I have been doing 'bushfire risk reduction' (dead braches, dry long grasses, dry leaves, fire breaks, etc.) and I have discovered many frogs and toads hiding in odd places (under logs, in hollows, in wood piles, ... no coconut shells ;-) Looking at your little frog in 'Kalaa', I wonder if we understand the situation incorrectly. To me they are hidding from 'harsh' winter conditions and predators who are still hungry whatever the season.

I think, it is wise for frogs to hide under something when it is not time to advertise (to make calls in Nature after good puddle filling rains in Spring).