Australia might not have a huge number of frog species, but the island continent has an amazing variety suited to literally every habitat except the sea. There was one species I had wanted to see for a long time and head searched for with no luck in far eastern Victoria – the mysterious eastern owl frog, also known as the giant burrowing frog (Heleioporus australiacus)
I was given a location near Sydney by fellow frogger Aaron, and it was only a few kilometers from where I was staying anyway so I headed out in the pouring rain for a look. I had not even reached the spot when there, in the middle of the road was a large, fat frog. I slammed the brakes on and stepped out for a look. Indeed it was what I was looking for, a female owl frog. It’s easy to pick the females, they do not have muscly forearms like the males and also lack the array of sharp spines on the arms and hands. After snapping a load of pictures, I jumped back in the car and continued to the car park. The rain was hammering down at this stage, and it didn’t take me to find another owl frog under a shrub, but I was already out of time, having hours to catch a plane interstate.
In a few days I returned to the spot. It wasn’t raining this time but the ground was still very damp. I could hear the grating calls of red crowned toadlets (Pseudophryne australis) deep in the scrub as I walked along in the crisp, cold pre-winter night. A sound next to me caught my attention. I swung the torch beam around just in time to catch a thick tailed or barking gecko (Nephurus milii [formerly the funny sounding Underwoodisaurus milii which sounds more like where to look for one...]). The name barking gecko comes from the gruff bark they are known to make when disturbed, usually arching their back and tail and lunging to bite. This one was an adult with a regenerated tail and unfortunately did not put on a threat display for me.
Only a short way down the track a pair of eyes were looking at me from under a slab of sandstone. A species of Antechinus was watching me intently before turning around and vanishing between the boulders. Superficially like a mouse, these are in no way related to mice, in fact they are marsupials much closer to kangaroos and koalas than true mice. With an insatiable appetite for anything they can catch which includes real mice and spiders – even large scorpions! Unfortunately he was far too quick for me and I never saw him again.
But I wasn’t alone for long, after spooking a bunch of brush tailed rock wallabies, I saw another bit of eye shine glowing back at me. As I moved closer I could see it was exactly what I came for – a large male owl frog. This one was much bigger than the female I saw the previous mission, making it very obvious how they get the name giant burrowing frog. With a brown back and brilliant purple sides finished with a row of yellow spots along the cheeks he was a stunning frog indeed. Looking at the thick arms and the scattered spines on the upper surface of the hands confirmed him as a male beyond doubt. In response to me, he raised himself up on fingers and toes, puffing up. This makes it hard for predators like snakes to get hold of them, and also serves to make them look bigger. He let out some strange owl-like cooing noises and strutted about in this mode as I took a series of photos.
The eastern owl frog is the only known member of its genus in eastern Australia, the rest of the Heleioporus species are restricted to Western Australia and fossils show that these frogs were once found continuously along Australia’s southern coast. They live underground most of the year in burrows dug in soft sand. While they are active, overnight burrows are made so they are safe by day and may emerge at night to feed. During breeding season, males dig burrows next to waterways such as creeks and ponds. There they will sit and make owl-like hooting calls in bursts at a rate of about 4-5 per two seconds. It is a call you will not mistake for any other in their range. Females deposit eggs in these burrows which hatch and the young are released as rising water floods them out.
All in all an awesome frog and one I am glad I put the effort into finding, thanks to a tip-off from Aaron.