In the column “Since You Asked” in every issue of BirdWatching, Contributing Editor Julie Craves answers readers’ questions about birds and bird behavior. Here is a question from our October 2016 issue:
My wife has turned our property into a bird paradise, but our yard has many dandelions, crabgrass, clover, and other weeds because she will not let me treat the lawn with weed killer. Are these chemicals really harmful to birds? – Ralph Craig, Tipp City, Ohio
Yes, chemicals used for lawn care can harm not only birds but also other wild animals, pets, even humans. Birds are exposed by various means, including skin contact, direct ingestion of contaminated insects or seeds, drinking tainted water, and breathing toxic vapors.
The active ingredients are tested for toxicity, but the goal of the required tests is typically to determine harmful dosages for some sample animal, often a rat or rabbit. The tests do not take into account different species or long-term or sub-lethal effects, and similar testing is usually not required for the other (“inert”) ingredients, which may make up most of the product.
According to the U.S. Environmental Protection Agency, over 200 chemicals are used for home lawn care, and 66 million pounds of just the products’ active ingredients is applied in home and garden settings annually. About two-thirds of the total are herbicides. Keep in mind that killing weeds eliminates host plants for insects (and flowers for pollinators), and that fewer insects means less of the food that birds need to raise their young.
Their individual toxicity aside, no testing is required to determine the effects caused when the products are used together or when they mix in the environment with other pollutants or even naturally occurring elements. The number of potential combinations is staggering, and their effects are extremely difficult to test. I’m committed to not taking part in this grand experiment, even if it means an unconventional, wild-looking yard. Won’t you join me? – Julie Craves
About Julie Craves
Julie is supervisor of avian research at the Rouge River Bird Observatory at the University of Michigan Dearborn and a research associate at the university’s Environmental Interpretive Center. She writes about her research on the blog Net Results, and she maintains the website Coffee & Conservation, a thorough resource on where coffee comes from and its impact on wild birds.
New to birdwatching?
Sign up for our free e-newsletter to receive news, photos of birds, attracting and ID tips, descriptions of birding hotspots, and more delivered to your inbox every other week. Sign up now.