In an airport or an airbase, a runway is an essential component. When you think of airport runways, the first thing that comes to mind is aeroplanes. In a general sense, an aeroplane uses a runway for take-off and landing. It should be a noisy, undesirable place for birds but unfortunately is quite the opposite and birds have been known to use it as a resting and loafing site.
Image: Screenshot from video 'BOEING 747 vs. 200 BIRDS waiting at END of the RUNWAY (4K)'
Factors that attract birds
1. Warmth
One of the main factors the runway is such an attraction for birds is the warmth it provides. The runway’s asphalt absorbs and retains heat longer than its surroundings, attracting wildlife to use it to stay warm on cooler days. The incidences of birds sitting on a runway have occurred in the coldest climate and even in the tropics. South polar skuas, a type of seabird and developed a habit of sitting on the Antarctic snow-free airstrips for warmth. Bald Eagles have been recorded to sit on the runway in the morning to probably warm themselves before leaving to forage. Similarly, in the tropical climate of Singapore, White-bellied Sea Eagles and Ospreys were observed sitting on the runways at Changi Airport and Seletar Airport respectively in the mornings.
2. Post Rainfall provides a buffet of invertebrates
On the flip side, after rainfall, runways attract invertebrates that are avoiding the wet soil by coming onto concrete areas and thus increasing their availability to their predators such as gulls for example. The gulls come will come to eat and thereafter loaf, sit on the wet runways undeterred by the dampness. Additionally, when the stormy weather prevents gulls from roosting at their usual sites at sea, on islands or coastal bays, they find safety and security near or on runways of coastal airports.
3. Shelter and Safety
Shelter, safety is another motivation for birds coming to the airport runways as ironic as it sounds. The wide space and short vegetation give birds security as they are able to roost in open spaces with good all-around visibility. The open area a runway provides also attracts birds that tend to congregate together, flocks of migratory birds are known to use airport surfaces as resting sites during migration. Swallows are an example of bird species that tend to flock and forage together, the migratory species of swallows have been observed resting on runways in flocks.
What can be done to prevent them coming onto runways?
To sum it up, runways are seen as a place of shelter, safety, warmth or easy food pickings depending on the bird species and the surrounding environment. Unfortunately, while birds may find runways as a safe resting site, it clearly is not with risk of collision with an aeroplane using the runway. Various dispersal tools are usually used to chase the birds that sit and rest on the runways. In the long term, a combination of both active management and passive management strategies such as habitat modifications is needed. Understanding the birds’ movement trends and regular foraging behaviour is important. There is no clear-cut standardised solution for any airport but with constant research and trial-and-error there is always room to improve the mitigation strategies.
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