Day 4- 22/10/10 Frogs and fire

This morning saw us head for the fire scar, a vast swathe of burnt-out mallee in the southwest sector of the sanctuary. The fire occurred in 2006, and it was interesting to see how the vegetation had regenerated in the years thereafter. The mallee bushes had obviously perished in the fire, but the plants themselves survived and were growing profusely from their bases. The bush was now studded with young desert poplar (Codonocarpus pyramidalis), and the undergrowth was lush with various wildflowers, all in bloom due to the recent rains. The range of colours gladdened the eye, and we marvelled at the presence of plants that had lain dormant for the last 20 years, awaiting just such a wet period. I lament to this day my lack of proficiency as a botanist, though I could appreciate the diversity in what, to most people’s minds, would be a sterile, unremarkable region. The mallee was a long way from regenerating to its true self, but the plants were obviously taking full advantage of the spike in resources, and it would surely be a matter of time before the mallee reclaimed the land for itself, phasing out the poplars, eremophilas and wildflowers. Ecological succession in action.


One reason I enjoyed the fire scar was the sheer openness to the habitat: nothing grew much above head height meaning obscuring foliage was nonexistent, and the dead mallee branches left ample perching spots for birds. Rainbow Bee-eaters (Merops ornatus) were ever-present, while woodswallows were exceedingly common, and we soon saw every species on the sanctuary: Dusky (Artamus cyanopterus), Masked (A. personatus) (above), Black-faced (A. cinereus) and White-browed (A. superciliosus) (left). The latter two were new for me, and were the ones I needed to complete my own clean-sweep of the group. We also got our first Red-backed Kingfisher (Todiramphus pyrrhopygius) and our first good looks at Crimson Chats in full breeding plumage as well as Crested Bellbird (Oreoica gutturalis), a new one for me, commonly heard but only rarely seen. Our penultimate site, a scrub patch away from the fire scar, yielded a true gem: Southern Scrub-robin (Drymodes brunneopygia) (top of article), two in fact, all too ready to pose for photos. I also heard my first Horsfield’s Bronze-cuckoo (Chrysococcyx basalis), which we endeavoured to find, but alas our efforts were futile. We finished up our morning at a belah (Casuarina pauper) woodland, which produced White-browed Treecreeper (Climacteris affinis) (below), also a new one for us, and a new herp for me, my first Tree Skink (Egernia striolata).


That afternoon was Round 2 of Black-eared Miner surveys. Once again, we did transects over the dunes, stopping to play that reviled recording every 500m. The previous day, it took us nearly half the afternoon to find the birds; this time the reward was instant: a quick burst on the megaphone at our first stop, and seven miners swooped in. This time they were more cooperative, staying close in for almost ten minutes, which allowed us to not only get photos but decent visuals as well. We managed to observe social behaviour: half the flock was a family, with full-grown fledglings following and begging from a parent. The photos later revealed two BEMs; interestingly one of them was a begging youngster, soliciting food from a hybrid parent along with its hybrid siblings (left). Our first two full days here, and we had two BEM sightings. Endangered? Hardly.

We watched as ominous clouds swept in from the southwest: rain was coming, and it was expected to hit either later that night or the next morning. As before we finished the transect on the look-out, not just for miners, but for anything else that might cross our paths. Towards the end, we were rewarded, albeit in a rather confusing fashion. We first heard a Black-eared Cuckoo (Chrysococcyx osculans) calling cryptically from a low bush. Our attempts to flush it caused a bird to take flight and land in a high tree. Going after that, we noted distinctive pied plumage; I recalled the book’s description of a Black Honeyeater call [quite similar to the cuckoo’s, a high pitched ‘seee’] and speculated it might be that, just as it turned around and revealed its true identity: a male White-winged Triller (Lalage sueurii). All the while, our attentions were divided between that and a commotion behind us, which turned out to be the desired cuckoo (below) being mobbed by a family of Chestnut-crowned Babblers. A hashy ending to the day, but still a decent tick. The lesson:

A cuckoo.

Not a cuckoo.

After dinner, we took advantage of the warm night to walk to a nearby dam for a spot of herping. The walk brought instant yield -our first Beaded Geckos (Lucasium damaeum) (below), and a very large yellow scorpion- but the dam itself was a little disappointing, just a few crayfish (Cherax sp.), although one had a very large and engorged leech (Hirudinea) attached to it. At a nearby soak, we noted some very large tadpoles; Scotia has, unusually, only one species of amphibian, a burrowing toad (Neobatrachus sp.), the exact identity of which is a little confusing. It was first thought that two species were present, N. centralis and N. pictus, but the present consensus is that there is only one, listed as N. sudelli. There is, as yet, no definite explanation as to why Scotia only has the one species; desert-dwelling amphibians are reasonably diverse elsewhere including species such as burrowing frogs (Cyclorana sp.), desert treefrogs (Litoria rubella) and other burrowing toads e.g Notaden sp. The answer seems to lie both in the ephemeral nature of the water supply [Scotia has no running water], and in the burrowing toad’s life cycle, in which the tadpoles exhibit cannibalism.

Burrowing toads produce two kinds of offspring, one a slow-growing algal feeder, the other a fast-growing meat-eater. In good rain periods, both will be able to mature without issue, but in drier periods, when resources are limited and the pools far more ephemeral, the fast-growers have the edge, and through cannibalising smaller tadpoles, ensure that at least they mature. Given this penchant for cannibalism, it is possible that the burrowing toads have successfully excluded other amphibians from the region, literally eating other species out of house and home.

All this while, the clouds continued to build, and as the winds picked up and the first spatters of rain began to fall, we were forced to turn back. It didn’t bode well for the next day.