Saturday, 7 July 2012

Colour and a trip to the rainforest

On Tuesday 3rd July I was lucky enough to have to opportunity to join the local Birdlife Southern Highlands group. We visited a private property in Robertson that has a large area of isolated rainforest. This trip was particularly appealing to me, having spent a bit of time exploring the rainforests of far north QLD. The owners had compiled a great list of birds they had sighted on the property, mostly from the kitchen window!

The tour started along the edge of the rainforest. The first birds of the day were thornbills that were flitting around in the canopy. Right at the very edge however, a small flock of white-browed scrub wrens were spotted. These caused a bit of controversy at the time as their breasts were quite an olive/yellowy-green (I will come back to this later). We moved up into the rainforest where someone had constructed excellent paths, well signposted, in a circular walk. The rainforest is growing in a substrate of chunks of angular basalt chunks and rich volcanic red soil (which is wonderful for growing things in, particularly the potatoes for which Robertson is famous). The owners had organised a botanist to come through and several plant species were labelled. The largest trees appeared to be a Lillipilli variety, Acmena smithii , which have beautiful magenta berries when in fruit. Many of the trees were host to ferny epiphytes, and mosses.    

It was very cool under the canopy, but surprisingly moist for such a cool climate forest. As anyone knows who has tried bird watching in rainforest, it's dark. This is not good for spotting birds. However, one of the highly seasoned bird lovers spotted something dashing across the leaf litter and exclaimed 'a Bassian thrush!' Binoculars were hastily raised and confirmation of the sighting occurred in a split second. Bassian thrush are quite hard to see, and considering it is brown and speckled it is a miracle that it was seen at all in the dimly lit forest. The other lovely thing of note was a bower. It belongs to the Satin bower bird. Related to cat birds, bower birds are all a striking greeny olive, until at around 7 years the males turn a dark satiny blue, hence their name. We have one living in the garden, called Boris. They tend to raid vege gardens and are particularly fond of leafy vegetables. Bowers are constructed as a display area for the males to entice a mate. They decorate them with blue objects such as milk bottle tops, pegs, straws, and blue flowers. Rival males will destroy each other's bowers and steal items from them.
The small pile of twigs on the left is what is left of the bower structure.

We emerged from the rainforest after stopping part way to admire a spectacular view down to pigeon house mountain. Down into the garden and past some gorgeous donkeys in their thick, fluffy, winter coats, past the gorgeous roly poly sheep and pair of alpaca. We retired to the veranda for refreshments after spotting some red browed finch in some camellias. This is when the bird watching really took off! As if on cue a flock of superb fairy wrens zipped into one of the hedges, watched over by a Laughing kookaburra an Eastern yellow robin, Crimson rosellas, and a possible Flame robin!

Over tea the owners spoke of their plans to further extend the rainforest in the future with a view to connect a corridor down into the valley. It would be a massive undertaking, but one well worth the effort in my opinion.

The sun was starting to dip down as we thanked our hosts and headed back to our cars before the temperature dropped too far. Although we didn't see a billion birds, what we did see was well worth it, especially with the walk through the rainforest.

On arriving back in Bundanoon I did a bit of research into the White browed scrub wren. All the images I could find were quite light on the breast, not the rich olive yellow of the ones spotted in Robertson. All but one image I found via Google, which interestingly had been taken in Robertson and put on this blog. So it would seem there may be a colour morph for this species, isolated to Robertson. A nice discovery if it turns out to be correct! 
This revelation got me thinking. If birds can have different colours depending on their location, did Dinosaurs? Maybe one day we will be able to find this out.

No comments:

Post a Comment