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Friday, 12 April 2013

One of these things, not like the other echidnas

I have taken on a new interest, having joined the Nursery Group at the Sydney Harbour Trust's North Head Sanctuary.  These people are volunteers from the Manly area, and they are experimenting with raising seeds and cuttings of local plants to do bush regeneration.

I used to teach at a school not far from there, but while I had taken a census of more than 50 birds passing over, and while I knew there were bandicoots (a small marsupial) which were somewhat endangered, I was unaware of some of the other life that was around.

I went to a lecture at the old Quarantine Station, where Geoff Lambert told a crowded hall about the plants of North Head.  I would have guessed there were about a hundred, perhaps 200 species on the headland, but in fact there are more than 400, and the Nursery Group is working to maintain the rarer and more at-risk plants.

It seemed like fun, and getting the hands dirty would offer a good sorbet from writing, so Chris and I joined up.

One of the main tasks is planting suitable habitat on large open areas like an old oval that the Army had there: in all, there are something like 80 sites that they are working on.  Others have other pursuits, and I discovered, after seeing an echidna there, that there is a known population, and Geoff Lambert is collecting photos of the different animals, to try to assess the population size.

Today, I saw this one, which is a juvenile, Geoff knows it well, because it is very tame. He says it is about 800 grams and he guesses about 8-10 months old.  He has lots of shots, so he had no need of the thirty or so that I had taken.

When I got home, I decided to compare it with shots I have taken at other times.

Two echidnas: left, from the Hume Highway, just north of Albury in NSW, 
right, from north-western Tasmania, which is colder.
Echidnas are, like the platypus, generally referred to in the text-books as egg-laying mammals, though you can make almost as good a case for them being warm-blooded reptiles.  Proving that hinges on some desperately fine technical points about the coracoid, the embryology of the egg, locomotion and the venom of the male platypus, so just take my word for it.

One of the more reptilian characteristics is that they are not as homoiothermic as mammals like us or marsupials.  So it is significant that the Tasmanian echidnas, coming from a colder climate have more fur and fewer needles (those needles, by the way, are modified hairs).

Anyhow, I thought that was interesting enough to share.  I'm sure there is, or has been, a research project on that at some stage.

Here are some more shots that are of that same young echidna, and then, from the morning tea table a few minutes later, something that may bear a small resemblance to the echidna, but a leg count will rule it out of contention for a place at the next Monotreme Family Reunion.

The beastie on the right is, in fact, a beetle, or to be more precise, an adult weevil.

And in case you are wondering, neither the weevil nor the echidna is related in any way to the elephant.


My good friend Jan Pittman has just shared with me an echidna from their garden in the outer parts of Perth in Western Australia, and kindly given me permission to share it here.  Now I need to get examples from Queensland and South Australia—and probably from Kangaroo Island as well. There would definitely seem to be the makings of a science project here!

Mind you, I am beginning to wonder if the Tasmanian specimen may have been a juvenile whose spines were still growing. A sample of one is too small to hang a theory on!

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