How birds die fighting their own image on windows

How birds die fighting their own image on windows

Jasjeev.Gandhiok@timesgroup.com

New Delhi:13.02.2021 

Reflective glass panes may up the style of a building, but it is dangerous for birds, especially for nonurban avian species. For one, their own reflection in the window confuses the birds and causes them to peck aggressively at the glass to attack the ‘enemy’ bird, particularly during nesting season. The birds injure themselves, even die at times. Ornithologists say this phenomenon is becoming common as more buildings now use reflective windows that allow one-way view of the outside.

Faiyaz Khudsar, scientist in charge at the Yamuna Biodiversity Park, said that many birds perceive the reflections in the windows as hostile birds. “At the Biodiversity Park itself, we see a lot of babblers pecking at their own reflections in the windows,” said Khudsar. “However, more than regular windows, reflective windows and those using glass films pose a higher risk to the birds.”

A 2014 study established that one billion birds died from window strikes every year in the United States. The study had analysed the behaviour of the golden-winged warbler, painted bunting, Canada warbler, wood thrush and the Kentucky warbler.

Experts explained that birds establishing their territory or nesting show these aggressive characteristics, and mistake their own reflections for other avians that need to be driven away from the spot. Dr Surya Prakash, zoologist at Jawaharlal Nehru University, pointed out that while birds like pigeons and crows are less affected by the reflections, species living in denser forested patches adjoining urban settlements often mistake the images for enemy birds.

“This is often the case with jungle babblers, woodpeckers and drongos. In some cases, they have died trying to defend their territory,” said Prakash. “They are especially territorial during the nesting season. Males are protective of their territory and defend the female and the chicks from the presumed male in the reflection. Similarly, female birds may think it’s another female bird trying to harm the chicks.”

The capacity to adapt varies from species to species. “We have seen a peregrine falcon nesting atop a reflective building near Okhla Bird Sanctuary for several years,” revealed Prakash.

Nadeem Shehzad, who runs a veterinary hospital for raptors in north Delhi, disclosed having received many birds injured in head-on collisions with glass panes. “It used to be common abroad, but with more people installing reflective windows, cases are rising here too,” said Shehzad. “Shikras, in particular, fly low and often injure themselves in this manner. Birds can actually die from the head-on collisions.”

DANGEROUS ONE VIEW: Their own reflection confuses birds, and causes them to peck aggressivel