The Wilder Side of Vienna

Notes from Nature: Jun. 2010

R S Hughes
Jun 01, 2010

I’m walking in the manicured grounds of Schönbrunn with Thomas Bugnyar, Professor of Cognitive Ethology at the University of Vienna. It’s late afternoon; heavy thunderclouds have dispersed and a monsoon-like downpour has just rained itself out. Moments ago, shrieking schoolchildren ran for cover and mothers desperately shielded babies and toddlers with umbrellas too small for the job. Now though, the wet lawns and paths are beginning to steam under a hot May sun, and a pale woman uses an umbrella to shield herself from its rays.

On the gravel path just two or three paces ahead of us, a carrion crow is sunbathing; its black plumage suffused by oil-like rich blue, green and purple hues. Standing quite still, it is unperturbed by our presence and opens its beak before cocking its head jauntily to one side. "This is one of the reasons I like corvids so much," says Thomas, using the term that encompasses all members of the crow family. "City birds allow you to study them very closely and they display fantastic characteristics." He particularly enjoys seeing the birds at play, chasing one another or dropping objects from great heights and deftly catching them before they hit the ground.

Despite meeting at Schönbrunn’s historic Tiergarten, home to giant pandas, polar bears and all manner of other exotic animals, we have come to discuss nothing more uncommon than the aforementioned crow. Working with students Rachael Miller and Martina Schiestl, Thomas has been conducting a study of the carrion and hooded varieties that appear to have made the zoo their own. "Around 300 birds are currently using the zoo as a kind of supermarket," he says. The birds are stealing food from the enclosures and teasing the animals – hopping up to them, pecking and twisting their fur and flying off to much merriment. "They especially seem to like the kangaroos," he adds.

Thomas specializes in the cognitive aspects of animal behaviour, something that means he’s particularly attracted to corvids. Among the largest-brained of birds relative to their size, they’re quick learners and highly innovative. "We always have to be careful not to attribute human behaviours to birds and animals, but if a child passed some of the tests we set for the birds, we’d consider that child to be a good thinker."

Vienna is home to several species of corvids: carrion and hooded crows, jackdoors, rooks, magpies, jays and ravens. Each species roosts together to protect against predators (primarily the eagle owl in middle-Europe), and there are many roost sites across the city. Around 200,000 birds or more may gather at the largest during the winter months.

As well as petty theft and ungentlemanly behaviour, the crows of Schönbrunn are causing more serious problems, such as disturbing animals during breeding seasons and stealing eggs – one of the reasons the zoo itself is funding the study. By examining the behaviour of the birds, Thomas aims to put a stop to the problems. Among other things, he hopes to teach the offending individuals that eggs found in animal enclosures are not worth stealing.

"Maybe we’ll plant dummy eggs that taste really ugly," he says. "This learning won’t last forever of course. But it should get us through the critical periods."