Bureau Waardenburg
Varkensmarkt 9
4101 CK Culemborg
the Netherlands
T: +31 (0) 345 512710
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Vogels en vliegveiligheid

Birds, planes and air safety

Effect of birds on air traffic

Collisions between birds and aircrafts cost over one billion euros each year. Furthermore, collisions jeopardize the safety of passengers and may even result in fatal accidents. In the Netherlands, legislations exist that are aimed at protecting the safety of air passengers. These include the Aviation Act (Wet Luchtvaart) as well as wildlife legislation.

At Bureau Waardenburg, we have expertise in the field of birds and aircraft and have undertaken projects in the following areas:

  • research into the number and patterns of risks for air traffic from birds;
  • advice on measures to prevent bird strikes with respect to helicopter flights;
  • determining the effects of spatial interventions in the vicinity of an airport for air traffic;
  • determining the effects of spatial interventions in the vicinity of an airport for nature.

Airport zoning decision and birds

In the Netherlands, one of the instruments for ensuring the safety of air traffic is the airport zoning decision or Luchthaven Indelingsbesluit (LIB). The LIB states that no large waterbodies or bird reserves can be established with 6 km of the airport. This may include plans for open reservoirs, nature management, etc. In such cases permission is needed from the appropriate Dutch ministries before the restriction can be lifted. This requires a wildlife impact study to be carried out, which addresses the following issues:

  • the current landscape;
  • the current bird community;
  • the current flight movments of birds in and around the airport;
  • the future landscape;
  • the future bird community;
  • the expected flight movements of birds in the future;
  • a comparison of the current and future situations, including an assessment of the increase or decrease in risks the safety of air traffic.

Effect of air traffic on birds

Within the theme of air traffic and birds, the effects of air traffic on birds (and other wildlife) are of importance. One consequence of air traffic on birds is disturbance. A considerable amount of knowledge is available on this subject from studies abroad, which have been summarised in various literature reviews. Not all of this research, however, is applicable to Dutch situations. Therefore, research is undertaken in the Netherlands, which covers a number of themes. This research involves both visual observers as well as the deployment of radars.

Aircraft flying at lower altitudes might cause disturbance to birds and other wildlife. It is now known that individual disturbances do not directly lead to the disappearance of an animal from an area. Only when the disturbance occurs in a certain intensity, duration and frequency do birds and other wildlife leave an area permanently.  This can cause numbers within a certain area, such as a Natura 2000 site, to decline and, therefore, conflict with the objectives for the site. For those species and sites that are protected by legislation it is possible to derive criteria, against which the effects of disturbance, such as from air traffic, can be assessed. 

At Bureau Waardenburg, we have experience of estimating the effects of air traffic in light of nature legislation. We have undertaken projects on this subject for Schiphol Amsterdam Airport, Rotterdam Airport, Lelystad Airport, Groningen Eelde Airport, Maastricht Aachen Airport and Midden-Zeeland Airport.

Research methods for birds and air safety 

Birds make use of the lower air layers during their everyday movements. During their spring and autumn migrations they also make use of the upper air layers, particularly when traveling large distances. Visual observations (with binoculars and telescopes) can reveal patterns of local movements, however, the human eye has limitations, particularly in detecting smaller species and over great distances, such as high altitudes. To overcome these limitations it is possible to use radar. A radar can detect flying birds at much greater distances and higher altitudes than observers alone. The disadvantage is that the radar does not identify the species involved and the combination of radar and visual observers is preferable. 

Radar has also proven useful for monitoring bird movements at night; an important time for many species, particularly during migration. In recent years, Bureau Waardenburg has undertaken a large number of projects involving the combination of radars and visual observers. These projects not only include studies in and around airports but also in context of other frameworks, such as the assessment of the potential impacts of wind turbines on birds.

Back to Effect studies on birds