Pesticides and Birds

Herbicides, often used near roots or sprayed directly onto plants to remove invasive species or weeds, can harm birds by reducing food resources and contaminating habitat. Bird species that rely on berries and seeds like the Cedar Waxwing are at risk for herbicide consumption. Unlike humans, birds cannot read signs warning of herbicide application and may ingest food from a recently sprayed plant.

Additionally, herbicides pollute bodies of water such as lakes and streams. Most commonly, they enter surface water in runoff or leachate. The runoff from herbicides degrades the surrounding vegetation that provides habitat and food for many bird species. The US EPA has stated that “herbicides may contribute to other stressors (e.g., instream habitat alteration via riparian devegetation),” listing further impacts on ecosystems birds rely on. Though acute toxicity to animals is likely only when they are applied in sufficient quanities, several types of herbicides bioaccumulated in fish populations, which are then eaten by  birds like gulls, osprey, and terns.

Osprey/Jim Verhagen/Audubon Photography Awards

Herbicide-free solutions

• Do some research on “weeds” you find: they may not be weeds at all. Resist the initial urge to apply herbicides. Rather, attempt to pull, replant, or manually discard unwanted plants. The Washington State Noxious Weed Control Board has an easy to use tool to help identify weeds.
• Manually remove and prevent unwanted plants: while removing some plants is tricky, there are several strategies that may be used independently or in combination to combat weeds or invasives. After removing unwanted vegetation, plant native species in their place to help prevent regrowth.
• Use a natural “herbicide”: alternative options exist. Corn gluten, boiling water, or diluted rbbing alcohol are effective weed killers for use in yards and other green spaces.

Though insecticides are predominately used in the agricultural industry, the effects also impact urban environments. With numerous farmland bird populations declining, the concern with the overuse of insecticides applies to a wide range of native bird species.

Neonicotinoids, or neonics for short, are a category of insecticide that have been found to directly impact bird species. For migrating birds, opportunities to feed are crucial during their stop-overs. When a bird consumes fruit or seed from an area treated with neonics, the bird may experience adverse effects such as weight loss, which can weaken the bird and delay the rate at which they migrate, especially in songbirds.

When insecticides are used on a residential scale, such as on the exterior of a home, dead insects may litter the area near the application site. Birds that find insects dead from insecticides such as wasp spray, ingest them without knowing the toxicity of the chemicals responsible for the insect’s death. Additionally, spraying insecticide and ridding a yard of insect species including bees and other pollinators removes the foundation of food webs for birds and wildlife.

Insecticide-free solutions

• Try a natural insect repellant: using soap spray or diatomaceous earth for the exterior of homes, and neem oil for gardens and yards can provide safer alternatives to chemical-based insecticides.
• Reconsider your relationship with bugs: remember how important bees and other pollinators are to food webs. 96% of terrestrial birds feed insects to their young. Spraying for bugs in a yard can wipe out food resources for feathered friends. No bugs means no baby birds.
• Be mindful of how your food is grown: if you are able to select your own food to purchase, consider buying certified organic produce, which is required to be grown on land free from insecticides for at least three years. For tips on growing your own food, visit Seattle Audubon’s page Habitat at Home.