Greetings from the Island.

On Tuesday, Peggy presented a Powerpoint lecture about what is known about the Rosenberg goanna, another animal she researches at Pelican Lagoon.  This monitor grows to about a metre or so and is the only goanna on KI.  It is the southernmost living goanna and this makes it unusual for a type of reptile that generally seems to like hotter areas.  This goanna always lays its eggs in termite mounds.  The female works hard for many hours to make a hole into the termites central nursery chamber.  Here it lays up to 12 eggs.  As long as the termite colony is functioning normally the hole in the termite mound will be sealed the same day that the female goanna leaves by the industrious termites.  The termites keep the mound at a range of temperature that they are comfortable with and these temperatures also suit the development of the goanna eggs.  When the small goannas hatch they have a nice larder of fresh termites to eat.  Mike pointed out that these young goannas living in the sealed off mound are breathing an atmosphere mainly composed of carbon dioxide - if that was us we'd suffocate!

[How they do this - go from breathing mainly CO2 and then switch to oxygen when they leave is a great question for  scientists to answer particularly as it appears that the CO2 content of our air will continue to rise in years to  come with consequences we can only guess at.]

After leaving their relatively safe termite mound, Peggy estimates that probably only one of the twelve will survive the predation of native birds like the kurrawongs and magpies. Larger goannas will eat young goannas too and even the eggs if they can find them in a termite mound.

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I had told Peggy and Mike that the Jigalong kids might find it a bit strange that scientist would spend 15 years or more studying a particular animal and probably ask "What for?"  "Whats the good of it?" "Why bother?".

They explained that by taking careful records of how an animal behaves and learning how its body functions, scientists can turn up some amazing facts and often overturn long held ideas and beliefs about an animal.

In the case of the echidna we might also find a way for doctors to perform surgery without  every operation involving anaesthesia (putting people into unconsciousness) is always risky for the patient, they can easily die on the operating table if things go wrong!

I asked them to tell me about this and Peggy told me what she had learnt.  The Echidna is a warm blooded mammal like us but our normal body temperature is 37 degrees Celcius.  Their body temperature ranges from 27 to 31 degrees Celcius and unlike us they can regulate their own body temperature.  When they drop their body temperature their heartbeat slows down, the blood flows more slowly and they consume less energy.  This is a handy trick for echidnas as it means when times are bad and food is short they can just SLOW DOWN and ride it out, without dying.  This must be a great help because the echidna hasn't changed the way it lives or its body shape since the time of the dinosaurs when it first walked the Earth.  And the Earth and its habitats have changed a hell of a lot since then and countless other species of living things have come and gone, but the echidna is still quietly going about its business. And don't forget they can live to 50 years old, which is a lot longer than most mammals!

BUT what does that have to do with people and surgery? --- Well if scientist like Peggy and Mike can work out the body chemistry of an echidna, the hormones etc. that allows it to regulate its temperature, then there might be a way to cause the same effect in humans using new drugs - anaesthesia wouldn't be needed and operations would be a lot safer.

Another possible benefit could be in the area of manned space exploration, where astronauts could be put into a low metabolism state while travelling for years reducing the need for food and water which would have to be taken with them!

These possibilities arise because a couple of scientists get passionate about chasing certain animals around the bush and learning everything they can about them.

SCIENCE AND TRADITIONAL CULTURE - ABORIGINAL PEOPLE

Remember that Aboriginal people have survived for tens of thousands of years due to their study of,and experimentation with, the natural world.  When they hunt, they hunt efficiently using knowledge passed on for generations; when bush medicine is used, again this is the result of knowledge gained by observation and experimentation which has also been passed on.  They just didn't call it science when they looked for solutions to problems in their world and then solved them.

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WORD SEARCH: Torpor, metabolism, hormones, dissection.
 
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FIELD ACTIVITY:  Aim - To recognise that factors like soil water content can

                                       influence where an organism can be found.

                  Equipment - Sealable containers, spade, electronic scale*,                            

                                      evaporation basin*, spirit burner(metho)*, tripod*, mesh mat*,

                                      stopwatch.

             Method  - Collect soil samples from different depths in the same hole, place in

                             sealable containers.  Weigh sample (spoonful) then place in evaporation

                             tray for a set period of time and then reweigh - calculate a moisture     

                             content in weight difference.  
          
         Discussion  - Echidnas dig up insect larvae from the soil to eat. Insect larvae need to

                              prevent their bodies from drying out and some may feed on the roots of

                              plants.  How might soil moisture content of different places in their

                              habitat affect their feeding behaviour?  What factor or factors might

                              influence how moist a soil is?  Is it more efficient for echidnas to be

                              digging down deep to get a feed?

       [ * To be found in the HSBoys store room in the classroom.]

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Today is probably my last opportunity to contact you so I have some more interesting things you can do for the rest of the week.

ACTIVITIES.

On Wednesday, Peggy did dissections on 3 echidnas that had been killed on the roads, I'll tell you the details when I get back - but what you can do in the class, using your experience in the 'gutting' of kangaroos, is to draw a picture featuring different parts of the inside of a kangaroo.  Label your diagram using English and Martu Wangka words.  List the uses if any of these parts. 

Write a letter to Peggy and Mike describing what you have learnt this week about:-

Biologists; echidnas; Rosenberg goannas & Kangaroo Island.

Address: Peggy and Mike

               Pelican Lagoon, Penneshaw

               Kangaroo Island, SA 5222

Bye and see you all on Monday.

PS Check out http://www.echidna.edu.au