Several readers have asked about the bird mortalities that have been occurring since May in northern Virginia, the District of Columbia, Maryland, Ohio, Indiana, Kentucky and West Virginia.
Lynchburg Bird Club President Gene Sattler says he doesn’t know of any cases reported in central or southwest Virginia.
The most commonly afflicted birds are blue jays, common grackles and European starlings. The ailment also has been observed in robins, cardinals, Carolina wrens, gray catbirds, house sparrows and northern flickers.
Symptoms include crusty or puffy eyes causing blindness, signs of seizures and loss of balance.
Based on federal and state agency recommendations, the Lynchburg Bird Club suggests if you continue to feed birds, wash your feeders weekly with a 10% beach solution.
In an abundance of caution, you may want to take your feeders down for a while, with the assurance there is plenty of natural bird food around.
Some organizations, including the Southwest Virginia Wildlife Center of Roanoke and the West Virginia Department of Natural Resouces, are urging bird enthusiasts to take down their feeders, though that does not apply to nectar feeders for hummingbirds.
If you find a bird that has eyes that are crusty, puffy or have discharge or neurological problems including head tilt, rapid eye movements or lack of coordination, report it on the Virginia Department of Wildlife Resources Bird Mortality Form at: https://dwr.virginia.gov/wildlife/diseases/bird-mortality-reporting-form/
If you find birds that have died from a window or car strike or cat predation, there is no need to report those findings.
One theory emerging about the cause of these inexplicable deaths comes from Brian Evans, a bird ecologist with the Smithsonian Migratory Bird Center.
Evans realized that as trillions of cicadas emerged from their 17-year nap, birds that feasted on the insects died in large numbers.
While it’s not clear the cicadas were responsible for the bird deaths, the deaths largely overlapped with areas where Brood X (10) of the cicadas emerged. We are not near that brood.
Evans said there are no good estimates on how many hundreds or thousands of birds have died, but more than 600 birds suffering from the symptoms have been taken to wildlife rehab centers.
One theory is a fungus called massospora, which infects cicadas, may negatively impact birds as they gobble down the protein-rich insects.
Pesticides also are a potential cause. Evans said the cicadas have lived underneath us for 17 years and could have been accumulating toxins such as pesticides or heavy metals in the soil.
High concentrations of such toxins could be lethal as the birds switched their diets to cicadas.
Evans said it appears that as the cicadas die off, bird mortality is starting to go down. The cicadas emerge for about six weeks from May to early July.
The apparent reduction in bird mortality is cause for optimism because birds can take a once-every-17-year hit on their populations, Evans said.
On the other hand, cicadas may not be the culprit. No doubt biologists will continue working to clear up this mystery.
Shannon Brennan can be reached at firstname.lastname@example.org.