Test your knowledge about birds and bird-friendly glass solutions with this five-minute quiz (8 questions).
Your Answer [field_1680507682126_107]
Explanation: Birds are an essential element of the ecosystem, providing hundreds of billions of dollars in ecological services and economic benefits in North America.1 However, it is estimated that in the last 50 years the overall population of birds in the US & Canada has declined by nearly 30%,2 and building collision is one of the top sources of avian mortality caused by human activities.3 The architectural field has a new challenge of finding creative ways to reduce its impact on bird populations while balancing all of the other benefits that glass brings to humans — like visually connecting us to the outdoors, providing natural light to help improve well-being, thermal comfort and productivity for building occupants. Sources 1 “Evidence, consequences, and angle of strike of bird-window collisions” by Daniel Klem, Jr; Peter G. Saenger; Brandon P.Brogle https://meridian.allenpress.com/wjo/article-abstract/136/1/113/498924/Evidence-consequences-and-angle-of-strike-of-bird 2 “Analysis: The Economic Value Of Birds”, by Çağan H. Şekercioğlu, June 12, 2017; https://www.allaboutbirds.org/news/analysis-the-economic-value-of-birds/ 3 “Vanishing: More Than 1 In 4 Birds Has Disappeared In The Last 50 Years”, by Gustaven Axelson, September 19, 2019; https://www.allaboutbirds.org/news/vanishing-1-in-4-birds-gone/ 4 “Bird – building collisions in the United States: Estimates of annual mortality and species vulnerability, by Scott R.Loss, Tom Will, Sara S. Loss, Peter P. Marra; https://academic.oup.com/condor/article/116/1/8/5153098?login=false
Sources 1 “Evidence, consequences, and angle of strike of bird-window collisions” by Daniel Klem, Jr; Peter G. Saenger; Brandon P.Brogle https://meridian.allenpress.com/wjo/article-abstract/136/1/113/498924/Evidence-consequences-and-angle-of-strike-of-bird
2 “Analysis: The Economic Value Of Birds”, by Çağan H. Şekercioğlu, June 12, 2017; https://www.allaboutbirds.org/news/analysis-the-economic-value-of-birds/
3 “Vanishing: More Than 1 In 4 Birds Has Disappeared In The Last 50 Years”, by Gustaven Axelson, September 19, 2019; https://www.allaboutbirds.org/news/vanishing-1-in-4-birds-gone/
4 “Bird – building collisions in the United States: Estimates of annual mortality and species vulnerability, by Scott R.Loss, Tom Will, Sara S. Loss, Peter P. Marra; https://academic.oup.com/condor/article/116/1/8/5153098?login=false
Explanation: The birds may perceive a tree’s reflection onto the glass as another real tree. The inability to differentiate between reflection and reality can lead to bird strikes. While humans can perceive edges or other visual breaks in glass and recognize it as a barrier, the American Bird Conservancy (ABC) suggests that birds may not have this perception.
[Question 2/8] Why is glass reflectivity one of the primary causes of bird collisions? Your Answer: [field_1680530367744_25] CORRECT ANSWER: Birds mistake reflections of a building’s surroundings for extensions of their habitat
EXPLANATION: Birds may strike transparent windows when trying to fly to inviting elements on the other side, such as indoor plants, potential perches and food or water sources. This is why products with visible deterrents, or those incorporating a UV signal, can be effective in helping to reduce birds colliding with glass on buildings.
[Question 3/8] Views through glass windows are also a primary cause of bird collisions. Why? Your Answer: [field_1680531494785_39] CORRECT ANSWER: Both
EXPLANATION: 4- to 11-storey buildings in the suburbs account for +/- 56% of total bird-window collisions, against +/- 44% for 1- to 3-storey buildings, and less than 1% for +12-storey buildings*. Anywhere birds are, such accidents can happen – the more birds, the more collisions. And there are a lot more birds near suburban buildings than in cities because the habitat these animals like is much more abundant outside of cities.
