Wildlife and Pesticides

Pesticides are substances used to kill or control pests. Pesticides are usually not entirely specific in their action, and can affect plants and animals they are not intended to harm. Generally speaking, insecticides are more toxic to wildlife than herbicides or fungicides.

Wildlife can be exposed to pesticides directly, by eating contaminated food or water, breathing pesticide spray, or absorbing pesticides through their skin. Predators such as hawks and owls can become poisoned by eating other animals that have been exposed to pesticides. Because many insecticides affect the nervous systems of wildlife, exposure to a particular insecticide can affect animals indirectly, by interfering with their ability to survive or reproduce. For example, wildlife may be unable to escape from predators or incubate a nest properly.

Herbicides can affect plants that are important to wildlife survival. Killing weeds along a fencerow removes seed producing plants important for many species, and destroys cover and travel corridors for wildlife. Young animals often depend on a diet of high protein insects to grow. Because these insects depend on plants to survive, killing the plants removes insects on which other wildlife depend.

Amphibians, fish, and aquatic insects are very susceptible to pesticide contamination of water. When these creatures are killed by runoff or drift of pesticides into water bodies, other animals such as ducklings, who depend on these creatures for survival, also suffer.

Before deciding whether or not to use a pesticide, ask yourself whether treatment is really necessary. Are there other techniques like cultivation or crop rotation that would control the pest without using pesticides? If you decide that pesticide use is necessary, follow the guidelines below to reduce the impact you will have on wildlife. Every pesticide user must accept the responsibility of reducing impacts of pesticide use on nontarget plants and animals.

  • Always use the least toxic and least persistent product that will do the job. Find out the toxicity of the product to the user by reading the label, and assume that the product is as toxic or more toxic to birds and other wildlife.
  • Read and follow the label instructions. Heed any special warnings on the label regarding wildlife.
  • If you have a choice, don't spray during the breeding season for wildlife on your land. Never spray near nests, dens or burrows.
  • Protect valuable wildlife areas by staying well away from field edges, woodlots, ditches, hedges, rockpiles, fencelines, and wetlands. Don't let pesticide sprays drift onto these habitats.
  • Don't puddle sprays during application or when cleaning equipment. Birds and other wildlife may be attracted to water to bathe or drink.
  • Avoid using the granular formulations of extremely toxic insecticides. Soil incorporation of these products is rarely adequate and birds can eat the granules by mistaking them for food or grit. If you must use granular insecticides, try to avoid spills that occur at the ends of rows, over rough areas, or when loading. Clean up or cover any spills with soil.
  • Inspect your fields carefully. Avoid the repeat use of any product that causes wildlife deaths. Our experience has shown that you are seeing only the "tip of the iceberg".
  • Use the lowest application rate recommended for a product.
  • Do not wash pesticide application equipment in any body of water, whether permanent or temporary in nature. If you draw water from ponds, streams or lakes, use an anti-siphon device to prevent backflow.
  • Avoid overlapping spray swaths and when possible, "spot spray" only those areas that need treatment.
  • Try to avoid pesticide drift by not spraying on windy days. Use buffer zones to reduce problems with non-target drift and runoff. Don't apply pesticides if there is potential for heavy rainfall soon after application.
  • Store, treat and dispose of pesticide containers properly. Your extension agent can provide you with information if you are unsure of how to treat pesticide containers.
  • Report any incident of wildlife mortality to the Department of Game and Inland Fisheries. Your observation and feedback are needed to reduce wildlife risk in the future.

Integrated pest management and sustainable agriculture can benefit wildlife by reducing pesticide use and increasing diversity. You can find out more about these techniques by contacting the Virginia Association of Biological Farmers, Virginia Cooperative Extension, or the Virginia Department of Agriculture and Consumer Services. For more information about the effects of pesticides on wildlife, contact the Virginia Department of Game and Inland Fisheries, P. O. Box 11104, Richmond, VA 23230, and request the free booklet "Pesticides and Wildlife: A guide to reducing impacts on animals and their habitat".


  • Fungicide - A pesticide that kills fungi.
  • Herbicide - A pesticide that kills plants or inhibits their growth.
  • Insecticide - A pesticide that kills insects.
  • Label - All printed material attached to or part of a pesticide container.
  • Non-target organism - Any animal or plant other than the intended target of a pesticide application.
  • Pesticide - Any substance used for controlling, preventing, destroying, or repelling any pest.
  • Toxic - Poisonous