Bird strike
Birds are part of our familiar cityscape and enrich our everyday lives with their songs and daring flight manoeuvres. However, they are exposed to various dangers, especially in urban areas. One of the greatest threats to our native bird species in cities comes from transparent and reflective glass surfaces. The State Working Group of Bird Protection Centres estimates that more than 100 million birds die every year in Germany alone as a result of a collision with glass.
The problem
Transparent views, such as glass connectors, bus stop shelters or corner glazing, suggest that birds have a clear flight path to areas behind them. If glass surfaces provide a lifelike reflection of the surrounding vegetation or the open sky, this can lead to panes being mistakenly approached as potential habitats.
The bird strike often remains undetected. Only in the case of larger bird species is it sometimes possible to trace the impact afterwards, for example through an imprint of the plumage or feathers sticking to the window pane. However, the fact that the carcasses of dead birds are often removed after a short time by various scavengers also contributes to the presumably high number of unreported cases.
The well-known and still widespread bird of prey silhouettes, which are occasionally affixed to windows, are ineffective as protection against bird strikes and should therefore not be used. The birds do not recognise a threat from a predator in the rigid silhouette. Although they perceive the sticker as an obstacle, the surrounding glass pane remains invisible to the birds.
Effective bird protection patterns can be applied over a large area to effectively prevent bird strikes. A list of these patterns can be found in the current brochure from the Swiss Ornithological Institute Sempach "Bird-friendly construction with glass and light" from 2022.
Das Problem
Transparente Durchsichten wie beispielsweise bei Glasverbindern, Bushaltestellenhäuschen oder Eck-Verglasungen suggerieren den Vögeln eine freie Flugbahn zu dahinterliegenden Bereichen. Kommt es an Glasflächen zur lebensechten Spiegelung der umliegenden Vegetation oder des freien Himmels, kann dies dazu führen, dass Scheiben fälschlicherweise als potentieller Lebensraum angeflogen werden.
Häufig bleibt der Vogelschlag unentdeckt. Nur bei größeren Vogelarten kann man hin und wieder den Aufprall im Nachhinein, zum Beispiel durch einen Abdruck des Gefieders oder durch an der Scheibe klebende Federn, nachvollziehen. Aber auch die Tatsache, dass die Kadaver der toten Vögel häufig nach kurzer Zeit durch verschiedene Aasfresser abgetragen werden, trägt zu einer vermutlich hohen Dunkelziffer bei.
Die allseits bekannten und immer noch stark verbreiteten Greifvogelsilhouetten, die vereinzelt auf Scheiben angebracht werden, sind für einen Schutz gegen Vogelschlag wirkungslos und sollten daher nicht verwendet werden. Die Vögel erkennen in der starren Silhouette keine Bedrohung durch einen Fressfeind. Sie nehmen den Aufkleber zwar als Hindernis wahr, die umgebende Glasscheibe bleibt für die Vögel jedoch weiterhin unsichtbar.
Um Vogelschlag wirksam zu vermeiden, eignet sich das flächige Aufbringen von wirksamen Vogelschutzmustern. Eine Auflistung dieser Muster kann in der aktuellen Broschüre der schweizerischen Vogelschutzwarte Sempach „Vogelfreundliches Bauen mit Glas und Licht“ aus dem Jahr 2022 nachgeschlagen werden.
Found a bird strike victim?
The Lower Nature Conservation Authority of the City of Chemnitz is committed to ensuring that bird strike hotspots in the city area are protected. You can support us in this endeavour: Have you found a bird strike victim?Then document your find with a photo, the location and date of discovery and inform us by e-mail.
Thank you for your help!
Positive examples from Chemnitz
In Chemnitz, bird protection measures have already been implemented on glass at various locations. Chemnitz Hospital, for example, covered its glass connecting corridor with a bird protection film into which its own logo was integrated. Such creative solutions can also be suitable for effectively preventing bird strikes.Numerous bird strike incidents occurred on the glass connecting building of the former Technical Town Hall of the City of Chemnitz (Annaberger Straße 89/93) due to lifelike reflections and the view through the connecting building. The application of a suitable protective pattern will prevent birds from colliding with the pane in future.
