Alongside the numerous jets, Zurich Airport is also home to many birds of prey and flocking birds. These include kestrels, buzzards, red kites, and carrion crows, as well as more rarely seen species like grey herons, various types of owls and pigeons, and the common swift. Flughafen Zürich AG (FZAG) actively manages the airport’s green areas—not only for ecological reasons but also to maintain a balance between aviation safety and nature conservation, aiming to reduce bird strikes. SWISS and FZAG work closely together: for example, SWISS pilots report (suspected) bird strikes immediately so that the runway can be inspected and data collected on the type and timing of such incidents. Internally, the crew also reports such events, allowing valuable data to be extracted and trends identified. The ultimate goal is to ensure safe flight operations.

A dedicated ‘Bird Strike’ working group sees representatives from SWISS, Flughafen Zürich, Skyguide, the Federal Office of Civil Aviation and the Swiss Ornithological Institute meet regularly to share expertise and experience. Today, we join Urs Kempf, Head of Landscape & Wildlife Management at Zurich Airport, on a walk through the airport’s green spaces — where we also meet warden Oliver Beck and gain fascinating insights into the delicate balance between nature, people, and technology.

Protecting the birds – both feathered and metal
Part of the Zurich Airport site is a designated nature reserve. "For me, it is the most beautiful nature reserve in Switzerland," Urs enthuses as he watches over the airport’s greenery and its various inhabitants. It’s a place where Urs’s two passions come firmly together – his love of nature and his love of aviation. His ‘safety first’ priority is always crystal clear. "But that doesn’t mean scaring all the birds right off the airport site!" he’s quick to explain. "That wouldn’t even work," Urs continues. "The airport’s greenery and the habitats it offers, along with the local recreation areas just beyond the airport perimeter, are far too appealing to birds for us to be able to banish them for good. So what my team and I try to design the habitat in such a way that as few birds as possible choose to settle here permanently."

Natural habitat management: fewer mice for fewer birds of prey
One example of Urs and his team’s approach: the grass beside the airport’s runways is only mown one side at a time. Birds of prey will find their quarry more easily in freshly cut grass. So mowing only one side at a time discourages these birds from flying across the runway in search of their food. The ‘mouse fence’ is a further means for Urs and his team to keep nature at bay. The four kilometers of 40cm-high fencing (complete with mousetraps) that run along the runways’ mown-grass edge strips keep mice – and thus birds – away from the runways. The traps are special, too. Mice can enter them and use them for shelter, but cannot get out. The traps can, however, be opened by foxes, which can also scent from afar whether a mouse is inside. Weasels, too, are excellent mouse hunters and thus useful airport residents. In view of this, Zurich Airport has even conducted a special project to construct several branch-and-twig piles, which make ideal weasel homes.

In one case, wood pigeons were frequently observed in a specific area of the airport. They were particularly drawn to a gravel parking lot, as this pigeon species swallows small stones to help grind up their hard food. Eventually, the round gravel was replaced with crushed aggregates. As a result, the pigeons no longer search for grit near the runways and no longer pose a threat to aircraft.

Bird control: keeping everyone safely apart
Despite all preventive measures, sometimes the birds simply have to be scared away. When this is necessary, the primary objective is to avoid merely displacing the bird strike threat to a different runway. With this in mind, such activities—such as firing bird banger guns—are carried out only by trained wardens and the Airport Authority, who are thoroughly familiar with the various types of birds, their behavior, and their likely escape routes. Warden Oliver demonstrates how he uses warning bird banger ‘shots’ to frighten off large birds for which, for safety reasons, a zero-tolerance policy is pursued. All too often, though, he can’t adopt this particular practice: birds like the carrion crow are so smart that they will soon learn to ignore banger shots or laser deterrents. They’ll even recognize vehicles and their occupants, such as the wardens on patrol.

All the various actions taken at and around Zurich Airport place a firm emphasis on maintaining the natural balance among the region’s fauna. One thing is clear: the wardens and the ‘Bird Strike’ working group never run out of work. It’s a never-ending story, though. No fence will keep birds out of the airport area. And making such a naturally attractive habitat as unattractive as possible is a massive task. But it’s a vital one, too – to optimize flight safety for all the ‘birds’ involved, from both the natural and the technological world.

 

Interested in more information? Then listen to the FZAG Podcast (in German)
“Dominique Conrad, what animals live on the airport grounds?”
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