They’re back. If you’re like me and live in one of Victoria’s bigger cities, chances are you might have noticed the influx of Pied Currawongs as the seasons have drifted through autumn and into winter. Maybe you haven’t seen them, but I’m sure you would have heard them even if you didn’t recognise the sound. A wailing ‘Kaaarrr-ooooooooo’ has been piercing the cold of suburban streets as these black and white wraiths slip through the trees on deep, lolling wing-beats, flashes of white in the outer-wing catching the eye with every flap.
Currawongs are intelligent birds – you need only watch them for a few moments to figure this out. Their burnt-yellow eyes are ever-vigilant as they slink from perch to perch. They are usually looking for foraging opportunities, and our cities and towns offer plenty to keep them well-fed. The sturdy bill that juts so prominently from their face enables them to eat a wide variety of foods. Infamous for their prowess of snatching recently hatched birds from the nest, currawongs often bear the scorn of sensitive bird watchers.
But a quick glance at a freshly deposited Pied Currawong poo or regurgitated pellet will immediately tell you that they also include plant foods in the diet. The poos that have been left on my balcony rail recently are deep purple and contain numerous seeds, indicating these particular individuals have been feasting on a glut of berries from nearby shrubs. Currawongs also eat many insects, small reptiles and carrion. And if you have ever left a snack unattended in the backyard, you may have been unfortunate enough to discover that these plucky birds aren’t averse to helping themselves to an easy meal.
So why are there so many Pied Currawongs around our built-up areas at the moment? Despite their varied diet, their primary food sources are all prone to seasonal fluctuations. As spring is the peak period of breeding for many small birds, when the seasons turn and the young birds all fledge, it becomes difficult for Pied Currawongs to find a nest-bound meal. Similarly, insects and reptiles becomes less active as the weather cools down, restricting access to these food sources for Pied Currawongs. Nowhere is the temperature change felt more acutely than in the high country and so, many Pied Currawongs that spent the summer at high elevation come flocking out to lower ground.
Pied Currawongs form large flocks during autumn and winter, unlike during the summer. No longer needing to defend a nesting territory, the territorial aggression breaks down, allowing many birds to socialise. These gregarious flocks make noisy, garrulous calls as they roam across the landscape rendering their presence almost unmissable. Numbers within these flocks may be buoyed by many young birds that left the nest just a few months before. These individuals look almost identical to the adults, but close inspection will reveal a tiny spot of yellow skin at the gape (corner) of the bill, and an overall greyer appearance. The parents care for their young for several months after fledging, but the young must quickly learn the intricacies of foraging if they are to survive through the long, lean winter.
Pied Currawongs aren’t the only currawongs to call Victorian cities and towns home. Keep an eye and ear open for Grey Currawongs. They are very similar in appearance to the Pied Currawong, but are cloaked in ashy-grey rather than black plumage. They also lack the white band on the upper side of the base of the tail (rump) that is present on a Pied Currawong.
Although currawongs are much maligned for predating young birds, the magnitude of effect of this behaviour is likely a symptom of habitat change in our suburbs. Our urban environments are characterised by reduced vegetation cover, leaving nests of smaller birds exposed and easily discoverable to the sharp eyes of a currawong. But rather than denigrating currawongs as barbarians of the bird world, we should learn to appreciate what currawongs represent. Their successful integration into urban areas should be celebrated as a link to the natural world on our doorstep, while simultaneously reminding us that we need to be doing more to provide suitable habitat in our towns and cities for the smaller birds they prey on.
Rowan is a Monash University PhD graduate and now works there as an ecologist. His research interests are broad, spanning seabird foraging ecology to plant invasions. When not in his office, he will most likely be in a woodland with binoculars around his neck and camera in hand.
You can find him on Twitter at @roamingmoth.
Banner image courtesy of Rowan Mott.