Most people would walk past this old blackbutt without giving it a second thought. David Waterhouse couldn't.
Over years of watching wildlife in the bushland near Sydney's Georges River, David has seen its hollows occupied by cockatoos, possums, parrots, bats and boobook and powerful owls, each taking their turn in one of the busiest addresses in the neighbourhood.
A lifelong observer of nature and a WWF-Australia supporter who has chosen to leave a gift in his Will, David shares the story of a tree that taught him just how many lives can depend on a single patch of habitat.
Have you ever stood near a large city apartment block and wondered about the lives of those who live there? Some of those towering blocks are prime real estate and much sought after as places to live.
Surprisingly, the natural world has a close equivalent in the form of large trees which, when old and decaying, provide desirable residences for a whole host of wild things.
One such tree is an ancient blackbutt (Eucalyptus pilularis), growing on the side of a steep slope in a bushland council reserve, a few minutes' walk from where I live near the Georges River, Sydney. It may have been standing in the early days of European settlement, or even when the Bidjigal clan of the Eora people hunted and fished around those slopes before suburban development came.
The ancient blackbutt in close proximity to a rusty gum (Angophora costata) in suburban Oatley, NSW. © Courtesy of David Waterhouse
Mature blackbutts have a covering of rough bark at their bases and main trunks, but very smooth, creamy bark on their upper trunk and branches, where the bark covering peels off and hangs in ribbons.
This particular blackbutt has grown double-trunked and stands 18 to 20 metres tall. From about halfway up to the highest dead branches it contains many hollows, not all of which are apparent from the ground. The base of this huge tree is on the slope below the access path which allows a better view of its upper section, but you must still tilt your head to view the treetop with its upper hollows.
A grand blackbutt photographed by David at Limekiln Creek, NSW. © Courtesy of David Waterhouse
In summer, when the tree flowers, the pale-coloured blossoms provide nectar and pollen for fruit bats, a variety of insects, as well as noisy miners, rainbow lorikeets and sometimes musk lorikeets. But its real appeal for the resident fauna is its hollows, some eaten out by termites, others formed by snapped-off dead branches.
In springtime, such high hollow stubs are hotly contested by a variety of parrot species, including the ubiquitous rainbow lorikeets, crimson rosellas and sometimes king parrots. The hollows will also be occupied by sulphur-crested cockatoos. Eastern rosellas have attempted to claim hollows but are chased off or, on one occasion that I observed at least, forcibly dragged out by rainbow lorikeets.
Occasionally, a pair of galahs may be seen to claim a hollow and duly line it with sprigs of eucalyptus leaves, as is their habit.
Also, in the warmer months, a boobook owl may roost during the day in a medium-sized hollow, emerging at night to hunt. Long before dusk you can always tell if a hollow is occupied by an owl because flocks of fussy noisy miners create a racket outside, some daring to peep into the retreat.
Cockatoos may also add to the noise at dusk, landing near the hollow spout, raising their crests and shrieking loudly. One evening I saw the owl promptly emerge and rush at a cockatoo to quiet it. All that did was excite the cockatoo and its companions, who shrieked all the more.
The main hollow is taken over in most winters by a pair of powerful owls unless the cockies are still nesting. Once, on dusk, I observed a powerful owl approach the lip of the hollow which still contained a cockatoo family. The predator looked in the hole, made a ‘mooing’ sound for a while and then departed.
Now, this owl is quite capable of seizing and killing a bird the size of a cockatoo, but this occurs when snatched from a tree branch and not, apparently, when they are in their hollow fastness at night.
Mammals which use the higher hollows for sleeping in during daylight hours (if they can ignore the parrots screeching) include microbats, ringtail possums and sometimes brush-tailed possums. They emerge on dusk to search for food. Unless you are watching the tree at dusk you would never know they were present.
Now, the main prey of the powerful owl is the ring-tailed possum. I have seen many a one brought in to feed the owlets on a cold winter's night. Those large owls catch and carry around two hundred of the marsupials a year, supplemented with brush-tailed possums, birds and fruit bats, as well as large insects when the young are small.
Yet, over the years, I have seen both ring-tailed and brush-tailed possums appear from their hollows close to the owls only to be ignored.
While I originally spent time near the ancient blackbutt to observe powerful owl behaviour, I soon came to appreciate that this high wooden apartment block was inhabited and relied upon by a whole suite of other creatures off and on.
There is more to be learned and discovered yet and this must be true of any grand old tree full of hollows.
David still returns to the old blackbutt whenever he can. Even after years of watching, the tree continues to surprise him.
That's the thing about nature. The closer you look, the more you discover. What appears to be a single ageing tree can turn out to be a nursery, a refuge, a hunting perch and a home for dozens of different species over the course of a year.
It's also why David has chosen to leave a gift in his Will. The old blackbutt has shown him how many species can depend on a single tree, and how important it is to protect the habitats that wildlife needs to survive and thrive.
By leaving a gift in your Will to WWF-Australia, you can help protect wildlife and the places they call home, creating a lasting legacy for nature for generations to come.