Early morning and the crows are raucous, flocking to the Moreton Bay fig tree after the fruit, noisily telling their friends and family about it. I say crows because that’s what I call them, but officially they are ravens – Australian Ravens.
Whatever they’re called, they feel no need to hide away. They’re loud. They crash through the tree’s branches, dropping as many figs as they eat. The dropped figs hit the ground around me. I’m being bombarded. One bounces off my hat. They plonk loudly into the lake’s water. The ducks swim over and eat them, grabbing them as they sink. The ravens converse loudly over their breakfast.
They are opportunistic feeders, which is a polite way of saying they eat just about anything. Birds of Southwestern Australia (Denis Saunders and John Ingram, 1995) tells me Australian ravens feed on ‘fruit, seed, grain, flowers, berries, snails, millipedes, centipedes, cockroaches, termites, mantids, ear-wigs, grasshoppers, crickets, stick insects, lice, bugs, cicadas, beetles, moths, caterpillars, cutworms, ants, slaters, spiders, ticks, fish, frogs, lizards, birds and their eggs, mammals and carrion.’ Like I said, just about anything.
They hang around my chook pen, looking for a way in to get the eggs. They cock their heads and eye the eggs in the nest box, tantalising but unreachable. I used to have a loose flap hanging down near the nest boxes that I lifted to collect the eggs. Eggs started disappearing and I realised the ravens had worked out how to lift the flap. It has now been secured and the eggs have stopped disappearing.
My old dog used to chase the crows down in the off-lead dog exercise area. She had learnt that crows often have bones or other tasty morsels that they would drop if startled. The dog would then steal the bone. My new dog, still a puppy, is not so smart. She chases the crows for the fun of seeing them fly but hasn’t yet realised about stealing bones from them. Nor has she realised that they are stealing bones from her. The crows sit on the back fence and jump down when the dog is distracted and nick the bones before flying off.
There, I slipped back to calling them crows even though I had just said I know they are really ravens. There are crows in Australia, just to confuse matters. Ornithologists call crows and ravens Corvids and they are all in the same genus – Corvus – so are all closely related. Some sources say there are six species of Corvids in Australia, some say five. The discrepancy is in whether they include the House Crow (Corvus splendens). It is an introduced species, native to various parts of Asia. The other five species, all indigenous to Australia, are the Torresian Crow (C. orru), Little Crow (C. bennetti), Forest Raven (C. tasmanicus), Little Raven (C. mellori) and the Australian Raven (C. coronoides). I can’t find any explanation as to why three of the Corvids are called crows and three are called ravens, which makes me think it’s a little arbitrary. Common names are often confusing. That’s why biologists use scientific names (which are the ones in italics). Scientific names follow a rigorous protocol and tell the story of genetic links between living things. The scientific names avoid the ambiguity of common names that so often vary from region to region, and are often misapplied anyway.
The Australian raven is the species commonly found in Perth. The birds stealing bones from my dog, eyeing the eggs in my chook pen and dropping figs down by the lake are Australian ravens. All of the Corvids are glossy black birds with sharp beaks. The Australian Raven is distinguished from all the other species by having long hackles under its beak. My well-thumbed copy of The Slater Field Guide to Australian Birds tells me these hackles form a ‘prominent fan while calling or displaying.’ This little fact confirms the birds sitting on my back fence are ravens, in case I was in any doubt. I really should stop calling them crows. But I am not about to start saying ‘the Corvus coronoides are hanging around the chook pen again.’
All of the Corvids evolved in Australia and science confirms what many of us already suspected – they’re smart. They have the biggest brains compared to body size of any birds and they put their intelligence to good use. They are one of the few species that has greatly benefited from urbanisation. They loot rubbish bins for discarded bits of hanburger and chips. Then there are the dog bones and chook eggs and road kill. They do more than just fossick among the rubbish though. Corvids have been known to use discarded bread as fish bait. They took the bread, dropped it in the water and watched until fish came up to eat the bread. They caught and ate the fish. They traded up the bread for fish. Impressive. Up-cycling, Corvid-style. As the scientists who studied this behaviour reported, this shows planning and intent, both of which are high brain functions. Corvids also drop shellfish and nuts from height to crack shells. They use tools to get food out of cracks and crevices. They have complex social hierarchies and pairs mate for life. They have strong pattern recognition. Ornithologist Dr Stephen Debus writes that ‘Corvids recognise people carrying guns, they avoid traps, and they follow and harass large predators for food, or follow trappers and steal bait from traps.’ He also says they can count to about six. I’m not sure why I am surprised by this, but find I am. Counting seems such an intellectual thing to do.
I’ve heard of people hanging a dead crow (or raven) on the fence of their chook pen as a deterrent to other crows (and ravens). Given their intelligence perhaps it works. I hasten to add that I’m not about to try it. I’ll stick with making sure my chook pen is crow/raven/corvid proof.
Thanks for reading.
Jill