Have you ever listened outside at night and heard strange sounds coming from the bushland? At this time of year, in the Noongar season of Djeran (Autumn), many creatures are becoming active now the summer heat has dissipated. Here's a short video which might answer a mystery about what that funny sound is near your house...
Burrows in the Bush from Simon Cherriman on Vimeo.
These fantastic Hooting Frogs (Heleioporus barycragus) are the largest member of their group, and the largest frog found in the Perth region, reaching a whopping 9cm in length. Four other species can be heard, sometimes all in the same location as Hooters (see this post for more info). They are endemic to (found only in) the south-west of Western Australia, which makes this species even more special. Despite their size and lumpy skin, they should NOT be confused with an introduced Cane Toad (Bufo marinus)! Toads are larger with a very different shaped head, are more uniformly coloured, and have very obvious paratoid (poison) glands on their back. As you can see in the above photo, this fella has no big glands at all! For comparison you can see a picture of a Cane Toad here.
Confusing a large burrowing frog with a Cane Toad might be an excuse for someone in a car to deliberately run one over, but these creatures often get killed accidentally too. I have found several squashed on roads while driving around the hills on humid nights or after rainfall. The message is to keep your eyes peeled and watch the road carefully while driving. Being armed with the knowledge that humid/stormy conditions or rainfall after long, dry periods will bring frogs out onto our roads can make your more alert to animal activity in your area. It's not nice to think that you have killed a male Hooter who is in the middle of a large walk on his way to find a girlfriend!
Using their strong back legs and the specially designed tubercles on their feet, burrowing frogs dig vertically into the ground with amazing skill. Even in hard clay soils interlocked with a mix of roots and reed stems, Hooters have no trouble digging. Once in position, they excavate a small round chamber and begin calling at regular intervals, continuing their unique 'hoooooot...hooooot...' throughout the night.
|A male Hooting Frog puffs his throat out while calling from inside his burrow.|
If they are lucky and if their calling does the trick, a male Hooting Frog will attract a female into his burrow. He then grasps her in a mating embrace (known as 'amplexus'), and uses large spurs on his forelimbs to grip her firmly. These spurs (see below) are only present during the breeding season, and are a feature possessed by several other Heleioporus species. After mating the female lays her eggs inside the burrow and the tadpoles begin development in a foam nest (as explained in the video above).
Why not put on some warm clothes, grab a beanie and a torch, and take a short bushwalk one evening this Autumn? You might be lucky enough to hear the sounds of burrowing frogs calling near you, and get the opportunity to see one of these frogs up close - an amazing part of our unique natural heritage.