*Source: Bird-building collisions in the United States: Estimates of annual mortality and species vulnerability. By Scott R. Loss, Tom Will, Sara S. Loss, Peter P. Marra (Bird–building collisions in the United States: Estimates of annual mortality and species vulnerability (bioone.org)
[Question 4/8] What type of buildings account for the higher percentage of total bird-window collisions? Your Answer: [field_1680531978383_53] CORRECT ANSWER: Low-slung buildings in the suburbs
EXPLANATION: The glazing solution to be tested is placed at the end of a flight tunnel, next to a standard glass. When attempting to leave the tunnel, the birds need to choose between one or the other option. The researchers count the number of birds that fly toward the control sample and the number that fly toward the bird-friendly deterrent glass (a net safely prevents the birds from hitting the glass). The transparency test (ONR test) at the Hohenau-Ringelsdorf Biological Station in Austria provides a percentage of approach to the bird-friendly glass that was tested which allows the classification of the solution into 4 categories (Highly effective, somewhat effective, barely effective, and not effective). The American Bird Conservancy (ABC) tunnel test provides a Threat Factor (TF) score. The ABC considers a TF ≤ 30 to be bird friendly, corresponding to a reduction of collisions of at least 50% under real world conditions. Some municipalities use the ABC test to define regulations. New York City, for example, requires a TF of ≤ 25, while other municipalities like Toronto use prescriptive design guidelines. It’s important to note that different research institutes and stakeholders may have different thresholds for what is considered acceptable performance. Contact us for more information on your region’s code requirements
[Question 5/8] How is the effectiveness of bird-friendly glass solutions evaluated by the Hohenau-Ringelsdorf Biological Station, in Austria, and by the American Bird Conservancy (ABC)? Your Answer: [field_1680532403343_67] CORRECT ANSWER: Birds are placed in a tunnel where they can fly toward two glass options at the end
EXPLANATION: Visual contrast and spacing determines effectiveness, not coverage. Selecting the densest pattern is not necessary.
[Question 6/8] Which one of these patterns is the most effective at protecting birds from collisions? Your Answer: [field_1680535035769_65] CORRECT ANSWER: The large dots pattern with low % coverage
Explanation: Visual contrast and spacing determines effectiveness, not coverage. Selecting the densest pattern is not necessary.
EXPLANATION: From inside the building, the visibility of a bird deterrent depends on the technology, the pattern design and color, which define how much it will contrast with the visual environment, especially the brightness and complexity of the scenery outside. Light-colored patterns are usually less visible against the backdrop of a blue sky, but if the surrounding view is complex – like a busy cityscape or a leafy forest – a dark-colored pattern can be less visible from inside the building than a light-colored pattern.
[Question 7/8] A light-colored pattern is less visible to building occupants looking inside-out than a dark-colored pattern. Your Answer: [field_1680536230521_93] CORRECT ANSWER: It depends
Explanation: From inside the building, the visibility of a bird deterrent depends on the technology, the pattern design and color, which define how much it will contrast with the visual environment, especially the brightness and complexity of the scenery outside. Light-colored patterns are usually less visible against the backdrop of a blue sky, but if the surrounding view is complex – like a busy cityscape or a leafy forest – a dark-colored pattern can be less visible from inside the building than a light-colored pattern.
EXPLANATION: The effectiveness of stickers, just like any bird deterrence solution, depends on a number of factors including: the brightness, inside and out; the complexity of the scenery, reflected and transmitted; the amount of visual contrast created by the deterrent; which surface of the glass the pattern is applied to; the distance between elements of the bird deterrent. The distance between the elements of the pattern is often an issue, as stickers are typically applied randomly and in small quantities on a window, while they should be spread out across the entire glazing surface to avoid giving birds the illusion that they have enough space to fly between the elements.
[Question 8/8] Stickers and decals, commonly considered for retrofits and residential windows, is an effective way to help prevent birds from colliding with glass. Your Answer: [field_1680536649694_109] CORRECT ANSWER: Like any deterrent technology, it depends on many factors
Explanation: The effectiveness of stickers, just like any bird deterrence solution, depends on a number of factors including: the brightness, inside and out; the complexity of the scenery, reflected and transmitted; the amount of visual contrast created by the deterrent; which surface of the glass the pattern is applied to; the distance between elements of the bird deterrent. The distance between the elements of the pattern is often an issue, as stickers are typically applied randomly and in small quantities on a window, while they should be spread out across the entire glazing surface to avoid giving birds the illusion that they have enough space to fly between the elements.
