The ocean was as calm as I’ve ever seen, with lines of current flowing like rivers across the surface. There was a series of smooth oval patches on the water’s surface, the closest only 50 metres away. Within a few seconds of my arrival two humpbacks rose to the surface, creating the next in the line of ovals. The tall plumes of the whale’s breath glowed golden in the early morning light, a gorgeous contrast against the dark blue of the sea. I’d wondered whether the Humpback migration had finished, clearly not.
As chance would have it they were the only whales I saw that morning. To one side of my vantage point was a massive field of boulders. They had detached from the cliffs above and tumbled into a heap that started at the water’s edge and continued half way up the slope. An insistent piping call was coming from below, a pair of Rock Warblers. I watched them bouncing from boulder to boulder as they searched for insects and other invertebrates. One of the Rock Warblers flew away and returned with a strand of vegetation in its beak. The two chattered loudly before disappearing into a deep crevice.
The crevice was formed by the separation of a couple of massive boulders from the cliff edge. It was capped by another large boulder, creating a cavity roughly 5 metres deep, 2 high and half a metre wide. A bit of careful scrambling and I was able to drop into the cavity. The walls were damp and covered in algae. On the junction between roof and wall a thin line of roots could be seen poking out into the air. Once my eyes adjusted to the dim light I could see a ball of grass, twigs, seaweed and spider web hanging off the exposed roots. The entrance to the nest was positioned near the top with a carefully constructed cover to deflect water.
Neither of the Rock Warblers were in evidence although I could hear one calling nearby. The main opening of the crevice faced out to sea however a couple of much smaller, warbler sized gaps allowed access from the other end. The nest was protected from the worst of the weather and virtually predator proof. The downside of the underground location is that it was cold, dark and very damp. I could see spider web woven amongst the vegetable fibres and suspected that there is more inside to insulate and line the nest.
I took a quick photo, crawled out of the crevice and climbed back up the slope. Nearing the top one of the Rock Warblers zipped passed then stopped to scold me from a couple of metres away.
A couple of days later I watched another pair of Rock Warblers foraging along a coastal creek. Erosion of the horizontally bedded sandstone created wide overhangs and deep crevices along the banks of the creek. One of the Rock Warblers was working its way along a crevice, often disappearing from view to re-emerge a dozen metres away. It struck me that Rock Warblers act more like a rodents than birds, happily squeezing into the smallest, dampest crevice or gap in the sandstone. They only occur on the sandstone of the Sydney basin, suggesting that there is something special about the way that sandstone fractures and erodes that allows these speleologists of the bird world to flourish.
Rock Warblers are one of Sydney’s unique wildlife wonders. Sulphur Crested Cockatoos are not on many local’s list of wonders. It is, however, worth pushing past their abundance, unbelievable loud calls and ability to deconstruct anything that captures their interest. They are amazingly intelligent animals with an energetic and combative social life, a naturally photogenic species that offers many interesting opportunities.
An image I haven’t managed to capture as yet but which sums up the species is when sedately passing Sulphur Crested suddenly twists through a couple of barrel turns, side slips and drops into a vertical dive before pulling up just before it crunches into the ground. Truly crazy wildlife.