Ultraviolet patterns can make window glass visible to birds, thus preventing fatal collisions. However, it has now been shown that such windows are not likely to work for all species, but only for birds like small passerines, gulls and parrots, who have a special type of colour vision. For birds of prey, geese, pigeons and crows, these patterns should be difficult to detect. These conclusions appear today in an article by Olle Håstad and Anders Ödeen in PeerJ.
Billions of birds are killed in window collisions every year. This is one of the most important human sources of avian mortality. A popular and effective remedy is to apply stickers showing the silhouettes of birds of prey to windows. Birds avoid colliding with these stickers but one problem remains: that the birds collide with the glass in between the stickers instead. To avoid having to cover whole windows with stickers, glass must be made visible to birds in some other, and less obtrusive, way.
As most birds can see ultraviolet light, which is invisible to humans, one solution is to mark the glass with ultraviolet reflective or absorbing patterns. Glass panes containing such ultraviolet absorbing patterns are currently commercially available. Elegant as this remedy may seem at first glance, field tests of UV-marked window panes have yielded mixed results. In a study published on October 9 in the open access journal PeerJ, Dr Olle Håstad at the Swedish University of Agricultural Sciences and Dr Anders Ödeen at Uppsala University show that ultraviolet window markings indeed have the potential to be effective deterrents. However, since birds differ strongly in how well they see ultraviolet light, the markings should only be visible to those bird species that have the right type of colour vision.
Håstad and Ödeen calculated how visible ultraviolet anti-collision markings are by using a physiological model of avian colour vision. They conclude that ultraviolet markings may be clearly visible under a range of lighting conditions, but only to birds with the so called UVS type of ultraviolet vision. Such birds include for example many small perching birds, gulls and parrots.
To species with the other (VS) type of colour vision, such as birds of prey, geese and ducks, pigeons and crows, ultraviolet markings should not be visible under most practical circumstances. To be visible to these birds, the patterns would have to produce virtually perfect contrasts and be viewed against a scene with low colour variation but a high ultraviolet content, such as a clear blue sky.
Olle Håstad & Anders Ödeen. 2014. A vision physiological estimation of ultraviolet window marking visibility to birds. PeerJ 2:e621.
Image: Sky reflected in the windows of a high-rise building in central Gothenburg, Sweden. Photo: Anders Ödeen
Press image (may be published without charge in articles about these findings, please acknowledge the photographer)
Olle Håstad, PhD
Dept of Anatomy, Physiology and Biochemistry
Swedish University of Agricultural Sciences, Uppsala, Sweden
+46 (0)70 810 64 73, firstname.lastname@example.org
Pressofficer: David Stephansson: +46-725 11 69 90 or David.Stephansson@slu.se
Ingemar Björklund | idw - Informationsdienst Wissenschaft
Smart buildings through innovative membrane roofs and façades
31.08.2017 | Fraunhofer-Institut für Organische Elektronik, Elektronenstrahl- und Plasmatechnik FEP
Concrete from wood
05.07.2017 | Schweizerischer Nationalfonds SNF
University of Maryland researchers contribute to historic detection of gravitational waves and light created by event
On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...
Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.
Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....
Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).
When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...
Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.
How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...
Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.
It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...
17.10.2017 | Event News
10.10.2017 | Event News
10.10.2017 | Event News
18.10.2017 | Materials Sciences
18.10.2017 | Physics and Astronomy
18.10.2017 | Physics and Astronomy