Cause of summer songbird deaths remains unknown

In early August, the Indiana Department of Natural Resources announced residents in 76 countries around the state could safely return their birdfeeders and baths to their yards. Earlier in the summer, DNR advised residents in all counties to remove them due to a mystery illness causing fatalities in the state’s songbird population. Since Experts and state officials did not know what the disease was or how it was spread, this was recommended as a precautionary measure.

Months after the initial announcement regarding songbird deaths, the DNR, ornithologists and wildlife researchers still don’t know the source of this illness. Residents of Allen, Hamilton, Hendricks, Johnson, Lake, Marion, Monroe, Porter and St. Joseph counties have all been instructed to keep feeders down until further notice.

Although the illness has still not been identified, Barny Dunning, professor of forestry and natural resources (FNR), said the DNR in Indiana and other states are forming a better picture of what species the disease targets and the geographic areas where it is active.

“I have heard updates, mostly from the DC area, that the number of affected birds has been steadily declining for weeks now,” Dunning added. “The illness also seems to have mainly impacted very young birds and, of course, the breeding season is winding down and there are few younger, more susceptible birds.”

While Brood X cicadas were largely ruled out as a cause of the illness, Dunning said researchers are revisiting that theory because the course of the sickness closely mirrors the lifecycle of Brood X.

“Reports suggest that if this was an infectious disease, cases wouldn’t be descending like this,” Dunning continued.

Labs, like Purdue’s Animal Disease Diagnostics Lab, will continue testing on birds and researchers are still working to identify the source of the illness.

The symptoms of this affliction include crusty eyes or discharge from the eyes and signs of neurological distress, such as tremors or stumbling. Reports of a sick or dead bird with these symptoms should be reported to the DNR.

“Tracking the location and rate of this illness is key to unlocking its source and that strategy relies heavily on residents reporting sick birds,” Dunning said.

Featured Stories

A landscape view of Pfendler Hall, one of the three buildings that houses faculty and staff from Purdue Forestry and Natural Resources.
FNR Honors Four Individuals for Department Service in 2025

The Purdue Department of Forestry and Natural Resources has honored four individuals for their...

Read More
the Szymanski and Siegmund labs stand together in front of photos and models of leaf epidermis on a screen between them.
Sticking together under stress: NSF grant brings plant biologists and engineers together to discover how tissues stay connected

Daniel Szymanski, professor of Purdue’s Departments of Botany and Plant Pathology and...

Read More
Ag Barometer
Farmer sentiment drifts lower as trade uncertainty hangs over agriculture

Farmer sentiment dipped slightly in December, with the Purdue University/CME Group Ag Economy...

Read More
Photos from the top 2025 stories for Purdue College of AG
What people clicked, watched and read in 2025

Explore the top content from 2025 for the Purdue College of Agriculture.

Read More
Wildlife alumna Lauren Wetterau kneels next to a red squirrel midden in the Greater Yellowstone ecosystem; a red squirrel sits on downed tree
Alumna Lauren Wetterau's Research Featured on Animal Planet Show

2023 wildlife alumna Lauren Wetterau is coming to a television screen or streaming service near...

Read More
Lenny Farlee shows teachers how to use a Biltmore stick at the Natural Resources Teachers Academy.
FNR Extension Set to Offer Four Editions of Forest Management for the Private Woodland Owner Course in Spring 2026

Do you want to learn more about trees, forests and how to better manage your woodlands for a...

Read More