Adaptive City Birds Are Using Cigarette Butts in Nests to Keep Away Mites

Countless studies over the past few decades have definitively shown that cigarettes are bad for you. That’s probably not news to you. But what is news is that cigarettes may actually be good for birds.

If you imagine a Northern Cardinal with a large lit cigarette in its mouth, you’re way off. Instead, new research suggests that cigarette-lined nests have a positive effect on chicks for two reasons.

One, nests with cigarette butts have a significantly smaller occurrence of nasty nest mites because there are traces of insecticide in the chemicals. Two, cigarette butts are amazingly good insulators for nests.

This finding shouldn’t be too shocking for some bird lovers. Birds are known to use strange objects—such as balls of human hair, animal fur, dental floss and spiderwebs—to build their nests. Some also use chemical-emitting plants in their nests to reduce parasites, which is basically what they’re doing with the butts.

Constantino Macías Garcia said that toxicity levels were unlikely to reach dangerous levels, but it’s hard to completely discount it until more studies are done.

Finally, it should be noted that I don’t recommend tossing old cigarette butts on the ground for the sake of birds.