The Naturalist's Corner

Complex Questions, One Simple Answer: We Need to Pick Up After Ourselves

by Andy Wood

This nesting box has one side removed to show nesting material chosen by the chickadee, which includes a layer of moss covered by shredded cigarette filters.

photo by Andy Wood

The above picture reveals a Carolina Chickadee (Poecile carolinensis) nest in a rural part of Pender County, where one would expect to see few cigarette filters. And yet, the nest includes frayed filters (far right front), along with bits of fibrous insulation, fresh moss, pine straw, mammal hair and other natural materials. This mixture of anthropogenic (human origin) and nature’s materials is common with chickadee nests. However, after witnessing several chickadee nest failures over the past several years, I have begun wondering if there is a connection between chickadee nestling survival and the presence of cigarette filters; owing to the fact that used filters contain large amounts of nicotine, a toxic compound with a long history as an effective insect and mite pesticide.

I’ve long been interested in nicotine as a pesticide, probably because my father conducted research in the late 1950s to prove spider mites develop resistance to nicotine at the genetic level.

I recall as a kid, an experiment one of my brothers conducted on mosquito larvae in a jar of water. It was a simple demonstration to show why I should not smoke cigarettes. He blew a bit of smoke into the jar, closed it up and we watched in rapt interest as the larvae quickly died. My brother, now a curator with a New England historic museum, recently told me that he sometimes finds bits of tobacco inside pockets and between layers of old fabric artifacts. In the 18th century, tobacco was placed in folded fabrics during storage as a deterrent to moths and other fabric-eating insects. “Not as sweet as lavender, but does the job good as cedar,” he says.

Nicotine as an effective poison prompted an aquatic scientist in the 1990s to examine the potential biohazard of used cigarette filters in freshwater ecosystems. The research involved placing used cigarette butts in different volumes of water containing live Daphnia, Crustaceans related to shrimp and lobsters. The study found that, when soaked in two gallons of water, enough nicotine and other toxins leached out of one used cigarette filter to kill Daphnia outright. Because small fishes and other aquatic animals depend on Daphnia for food, this easily replicated study proves that improperly discarded cigarette filters pose a threat to ecosystem health.

Getting back to the chickadee nest containing used cigarette filters, I wonder if there is a connection between the presence of used filters and resulting egg and nestling mortality. I have seen nestling chickadees fledge in seeming good health despite having been raised in a nest with used cigarettes, but I have also found chickadee nests with a full clutch of dead eggs nestled in a fluffy cup of shredded cigarette filters. So this is an issue that clearly needs more investigating.

There may even be a selective advantage for chickadees living with cigarette filters: if the nicotine acts as a pesticide to bird lice, mites and ticks without killing the chicks or parents, their overall health may be enhanced, but there is likely a fine line between “the treatment being worse than the ailment.”

Chickadees are opportunistic nest-builders, and will incorporate anything they find into their homes.

The scientific process is essential to help answer such complex questions. We know from centuries of use as a pesticide that nicotine is poisonous to wildlife, and to humans. We know from recent studies of used cigarette filters in water that filter contents are harmful to ecosystem health, beginning near the bottom of the food pyramid, upon which higher life forms depend.

The first Earth Day, celebrated in 1970, drew attention to air and water pollution, endangered species, and litter. These issues are still with us. With the expansion of plastics as a replacement for paper and glass containers, the lifespan of today’s litter far outlasts the people who generate it. Cigarette filters may seem inconsequential until you consider some 360 billion cigarettes are smoked in this country each year. Over five trillion cigarettes are smoked worldwide. Today, cigarette filters are the most common item collected during organized beach cleanups.

Discarded cigarette filters may seem a trivial subject for discussion in light of our other global challenges—including climate change, energy issues, water shortage, wars and social unrest. But there are many acts each one of us can perform daily to help improve our global condition. Paying attention to the little things, like improperly discarded cigarette filters, can help us ensure we are not overloading our planet.

Andy Wood is the Director of Coastal Plain Conservation Group, and is author of Backyard Carolina.

Proceeds from the book support his work to protect two critically endangered species of freshwater snails, both endemic to southeast North Carolina. Learn more about his work at coastalplainconservationgroup.org.