Corvid stalking begins in earnest…#AnimalMOOC Field Notes, Part 2
After several days spent lurking on the couch with a box of aloe vera tissues and a head cold, I thought I’d take advantage of the pleasant weather to do some dedicated corvid stalking. I’ve been keeping an eye on the ravens for some months now, and I suspect they may also have been keeping an eye on me. Time to get serious with this bird-watching caper, and break out the binos.
In many places, birds most easily spotted at either end of the day – dusk and dawn – but here, in the eucalyptus forest with its thick understorey of shrubs and protective weeds, unless it’s raining, there’s usually something feathery worth observing.
After briefly allowing myself to become distracted by a mob of about fifty silvereyes flitting about the blackberries (Zosterops lateralis a.k.a The Grape-Eaters), I lifted my gaze to focus on the corvids at hand.
Where I live, there’s usually a forest raven cawing somewhere nearby. After watching about eight of them swirl through the eucalypt canopy below, I eventually fixed on one bird, about ten metres away and four metres above my eye-line, which was reasonably visible, and appeared more or less settled.
Forest ravens are Australia’s largest ravens (Corvus sp.) – there are three other species, none of which are found in Tasmania, which is handy, as they can be quite difficult to distinguish from one another. They’re also quite hard to pick as male or female within the species – males are slightly larger – so in the interests of gender balance, I’ll be referring to them alternately as female/male.
This was a mature bird, which I could tell from its pale whitish eyes. All Australian ravens go through changes in eye colour as they mature. According to corvid researcher Matthew Brown:
All Australian corvids hatch with blue eyes as chicks, then change to the juvenile brown, then the adolescent hazel before finally becoming the adult white with a blue inner ring at about 2 years old. The process is the same for all 5 species, though the exact time of each stage varies. This is the easiest method to tell the juveniles apart from the adults. Early European scientists used to consider them separate species (the brown-eyed crow and the white-eyed crow) before they finally figured it out.
The callings of forest ravens here is incessant – a harsh “kar-kar-kaaarrr!” The last syllable is quite drawn out, and to me, they always sound a bit like they’re having a whinge about something. In flicking through Pizzey[ possible link] and Knight’s “The Field Guide to the Birds of Australia”,[ reference] I’m amused to note their flight described as “ponderous”. It’s true, they never look to be in much of a hurry to get anywhere, and I see them flying overhead every minute or so. My backyard ducks don’t entirely trust them – they tilt their heads sideways to watch them fly by – and I can’t say I disagree with their vigilance.
Forest ravens have rather catholic tastes in food – they’ll eat all sorts of things. The Birds In Backyards Project notes that while the Forest Raven is omnivorous, it “tends to prefer flesh”. This could take the form of carrion (notably roadkill), small lizards, birds and insects. Ravens are disliked by many poultry keepers for their attentive hunting of unguarded young chicks. They’re also renowned nest robbers, stealing eggs from other birds, and are not above making off with things carelessly left about by humans either. Which is what I think the next raven I saw might have done.
Out of the corner of my eye, I watched her swoop by and land on a nearby branch, apparently unable to close her bill. It looked like she had a largish, round, brown nut stuck in her mouth. She flew from branch to concrete to branch to driveway to eventually land on a backlit branch about ten metres away. During her travels, I was able to fix my binos on her quite well, to see that there was also something red hanging off the brownish round part of the object. What I had thought to be a nut, I now suspected to be a hunk of salami with the skin hanging off it.
On this last perch, she spat out her prize, stood on it, then pulled bits off it, eventually swallowing the lot. I still couldn’t be sure what it was, but whatever it was, she demolished it pretty quickly. She scoffed the last morsel, wiped her beak on the branch, then rammed it into a nearby hole where a twig had once been. After experimentally pulling out a couple of splinters of wood, she flew off and out of sight, no doubt to steal something sweet for dessert.