Dead birds are often a sign that West Nile virus is circulating in a neighborhood. That’s why we ask you to report dead birds to www.westnile.ca.gov or (in the summer only) by calling the state West Nile virus hotline at 877-WNV-BIRD.
Some years, however, a large number of dead birds may have died from another disease: Salmonellosis.
Pine siskins are a small finch species commonly seen at birdfeeders. They’re more likely than other birds to get sick with Salmonellosis, and may die from this infection in large numbers. You can learn more about previous outbreaks of Salmonellosis in pine siskins from California Department of Fish and Wildlife's posts about the 2016 outbreak and 2020-2021 outbreak.
If you’re seeing multiple dead birds of the same species on your property, you can still turn them in for West Nile virus testing. However, we also recommend that you consider taking down your bird feeders for a while to avoid drawing more birds to the area. This will prevent the spread of disease between birds. You may also want to sanitize your bird feeders to remove any bacteria that may have been deposited in the birds’ droppings.
And finally, it’s important to remember that Salmonellosis in birds is caused by the same bacteria that can cause ‘food poisoning’ in humans, so remember to pick up dead birds with gloves or an inverted plastic bag, and always wash your hands after.