Cats are killing India’s birds. Are we paying attention?

Birds in India are facing poor conditions due to many factors, including cats. Studies have found cats to be the "single greatest source of anthropogenic mortality" for birds and mammals in the US. Ecologist Monica Kaushik has studied cats' hunting habits in Dehradun and found pet cats hunt birds the most. Cats maintain a 'landscape of fear' and their saliva contains bacteria lethal to birds. Debate on the proper way to deal with cats has spiralled in the West, but India has nearly no data.

On the basis of 30 million observations by more than 30,000 birdwatchers, the ‘State of Indian Birds 2023’ exercise recently concluded that birds in India are faring poorly. Among many factors, the report acknowledged a silent bird-killer lurking in India’s urban areas: cats.

Cats may seem to pale in the shadow of the threats posed by forest degradation, industrialisation, and climate change, but conservationists know better. In the U.S. alone, free-ranging domestic cats have been estimated to kill billions of birds every year.

One study found that cats may be the “single greatest source of anthropogenic mortality” for birds and mammals in the U.S. Worldwide, free-ranging domestic cats have caused or contributed to dozens of extinctions of bird species recorded in the IUCN Red List.

Disturbed by the lack of India-specific data on the issue, ecologist Monica Kaushik has been studying the hunting habits of free-ranging domestic cats on urban birds in Dehradun, a city that has 590 of the 1,359 species of birds recorded in the country. She found in a survey that pet cats hunted birds the most, followed by reptiles, insects, rodents, and amphibians.

While free-ranging dogs also harm wildlife, Dr. Kaushik said cats have retained the instinct to hunt through many years of domestication, even if they don’t need the skill anymore. Cats also can do something dogs can’t: “They can climb, so they can reach habitats such as the nests of canopy-dwellers.”

Cat saliva is also more likely to contain bacteria (Pasteurella multocida) that are lethal to birds. So if the direct impact of an attack doesn’t kill them, the bacteria will. Former urban wildlife rescuer Abhisheka Krishnagopal suspected that this could be why most cat-attacked birds reported to her didn’t survive the trip to a treatment centre.

Cats also maintain a ‘landscape of fear’. “This means that when cats are known to be in a particular area, the bird would avoid foraging or nesting there,” Dr. Kaushik explained. “They end up investing time and energy to be extra vigilant and to find alternative areas. This affects them individually and on a population level.”