West Nile and Dead Birds

Key points

  • West Nile virus has been detected in variety of bird species.
  • Some infected birds, especially crows and jays, are known to get sick and die from the infection.
  • Reporting and testing of dead birds is one way to check for the presence of West Nile virus in the environment.
  • Some surveillance programs rely on citizens to report dead bird sightings to local authorities.
Image of a raven

How do birds get infected with West Nile virus?

West Nile virus is transmitted to birds through the bite of an infected mosquito. Mosquitoes become infected by biting infected birds. Some birds that are predators (such as hawks and owls) or scavengers (such as crows) may become infected after eating sick or dead birds that were already infected with West Nile virus. Some birds that eat infected mosquitoes may also become infected.

Do birds infected with West Nile virus die or become ill?

Although some infected birds, especially crows and jays, frequently die of infection, most birds survive. Since West Nile virus was discovered in the United States in 1999, the virus has been detected in over 300 species of dead birds.

Can I get West Nile virus directly from birds?

There is no evidence that a person can get infected from handling live or dead infected birds. However, you should avoid bare-handed contact when handling any dead animal. If you must pick up a dead bird, use gloves or an inverted plastic bag to place the bird in a garbage bag.

What should I do if I find a dead bird?

State and local agencies have different policies for collecting and testing birds, so check with your state health department or state wildlife agency for information about reporting dead birds in your area. Wildlife agencies routinely investigate sick or dead bird events if large numbers are impacted. This type of reporting could help with the early detection of illnesses like West Nile virus or avian influenza (bird flu), known to cause death in birds. If local authorities tell you to simply dispose of the bird, don’t handle it with your bare hands. Use gloves or an inverted plastic bag to place the bird in a garbage bag, which can then be disposed of in your regular trash.

Why did some states and local areas stop collecting dead birds to test for West Nile virus?

West Nile virus is found in all 48 contiguous states (not in Alaska or Hawaii) and the virus circulates in mosquitoes and birds every year. Because West Nile virus is well established, some states and local jurisdictions are no longer collecting dead birds for testing. Instead, they have chosen to shift staff and funding resources away from testing of dead birds to other areas of West Nile virus surveillance and control.