At the end of September I noticed these incredible scratchings on a Silver wattle on my property in Porcupine Ridge. They occurred all the way up the small tree, to about five metres high. Just a few exploratory marks had been made on the other side of the trunk.

I checked beneath the wattle for bird droppings or sugar glider scat and the only evidence on the ground was the shavings of wood that had come off the tree.

According to “Tracks, Scats and other Traces” by Barbara Triggs, Sugar gliders “gouge out the bark with their lower incisors, leaving vertical or horizontal gashes from which they lick the sap that exudes”. The depth of these gouges and the beautiful curlicues that have formed look like they had incredible strength in their lower jaw!

The mark in the top right does look very much like it may have been made by a lower jaw and pair of sharp teeth scraping upwards.

There was a small insect or two on the exposed wood, but nothing that looked like a sap site. But I admit I have not had the chance to see a glider sap site up close!

Another possibility is parrot damage – but usually a Yellow-tailed Black Cockatoo makes exploratory marks for a beetle grub or borer, and then when the beetle is located, the bird really hacks into the bark and wood to locate and extract the grub. There was no evidence of this occurring.

I will return to this mystery once I have sought some advice from other naturalists!