Few Australian mammals are active in the daytime, preferring to do their scuttling around the landscape under the cover of night. An exception is one of the most unusual mammals in the world, the Echidna. Protected by a prickly array of spines and with a taste for ants and termites, the rolling gait of the echidna is a regular sight in Sydney bushland.
This one was immature, roughly two thirds the size of a fully grown adult. We spotted it crossing the fire trail up ahead. By the time we reached the Echidna it was poking its nose into an ant nest in the sandy edge of the track. It didn’t react to our approach until I was about 5 metres away, when it suddenly stopped walking, hunched its back, tucked the head under the chin and dug all four claws into the soft ground. In that stance all we could see was a mass of sharp spines pointing out of the ground.
From past observations I knew that if we stayed quiet the echidna would soon forget our presence and resume foraging. I sat down only half a metre away, and sure enough within a minute the neck relaxed and the long tubular nose emerged from the forest of spines. The click of the camera shutter caused the nose to dart back out of view.
I leant in and was surprised to see dozens of ants climbing over the Echidna’s back. The harsh smell of formic acid confirmed the crankiness of the ants. I took a close up then stepped back a few metres. A moment later the Echidna flexed its back and strolled off into the heath.
Later, reviewing the images, I noticed that few of the ants were on the Echidna’s wiry fur. Instead they all seemed to have climbed onto a spine, and mostly out to the tip. The ants’ mandibles bit futilely at the impervious tubes and their abdomens sprayed acid in the hope of driving away the Echidna. It left me wondering whether the spines play a dual role, protecting the echidna from large predators but perhaps also rendering the defences of the ants, their own prey, largely ineffective. A short wildlife encounter but a thought provoking one.
Odds and sods