Smoking has been proven to harm the health of smokers and those around them, to age skin, and has been linked to many other negative effects. Which makes it that much harder for smokers to come up with good excuses to keep up their nicotine habit. To say nothing of rationalizing flicking their litter away after each fix.
Science to the Smoker's RescueNow science offers an answer to the smokers' conundrum: we smoke (and litter) to help the birds!
Birds often collect materials such as pet fur or feathers which offer good insulating properties -- as do the cellulose acetate fibers in cigarette filters -- to line their nests. But scientists studying the propensity of birds to collect cigarette butts suspect the birds may benefit from the nicotine and other toxins which saturate the filter fibers.
In an article published in Biology Letters, Monserrat Suárez-Rodríguez, Isabel López-Rull and Constantino Macías Garcia studied the nesting sites of house sparrows and house finches. They set thermal traps for ectoparasites (mites) in the nesting areas of birds breeding at the National University of Mexico. They fitted the traps with smoked or unsmoked (control) filters from a single brand of cigarettes.
Additionally, as soon as the fledglings left their nests, the nests themselves were collected and the number of parasites associated with each nest was measured, along with the number of used cigarette butts incorporated in the nests.
Smoking to the Birds' Rescue?The scientists showed that the traps with smoke cigarette filters attracted significantly fewer mites (60% fewer when averaged over nests which were empty, held eggs, or were populated with chicks). They also showed that the number of mites found in the nests decreased as the number of cigarette butts incorporated in nesting materials increased.
The report suggests more research is needed to determine if the cigarette butts are selected by birds for their pesticidal effects. Such selection, probably based on the smell of the dirty butt, would mirror selection of certain plant materials that can deter parasites by nesting birds -- a known phenomenon in wild bird populations.
One Question RemainsIn order to demonstrate that the use of cigarette butts constitutes natural self-medication by the birds, one other aspect must also be proven: that the use of the cigarettes by birds increases the birds' health (fitness, to use the biologist's term). Who wants to place bets: are the benefits of parasite evasion enough to offset the toxic effects of nicotine on the young birds as they grow up in their cigarette butt nests?
Tongue Out of CheekStudying the behavior of urban animals, especially changes in wild patterns of behavior as city critters take advantage of people's habitats, answers important questions in conservation biology.
But even if butts turn out to be excellent building materials for bird architects, humans can hardly stand behind that benefit as an excuse for the tons of toxic cigarette butt litter that threaten the natural environment.
If you find the pleasure of nicotine to be worth the risks, enjoy your smoke -- then put the butt in the garbage where it belongs. Better that the birds find another way.