Not an art installation: School uses CDs to minimise bird collisions

SINGAPORE – The strings of CDs hanging from the windows of the staffroom pantry at Commonwealth Secondary School may seem like a pretty art installation to passers-by, but they are actually a biology teacher’s effort to minimise bird collisions. 

Mr Jacob Tan, 41, and his colleagues noticed a pair of collared kingfishers repeatedly flying into the reflective windows like a bolt from the blue. 

Highly recognisable by their turquoise-blue back and wings, the kingfishers had begun frequently perching on the trees opposite the staffroom pantry on the third floor since April. They often flew right at the windows, mistaking the reflections for greenery.

After counting 10 collisions in an hour, Mr Tan began exploring ways to alert the birds to the seemingly invisible barrier ahead, from opening the windows to covering them with newspaper. “The whole point is to break the reflection of the greenery,” he said.

Eventually, he settled on using CDs as a makeshift measure until the school installs a more permanent solution, such as non-reflective stickers.

He and two other teachers collected unwanted CDs from their colleagues, which they strung up outside the windows.

When he first began the “art installation”, the number of bird collisions dropped to around two per day, said Mr Tan. More CDs were added until the problem was eliminated.

Around 80 CDs were hung up, with more on standby in case bird collisions happen elsewhere around the school.

“My colleagues will also alert me if they witness a collision,” he said. “We’re getting everyone involved in contributing these CDs because the teachers want something to be done. We felt that it was pitiful to see such a beautiful bird (going through this).”

Commonwealth Secondary School was one of the pilot schools under the Ministry of Education’s Eco Stewardship Programme announced in March 2021, which aims to foster environmental stewardship among students. 

The school had previously installed mitigation measures, such as non-reflective decals, in other areas where bird collisions had occurred.

For instance, a male jambu fruit dove, a near-threatened species that is native to South-east Asia, died after flying into a reflective window of the school’s computer laboratory in 2018. The school installed frosted decals on the lab’s windows after that. 

The non-reflective stickers helped to put an end to bird collisions at those sites, said Mr Tan.

“We want to be intentional in raising the next generation to be stewards for the environment and to create a safe haven for wildlife,” he said.

Student Nadia Nandasina, who is a member of the school’s eco-club, said seeing her school’s sustainability efforts gave her a sense of pride. 

“I didn’t know that a school can do so many things about the environment,” said the 14-year-old.

The school’s principal, Mr Jeremy Ang, said the school hopes to enable both students and staff to coexist harmoniously with nature and the wildlife that they encounter on campus.

He said: “Once a relationship with nature and the environment is nurtured, it will be a good starting point for conversation on conservation.”

Dr Tan Yen Yi, assistant senior curator of birds at NUS’ Lee Kong Chian Natural History Museum (LKCNHM), said the hanging of CDs can help prevent birds from crashing into reflective and transparent facades by disrupting reflections.

“This is a creative and low-cost solution (to bird collisions) that I am hearing about for the first time. In theory, it is a good makeshift measure that should do the trick, even if unconventional,” said Dr Tan.

She added that retrofitting buildings with bird-safe measures often poses the issue of aesthetics and functionality, as windows are meant to provide clear views for people inside the building.

Surfaces that are reflective and transparent are poorly perceived by birds, and they often suffer some form of physical trauma after crashing into man-made structures such as buildings, explained Dr Tan. 

“These surfaces create an illusion of continuity of the natural environment, either by reflecting the sky and nearby vegetation, or by being a completely invisible barrier – much like how walking into clear glass doors (happens to some) of us, except birds do that at full sprint,” she said.

Dr Tan, who runs LKCNHM’s Dead Bird Hotline and logs reports of dead birds around Singapore, estimated that up to 90 per cent of fatality reports received in 2025 were due to collisions, making it the leading cause of mortality among cases reported to the hotline based on eyewitness reports and circumstantial evidence.

Measures that make surfaces more visible for birds, such as drawing the curtains and placing plants away from windows, can help to reduce bird collisions, she added.

Other schools around Singapore have also been engaging in various sustainability efforts. 

In 2025, Nanyang Technological University students successfully raised funds to retrofit the School of Art, Design and Media with decals after seeing frequent cases of avian visitors hurting themselves or dying when they flew into the glass facade of the four-storey building.

Meanwhile, Naval Base Primary School runs a Wellness Garden equipped with a solar-powered hydroponics system, where students grow vegetables and learn about food security and renewable energy. 

The public can call the ACRES Wildlife Rescue Hotline on 9783-7782 if they find a wild animal in distress. They can also contact the National Parks Board’s Animal Response Centre on 1800-476-1600 to report wildlife in distress, or make inquiries and feedback on animal-related matters.

For dead bird reporting, members of the public can message LKCNHM’s Dead Bird Hotline, with a photo and location of the bird, via WhatsApp on 9876-4997 or @deadbirdhotline via Telegram.