What birds are doing with your cigarette butts

Nicotine is one of nature's bug zappers. Seriously. Lots of plants have evolved to produce bug-repelling chemicals as part of their defense mechanisms and tobacco happens to be one of those plants.

So when city-dwelling birds use the fluffy, nicotine-soaked material from discarded cigarette butts to build their nests it might not be the unmitigated ecological disaster that most of us imagine when we hear that "birds are building nests out of discarded cigarette butts". Researchers at Mexico’s Autonomous University of Tlaxcala think the nicotine in the cigarettes might help keep chicks healthy — essentially serving as an urban substitute for the parasite-repelling plants the birds would have used in the wild.

At Culturing Science, Hannah Waters explains the idea...

But birds are actually quite fond of the chemicals found in some smelly plants, otherwise known as aromatics, from which “essential oils” are derived. Aromatic plants produce these chemicals to defend themselves against insects and other animals that would take them for food—but birds have their own use for them. Some nest-building species, including starlings and blue tits, regularly replenish their nests with fresh aromatics, and scientists hypothesize that the birds use these chemicals as parenting tools.

How would plant-derived chemicals help birds raise their chicks? It’s possible that the chemicals boost the immune systems or development of the chicks so that they survive better after they leave the nest; this is known as the “drug hypothesis.” Alternatively, the “nest protection” hypothesis suggests that the plant chemicals act as insecticides, driving parasites and other harmful insects from the nest.

Nicotine is an insecticide, although we don’t often think of it that way. Tobacco plants generate nicotine because it defends against herbivorous beetles that would otherwise devour the plants–which means a smoker’s buzz is caused by a plant’s chemical defense mechanism. Some remnants of that insecticide remains in cigarette butts left in city streets, which are then transported into bird nests.

Read the full story

A house sparrow stands near a cigarette butt in Mexico City. Photo Credit: © Víctor Argaez


  1. Great. Now we have a reason for smokers who litter to rationalize why they aren’t being complete assholes for doing so.

  2. “With the proliferation of e-cigarettes, urban bird populations have lost a valuable defense against nest-dwelling parasites. Chick mortality rates have risen by 4% a year for the past decade.” ~New York Times, Jun. 10 2028

  3. Another question would be whether the birds are selecting the butts.  It seems just as likely that they’re merely a significant percentage of the available nest-building material in cities.

  4. Smoking an insecticide?  As if the additives in cigarettes aren’t enough reason to quit: ammonia, acetone, benzene, formaldehyde, hydrogen cyanide and naphalene 

    1. Without defending cigarettes, though, most drugs we get from plants are toxic this way. Caffeine, THC, salicylic acid, even flavors like pepper or mint might be something we can appreciate, but become a huge overdose if you are the size of a bug or microbe.

      1. I thought capsaicin was a mammal repellent, and other phyla didn’t mind it at all.  Hence dousing your birdseed with cayenne for the squirrels. 

        1. I was thinking of peppery flavors from things like black pepper and mushrooms, which come from different substances. But while birds – which are in our phylum, by the way – don’t mind capsaicin, it possibly deters insects and definitely fungi.

          1. The reasoning I’ve heard, though I don’t have a citation on hand to back it up, is that mammals, which can digest pepper seeds, are repelled by the capsaicin while birds, which can’t digest them, don’t notice the capsaicin and end up spreading the seeds far and wide.

    2.  well i smoke, and i’ve never had bugs in my lungs.  irritation, sure, but not a single bug.

      1. The world is a funny place, and things unthinkable have way of suddenly turning common… Tobacco, just like many other drugs, has had its turns of fortune. The idea of “progress” the anti-smoking crusaders hold is a common illusion in history – I kinda suspect that may of the same “progressives” happily crusading along would sing a completely different tune if today wasn’t 2012 but 1942 when smoking really was “healthier than fascism”… Eggs used to be the big killer not 10 years ago, remember? There is no progress there is only change, sometimes it is useful to remind yourself of that.
        Cigarettes are harmful, of course they are. But you will forgive me and many out there for being cynical about this new fangled righteous anti-smoking crusade; jeez, as if the americans and their colonies had no idea cigarettes can kill you before http://en.wikipedia.org/wiki/Thank_You_for_Smoking_%28film%29 and now they’re all self-righteously over compensating all over the world.
        This generation will see marijuana legalized as a reaction to “war against drugs” just like the generation before overcompensated for the hippie apocalypse… Just like the generation after this one will see tobacco reintroduced to the “decent” society as a reaction to what is going on now. yawn.
        Historically, such prohibitions were always a sure sign of societal decadence, a gentrified ruling class… an aging population, to be blunt. Also, they usually heralded big status-quo changes, just like alcohol prohibition preceeded the great depression and finally the second world war… Socio-historically, today’s society’s obsession with “health” and “security” does not bode well for the next decade or two.

        1. We collectively took leave of our senses when we allowed the tobacco companies to redefine the smoking/anti-smoking debate in terms of freedom replacing older concepts of addiction such as vice as well as concepts of male versus female/juvenile space in addition to public versus private space. If male, female and juvenile are not restricted to men, women and children in particular then I think it is possible to return to a debate which while still full of tension does not succumb to the antagonism demanded of big tobacco and which can ultimately only produce an uneasy stalemate. Progress isn’t necessarily a straight line from A to B.

  5. Gee  Maggie i thought you were a environmentalist ?
    Cig have over 4000 chemicals added to them , they are allowed to do this because when the EPA hung their shingle in 1981 they grandfathered in every chemical in their boot  . All 65,000 of them without human or environmental impact study’s ! 

    Thats why smoking smells bad , thats why there is so much cancer . Thats why 1200 people die from smoking every day in USA , the 4000 chemicals in tobacco is why Nicotine gum and patches and vaccines don’t work . Here is a funny video breaking this down http://www.youtube.com/watch?v=K2dm049qlIw

    1. Not counting the many varieties of insect that have evolved to munch tobacco, which then concentrate the poisons in the inset’s tissue.

        1. Not effective against tobacco hornworm and various bugs that eat stuff deadlier than tobacco.

          1. I had sweet potato hornworms this year. Still not sure how I could pull three dozen four-inch caterpillars off one little hanging plant.

  6. In the barren parking lot of a local taco joint, there is a small traffic island where the only green is some sort of ugly electrical transformer, painted green to blend in with the nonexistent vegetation.  In the dusty ground are a series of holes about the size of tennis balls.  These are dust wallows for sparrows who I have seen lying on their backs with their feet sticking straight up while they happily beat their wings in the dust.

  7. When sparrows raised a brood in a nest on my windowsill I was amazed at the number of mites that were there.  I tried using a pyrethrin based insectiside but it didn’t seem to help much.  If only I’d known to use cigarette butts!

  8. Birds have long been observed rubbing odorous things on their plumage. The action is called “anting” and the OED’s earliest reference to it comes from 1936. According to The Observer, 1 March 1959, “tame birds will ant with matches or cigarette butts”. The SF/Fantasy writer Avram Davidson wrote a number of non-fictional essays on mythical creatures, and he suggested that the legend of the phoenix might be based on birds’ habits of snatching smouldering twigs.

    I also recall that there was a recent study showing that some  bird actually rubbed its feathers with poisonous insects or frogs, to deter predators. I can’t find the reference now, though.

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