#AnimalMOOC Field Notes, Part 4: The chilly edition – in which the birds hide from me, and I am too cold and sooky to chase them down.
Yesterday morning when I woke up, the mountain was dusted with snow.
Mount Wellington, or kunanyi in a local indigenous language, looms over large over the town and peoples of Hobart, physically and sometimes metaphorically. In Hobart, the Mountain is the centre of all things – defining topographical feature, super-sized weather vane, and reminder that our small city is tied directly to the Tasmanian Wilderness World Heritage Area, by geology and by vegetation. And when there is snow on the Mountain, Hobart is cold.
Forest ravens and currawongs abound in Tasmania’s mountain regions. The currawongs in particular are drawn to areas inhabited by unwary backpackers, and will wait, patiently, beady-eyed, for the moment when a sandwich is left unwatched, a pack left unattended. I’ve had a bushwalking friend tell of a currawong encounter at a track junction on the well-travelled Overland Track. Other bushwalkers had foolishly left their hiking packs, zips exposed, trailside, as they bagged a nearby peak. My friend had arrived to a currawong-facilitated shambles of torn food packaging, strewn socks and ravaged apples, just before the pack owners returned, who promptly accused him of this wanton vandalism. He protested his innocence, pointing out that if he’d been rifling through their packs, he would have taken more than their muesli bars. He told them about the currawongs, but they refused to believe him.
If they’d done even a little research, they’d have discovered that currawongs in high-traffic bushwalking areas are renowned for their cunning ways with pack zips – they grab onto the zip tabs with their strong beaks and yank open bags, to get at the tasty trail mix within. They are very naughty birds!
In my street, they show similar guile in dealing with netted fruit trees.
In yesterday’s chill, there seemed to be fewer ravens around in the forest across the road – although I could hear them about, I struggled to set eyes on them. Then I remembered my neighbours’ persimmon tree. I wandered next door to find that the birds had completely stripped the netted tree – they’d simply unpicked a bit of the netting and pushed their way in, scoffing all of the fruit, to my neighbours’ mild annoyance. But none were to be found in their yard today, probably because they’d eaten everything that was of any interest.
I suspect the colder weather has changed their distribution, which would be interesting to look into.
Black currawongs are known to be altitudinally nomadic, moving down hill in winter, and returning to the mountains as spring returns. They turned up here a few months back in numbers I hadn’t seen, possibly moving to take advantage of better food sources in the lower, warmer, urban areas.
Like many non-traditionally-aesthetically-pleasing, common animals, the Forest Raven is relatively little studied, and many basic details of its behaviour and ecology are not necessarily known. It’s thought that mated pairs hold permanent territories of around 40 hectares, but this is likely to vary with availability of food resources. Non-breeding birds hang out in flocks of about 30-40 birds, with groups swelling to mobs of up to 100 over Tasmanian winter.
Later in the afternoon, I walked up the mountain a little, looking for them in the roadside forest tracts, but once again, could hear, but not see them. I suspect that the birds who are normally in the forest across the road from my house have probably moved en masse to the tip, and are propped up on the nice warm compost piles picking at the dinosaur bones. But it’s far too chilly for me to go and test this hypothesis 😉
All of the details of bird ecology in this post are taken from Pizzey and Knight, 2010. The Field Guide to the Birds of Australia (8th edition). HarperCollinsPublishers Australia Pty Limited.