Why Are Birds So Obsessed With Cigarettes?

Humans aren’t doing a great job of cleaning up the environmental mess we’ve created. So, some birds are adapting to our pollution in ways that are simultaneously clever, sad, and unsettling. For instance, some birds are building nests out of cigarette butts.

As reported by the New York Times, based on a study published in the journal Animal Behavior, birds from all over the world, from the Galápagos to New Zealand, are weaving discarded cigarette butts into their homes. Sometimes, they’re even nesting directly in actual, literal ashtrays.

Researchers in Poland found that blue tits, a bird common across Europe, seemed to like leaving cigarette butts in their nests. Why? Because they provide a kind of natural/completely unnatural pesticide, with the nicotine and heavy metals a human drags into the butts that seem to naturally repel parasites.

Are Birds Developing an Addiction to Cigarettes?

To test this theory in a lab setting to see how effective cigarette butts can be at repelling insect invaders, the scientists set up some controlled experiments where they put cigarette butts into some nests while leaving others untreated or completely sterilized. The results weren’t dramatic, a little on the subtle side, but they revealed quite a bit. Nests with butts had slightly fewer parasites, like fleas and blowflies, than the nicotine-free nests.

The baby birds raised in those nests filled with cigarette butts and the sterile tests were both noticeably healthier than those in the untreated nests, according to blood work conducted by the researchers. This suggests that parasites play a big role in early bird development.

Members of separate research teams looking into the weaving of cigarette butts into nests found that some birds will even respond dynamically, adding more cigarette butt material when they detect a rise in parasite levels. Finches and sparrows in Mexico City, for instance, have their own unique spin on the practice by tearing the butts apart and spreading the fibers throughout the nest for better coverage.  

There is a big potential downside to all of this, and you can probably already guess it: chicks in direct contact with nicotine have shown signs of genetic damage. The long-term effects of that are unclear, but it’s definitely something researchers will keep an eye on in the years to come.

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