At this time of year the days are becoming colder and most animals are becoming less active, or migrated north. This stillness and quietness of winter becomes evident. However there are a few specific vegetation communities which can occasionally provide an abundance of life in the onset of winter, and it’s all controlled by food. One of these vegetation communities are the Casuarina swamp lands which line undisturbed river lines in eastern Australia. Most inland rivers are cloaked by the River She-oak (Casuarina cunninghamiana), usually 20 meters each side of the bank, but sometimes more or sometimes less depending on the geological architecture of the area.
These Casuarina swamp lands can become a very important niche for many different species of birds during the onset of winter. The reason for this does not lie with the Casuarinas specifically, but surprisingly a parasitic plant which lives on the Casuarinas. These plants are known as mistletoes. While mistletoes have adapted to mimic a multitude of different host tree species, the mimicracy displayed by the Needle-leaf Mistletoe (Amyema cambagei) is extraordinary. This mistletoe has evolved to mimic Casuarinas and Allocasuarinas, and does a remarkable job of disguising itself amoung the Casuarina needles. Unless you are a mistletoe expert, the only sure-fire way to discern mistletoe from Casurina is to witness the Needle-leaf Mistletoe in flower (which are incredibly beautiful and unique!). Casuarina flowers are much different from mistletoe flowers and look like small fluffly red or brown parts on the leaves (needles), while the Needle-leaf Mistletoe flowers have large bright red anthers that a readily distinguishable, and are probably that bright to attract the birds!
The Needle-leaf mistletoe usually flowers at the beginning of spring, however I must of been at the right place at the right time as thousands of Needle-leaf Mistletoe were in flower, giving the Casaurinas bright red highlights which contrast well among their dull foliage. This earlier flowering could probably be due to the large quantities of rain south eastern Australia has had in the preceding months. With waning nectar resources from other tree and plant species, it seemed all the nectar feeding birds in the area decided to take advantage. We were treated to an avain frenzy of tweets and feathers. There were many bird species I didn’t manage to get a photo of and many bird calls I couldn’t identify, but below are some notable entries.
The last bird shown above is the Turquoise Parrot which is threatened in NSW. This was an especially great find! They even landed for me to take a photo, however they chose the ugliest invasive weed species to land on, I was in any case excited.
While the bird life was astonishing, there were other appearances which you usually only get to see in areas which are healthy and remote from urban development. The area harboring this biodiversity is situated between Nattai NP and Yerranderie Conservation Area along Wollondilly River, which gives wildlife to solitude it needs to become especially diverse and abundant. The healthy sections of this river is known to be home to the Platypus (Ornithorhynchus anatinus), which I was especially lucky and excited to witness. The photo isn’t great but I was able to view it with binoculars as it would emerge and submerged for ten meters. On the banks of the river I was also able to see a healthy Common Wombat (Vombatus ursinus) grazing, and well as huge amounts of butterflies fluttering around, which turned out to be the Monarch Butterfly (Danaus plexippus) and Lesser Wanderers (Danuas chrysippus). I am unsure if these butterflies were here for the mistletoe nectar or for some kind of migration.
To witness this spectacle of nature was an inspiring reminder that there are still untouched oases of life which escape the reach of man with the addition of wonder with how many features of animal ecology remains unknown.