of your head being scratched when you live in the jungle every day. |
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Cassowaries have serious claws on their armour-plated feet, and will kick to defend themselves
or to try and hijack food if people don't promptly hand it over. Consequently they
are not to be encouraged into the built-up environment, where they are likely to meet cars,
silly people, children and dogs that don't know how to behave. My place is isolated and surrounded by a dog fence and the rainforest jungle. It is adjacent to the Hull River National Park. So the day after I took the picture of the mature fruit above, just outside my fence, Billy (who has obviously had his eye on this plant) turns up for a feast. My dog, Jacky, excitedly called me out to watch : |
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[ 3 minutes 40 seconds ] To give you a sense of scale, the fence you can see in the early part is 1.2 metres high ( 4 ft ). As Billy tears more and more fruit off the bunch, the bunch springs up higher and higher, until in the end he has to nearly jump to get the last ones. In fact, though, it turns out to be the 'perfect height', and this is not a coincidence. Lots of rainforest birds would be happy to eat some, but unless you are small and can hang upside down, then they are rather tricky to get at, unless you stand 2 metres tall (on tip-toes). |
Cassowaries have a digestive system evolved to massage the flesh off rainforest fruits, and to pass the seeds and other junk (nuts, seed-pods, twigs, stones, snails) through their gut quickly, say a few hours. In the meantime the cassowary might have walked a kilometre or two, and so the seeds can be spread over a wide area.
Thus the understorey, especially the more open bits, gets a steady supply of seeds, which quickly sprout and then if it is too dark, they wait.
The next day I find this very watery purple cassowary dropping on the track.
The only thing in there apart from the Mackinlaya pulp and seeds is the remains of a Pandanus fruit - that wedge-shaped thing. This one is almost certainly one of last years' crop, that lost its nourishing flesh ages ago. It may even have been eaten by Billy before. [ more on Pandanus species here , more on Pandanus solms-laubachii here ]
Three days later, this dropping shows that Billy has also discovered a source of newly fallen Pandanus fruits - you can see the remains of the yellow flesh left on some pieces. Only one end is fleshy, and after that has been digested, only coarse bristles remain. These will be eaten again for sure - yum.
You can see the Mackinlaya seeds in there. When Billy comes back along this track, he will rake through the dropping with his massive feet, looking for the good bits, and flicking the little seeds around the area.
And look over here, just a few metres away from the dropping is a new Mackinlaya seedling, ready to start the cycle over again.
You might like to visit my Rainforest Photo Catalog where you will also find links to my photo tours of this bio-diversity hot-spot.
Dave Kimble October 2007
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