Whenever the subject of pesticides comes up, it’s easy to point a finger at farmers. But we homeowners, with our manicured lawns and exotic flower gardens, have nothing to be smug about. Each year we pour approximately 136 million pounds of pesticides on our homes, lawns, and gardens, which amounts to three times more per acre than the average farmer applies. In fact, most of the wildlife pesticide poisonings reported to the U.S. Environmental Protection Agency result from home use. According to the EPA’s wildlife mortality incident database, just three of the chemicals commonly used in the garden and home–diazinon, chlorpyrifos, and brodifacoum–kill thousands of birds each year.
In the early 1990s two California metropolitan areas–the City of Davis and central Contra Costa County–discovered levels of diazinon and chlorpyrifos, high enough to harm aquatic organisms, in their storm-water systems. After testing, officials in both places determined that the greatest source of pesticides in local surface waters was single-family homes.
“Chlorpyrifos is very prevalent,” says Jacques DeBra, pollution prevention program manager with the City of Davis Public Works Department. “It’s like mowing the lawn. People have been using it for years. It’s hard to get them to look at alternatives.”
Oddly enough, both diazinon and chlorpyrifos (see chart, below), because of their high toxicity to birds and wildlife, meet the Environmental Protection Agency’s criteria for “restricted use,” which means that they require a permit and training to purchase. The Rachel Carson Council petitioned the EPA to upgrade the label for diazinon in 1997 and last year requested that the use of chlorpyrifos be banned around dwellings.
When and where pesticides are used is also critical. The majority of bird kills occur in February in southern states, where the early growing season and spring migration coincide, followed by March, May, and April, the months when birds as well as gardeners are on the move. Birds with the highest risk of exposure include waterfowl, such as brant geese, which have been known to eat large quantities of pesticide-treated foliage. Seed-eating songbirds, because they are attracted to pesticide granules and treated seeds, are also at high risk. A third hard-hit group includes scavengers as well as raptors such as red-tailed hawks or great-horned owls, which often feed on pesticide-poisoned prey.
To help reduce the pesticide threat, the National Audubon Society has launched BirdCast, a cooperative program with Cornell University’s Laboratory of Ornithology, Clemson University’s Radar Ornithology Laboratory, the Academy of Natural Sciences, and Geo-Marine, a private engineering firm. Employing state-of-the-art NEXRAD radar and reports from citizen-scientists, the program will use the Internet to post detailed radar images of bird migrations in the Philadelphia, Baltimore, and Washington, D.C., metropolitan areas.
The site (www.BirdSource.org/Birdcast/) will tell what pesticides to avoid during peak migrations and how to make your backyard more hospitable to birds. The site will also provide information on local pest threats and the safest ways to manage them. More important, thousands of birders will get the chance to contribute to the project by verifying the species that visit their backyards or favorite birding spots. They will then be able to enter their sightings into a database and see running tallies of species almost instantly.
Kicking the pesticide habit isn’t mission impossible. Just ask one of the nation’s more than 6,000 certified organic farmers, or the City of Arcata, California, which, after 15 years of using nontoxic pest controls, banned all pesticide use on city property as of this past February.