By Catelyn Fitzgerald ’23
Environmental Editor
Photo courtesy of pxfuel.com
Scientists are perplexed by an unidentified illness infecting birds in multiple states across the country. Wildlife authorities in Washington D.C., Maryland, Virginia, West Virginia and Kentucky began receiving reports of diseased birds in late May. Since the initial reports, birds with similar symptoms have also been spotted in Delaware, Florida, Indiana, Ohio, Pennsylvania and Tennessee. The illness appears to primarily affect birds’ eyes, with symptoms including “closed, weeping or crusted eyes” and eye lesions, according to the Audubon Maryland-D.C. Neurological symptoms are another aspect of the disease, causing infected birds to appear lethargic and swing their head from side to side.
While experts race to identify the elusive illness, authorities in the affected states are asking residents to take down bird feeders and bird baths to prevent the spread of disease.
Multiple bird species have been infected with the disease, some of whom, such as the house finch and the northern cardinal, are frequent visitors to these congregate spaces. Bird baths and feeders tend to bring different species together that might not interact in the wild and thereby increase the frequency of interactions between individuals, facilitating the spread of illness. Residents in the affected states have also been advised by the National Wildlife Health Center to clean feeders with a 10 percent bleach solution after taking them down.
The indiscriminate nature of the disease makes it more difficult to identify, as it is not specific to one geographic area or species. As of July, scientists have only been able to rule out a handful of diseases that have affected bird populations in the past, including avian influenza and West Nile virus.
While it is not certain to what extent backyard feeders play a role in the spread of the illness, they have been known to contribute to past avian disease epidemics. House Finch eye disease, for example, was first observed in birds visiting backyard feeders in Maryland and Virginia in 1994. Another feeder-associated disease, Trichomoniasis, killed up to 100,000 mourning doves in an outbreak from 1950 through 1951. Neither of these diseases have been effectively eradicated, with gatherings at feeders and bird baths allowing them to continue to spread.
Feeding birds is a fun and educational activity that, when done correctly, can make for healthy birds and great entertainment. In a survey of the MHN environmental section’s Instagram following, 49 percent of respondents reported they or their family feed birds in their backyard. Given the popularity of backyard bird feeding, it is important that feeders are properly cared for to prevent the spread of disease. Feeders should keep seed dry, as moisture can facilitate the growth of harmful mold in bird seed. If a feeder is not properly ventilated or if the bird feed is highly exposed to the elements, the feed should be replaced weekly. To prevent many different bird species from congregating at the same feeders where they might pass on an illness, households should put up more than one feeder across multiple locations and include different types of seed in each. Seed hulls discarded by birds can collect moisture and grow mold as they sit on the ground, so they should be removed to prevent ground-feeding birds — like the dark-eyed junco — from becoming sick.
Feeding birds is as much of a joy as it is a responsibility. Any form of wildlife feeding diverging from an animal’s natural eating habits poses risks such as spreading disease. Simple actions like taking down a bird feeder or reporting a sick bird can help halt the current disease outbreak, and if enough households follow wildlife authorities’ recommendations, it could bring the disease to a prompt end.