Corrective and preventive measures
Every year, a vast number of birds suffer injuries or die from collisions with glass surfaces in urban and recreational settings. As building materials increasingly incorporate glass for aesthetic and functional reasons, the risk to avian life rises. Transparent walls can reflect the sky or vegetation, creating deadly traps that birds fail to perceive. This threat is especially acute near wetlands, lagoons, and other bird-rich habitats where visibility and proximity intensify the danger.
In Spain, paddle tennis courts have emerged as notable collision hazards. Estimates suggest that thousands of birds die yearly in regions like Catalonia, highlighting a broader pattern that alarms conservationists. Reports presented at recent birding events underscore how glass walls on these facilities can become invisible barriers for innumerable species, from small songbirds to insectivores and waterfowl.
At the Pablo de Olavide University of Seville, the paddle tennis courts sit in an ecologically rich zone close to shallow waters, making the layered glass a trap for many bird species. Local volunteers identified multiple dead birds along the bases of these windows, including species such as blackbirds, warblers, swallows, buntings, kingfishers, and hoopoes. The images and observations draw attention to an urgent need for mitigation, especially in areas with significant avian activity.
Photographs show the boats anchored or nets installed along court edges to prevent collisions. The effort by SEO/BirdLife volunteers, in collaboration with CEI-Cambio and the Sustainable Campus Delegation, led to the deployment of protective measures during 2022, coordinated with the University’s Healthy Campus and Sports initiatives. These measures include a network system of window treatments that disrupt the birds’ perception of glass without interfering with athletic training on the surrounding slopes. Similar approaches in other regions have demonstrated success, using vinyl strips or bird silhouette decals that are visible to birds but unobtrusive to players.
The approach combines practical design changes with a broader safety framework. For example, regional programs from the Generalitat Valenciana and the Rowing Federation have inspired similar implementations, underscoring that reducing bird fatalities does not have to compromise sports or activities. The key is to couple physical barriers with visible indicators and nightlife adjustments that minimize risk while preserving the facilities’ use.
The scale of the challenge
Understanding the scope begins with a clear picture of the threat. The Aves y Cristales campaign by SEO/BirdLife aims to raise awareness and knowledge about window collisions across Spain. The goal is to inform infrastructure managers, policymakers, and the public about the prevalence of this issue and to promote practical corrective and preventive actions. Even in the absence of official national statistics, research and field observations reveal a troubling pattern of bird deaths linked to glass surfaces in built environments. A detailed study in Tarragona recorded 193 fatalities across 17 species within a single building over a three-year span, illustrating the impact on migratory and resident birds alike.
Beyond NGO efforts, law enforcement and prosecutors have started to respond. Authorities, including prosecutors in environmental units, have begun to recognize collisions as potential animal welfare issues that may warrant action under revised criminal codes. Officials emphasize that responsible administrations should support preventive measures and promote initiatives to protect fauna. They note that awareness drives and voluntary compliance from facility operators play essential roles in reducing these incidents. The evidence shared by officials points to glass walls and road safety barriers as the most common sources of fatal collisions, urging a broader commitment to design and management that safeguards wildlife.
Addressing light pollution and legal considerations
Another dimension of the problem is artificial light. Night lighting can distract migratory birds, cause disorientation, and increase the risk of fatigue and predation. World Migratory Bird Day 2022 highlighted light pollution as a critical factor affecting avian survival. Organizations and researchers have documented how altered light regimes can shift migration routes, feeding behavior, and vocal communication. The United Nations has underscored the serious consequences of nighttime illumination for birds, urging communities to dim lights during the night and to adopt wildlife-friendly lighting practices where feasible.
Mounting evidence suggests that delayed or absent enforcement of wildlife protections complicates prosecution when birds suffer harm. Nonetheless, ongoing research and civic campaigns continue to push for stronger safeguards. Regional studies, including Cantabria’s ecocampus initiative in collaboration with SEO/BirdLife, demonstrate that practical, community-driven actions can reduce window-related deaths when tailored to local habitats and human activity patterns. These efforts combine education, signage, and targeted physical modifications to create safer environments for birds without sacrificing everyday use of buildings and courts.
In sum, the collision risk from glass and the broader issue of artificial lighting demand a coordinated response. Protective netting, window films, and bird-friendly decals are effective, scalable solutions that can be adapted to various facilities. Public and private stakeholders alike are encouraged to pursue these measures and to embed wildlife considerations into planning, design, and maintenance routines. The message is simple: awareness plus action equals fewer bird fatalities and healthier urban ecosystems for all. [attribution: SEO/BirdLife; CEI-Cambio; Sustainable Campus Delegation; Generalitat Valenciana; Rowing Federation]