Sunday, 20 June 2010

Trees and a dinosaur

Its been a little while since my last post so I'm playing a bit of catch-up.  I had a friend visit from the UK so was occupied showing him the mighty sights of Canberra!  Of course, the Botanic Gardens were first on the list and I took plenty of pictures, only I've not had time to write a blog until now (as then we went off for a few days to Byron Bay - great place!)

So, with a visitor to impress I decided to head for probably the most exciting tree in the garden - the Wollemi Pine Wollemia nobilis, the 'dinosaur' tree.  I've just finished reading the book about "the incredible discovery of a living fossil from the age of the dinosaurs" - the Wollemi Pine by James Woodford, which is a great read (I also loved his book 'The Secret Life of Wombats'), so now I know a bit about how amazing this tree is.  Not only is it incredible that the Wollemi pine has survived in such improbable isolation across millennia, only to be discovered in the mid-90s (and only recently available commercially), but its identical genes have baffled scientists, it has unique bark and leaves, even a fungus found on the leaves of some of the wild trees has been found to produce an anti-cancer agent - amazing. To this day, the location of the hidden valley in the Wollemi wilderness near Sydney where the relic trees were found is a secret.
As I proudly showed the tree to my buddy from the UK he smiled and said he had seen one before - in Kew gardens in London!  However, there it is kept in a cage for protection but here in Canberra this amazing tree is just standing quietly beside a side path through the connifer section. 

There are a lot of other fascinating trees in the gardens too, of course.  There is even an aboriginal trail that tells you the aboriginal uses for plants and trees, from which I learnt about the how the aborigines used the hard wood of the Cassaurina or she-oak to make boomerangs, one she-oak boomerang has been found that is 10,000 years old in Wyrie Swamp, South Australia!  Young shoots can be chewed to quench thirst. 

The Bottle tree Brachychiton rupestris is a fascinating tree which hails from Queensland, not only for its very funky shape but also because the wood contains a nutritious jelly which can be obtained to drink by making a hole in the trunk (which can be up to 2m in diameter!). 

There are also hundreds of Eucalyptus trees in the garden, in particular the Brittle gum Eucalyptus mannifera which appears all around the gardens. 

The one above is interesting as a large branch has been chopped off so the inside of the tree can be seen.  Brittle gums are so-called as they may drop branches without warning (so perhaps this one was removed before it dropped), makes me a little more nervous wandering round the gardens now I know that!  This particular tree is also interesting as it is known as the 'Pryor tree', in tribute to Lindsay Pryor who was instrumental in getting funding for the establishment of the gardens.  Below is a photo of the sign that tells more about this tree, including a photo which was taken when the tree had all its branches!

Wednesday, 2 June 2010

An iconic insect of the Australian bush

From my first day in Australia I have become familiar with certain sounds that you'd hear no-where else.  From the distinctive cry of the Pied Currawong Strepera graculina and the Australian Magpie Gymnorhina tibicen to the grating noise of the red wattlebird Anthochaera carunculata and of course the laugh of the Kookaburra Dacelo novaeguineae.   I have found some links to mp3s of these:
The ANBG has a few more calls of birds found in the gardens on its website here.

It is not just birds that make a distinctive noise in Australia, particularly in summer the bush is alive with the sound of insects - its that which really tells me (an Englishwoman) I'm somewhere 'foreign'!  King of these is the Cicada, which although not unique to Australia there are over 200 species of Cicada within Australia found in every corner of the country.  Over the summer we heard these very loudly, particularly when visiting Kangaroo Valley over Christmas where the noise they made was incredibly loud.

This is a sound file recorded in New Zealand of a Cicada - just imagine it multiplied by 1,000 and 10 x louder and you have the Australian bush in summer!

However, until now, I've not managed to see one of these large insects despite feeling surrounded by thousands at times.  At lunchtime I was walking down a less well-trod path in the gardens and at eye level I spotted a very strange looking insect, over 1 inch long.

 I quickly realised it was just a dry shell, the insect having undergone molt from the final nymphal instar to become an adult. The nymph would have been living underground then constructed an exit tunnel to the surface and emerged. Having climbed onto the tree where I found the shell (a wattle-leaved peppermint tree Eucalyptus acaciiformis) the nymph would have split open the shell and flown away, leaving the skin behind clinging to the tree bark like a ghost.  You can clearly see where the shell has been split in my photo.  Here is a film of this event that I have taken from Wikipedia, it looks like an alien!