The onset of cold weather is when many homeowners begin feeding songbirds in windowsill and backyard feeders.
There’s less natural food available to the songbirds that over-winter here so the black-oil sunflower seeds, millet, thistle seed, wheat, corn and other small grains are a welcome addition to their diet.
An American Robin (Photo courtesy Audubon Bird Guide)
For many of us, feeding songbirds is a seasonal wildlife viewing tradition that begins during the year-end holidays and ends with the return of warm weather in late March and early April, as songbird migrations peak in preparation for spring nesting.
Two questions that avid bird watchers in Kentucky and the region are likely pondering are: 1) What caused the illness that killed songbirds this past spring and summer? 2) Are the die-offs going to continue in 2022?
“It’s not happening now,” said Kate Slankard, an avian biologist with the Kentucky Department of Fish and Wildlife Resources (KDFWR). “It peaked in the summer when birds were producing young, and was mainly a problem with recently-fledged birds.”
Wildlife officials in the region are at a loss to understand all the details of the mortality event, or to predict if it will reoccur. A definitive cause has yet to be identified. Laboratory testing and research is ongoing.
The research team of diagnostic laboratories investigating the cause of this die-off include the USGS National Wildlife Health Center, the University of Georgia Southeastern Cooperative Wildlife Disease Study, the University of Pennsylvania Wildlife Futures Program and the Indiana Animal Disease Diagnostic Laboratory.
An ill Blue Jay (Phot by Ginger Rood, courtesy of KDFWR)
KDFWR sent at least 40 samples for lab testing to the Southeastern Cooperative Wildlife Disease Study at the University of Georgia.
Christine Casey, DVM, a wildlife veterinarian at KDFWR said there are likely multiple factors contributing to the mortality event. “The problem is complex and labs are working on understanding the possible role of bacteria and toxicology in the affected birds,” said Casey. “The process to determine primary versus secondary causes for the problem are important and can lengthen the diagnostic process time.”
The good news is no issues with human health, domestic livestock or poultry have been reported.
Beginning in late May, wildlife agencies in nine states and Washington, D.C. started receiving reports of sick and dying birds, with birds exhibiting eye swelling and crusty discharge, as well as neurological issues.
“Some of the birds were trembling, not flying when approached, and appeared to be having seizures,” said Slankard.
The states where the bird illness were reported are east-central and coastal states, including Kentucky, and four bordering states — Ohio, Indiana, Virginia and West Virginia.
The majority of affected birds were juvenile common grackles, blue jays, starlings and robins.
“We assume that it affected other bird species, but that could not be confirmed through testing,” said Slankard.
On July 2, KDFWR reported that between June 17 and July 2 they received more than 1,400 reports of sick or dying birds, with about 250 found to be related to the unexplained illness.
In July they expanded the list of counties where they encouraged the public to stop feeding birds as a precaution since birds congregating at bird feeders can transmit diseases to one another.
The mystery illness peaked in spring when birds where reproducing (Photo from Flickr Commons)
The list included six counties with Bullitt, Campbell and Madison counties joining Boone, Jefferson and Kenton counties. A majority of the reports of sick or dying birds were coming from these counties.
By August 19, KDFWR had received 2,300 reports on its online reporting system, but the number of daily reports coming in began to decline in late June.
Biologists reviewed all reports carefully and found that many of the reported bird deaths were due to normal causes of mortality. Some reports contained limited information and were inconclusive.
Based on its assessment KDFWR rescinded its recommendation for residents in the six counties to stop feeding birds.
But biologists continue to strongly encouraged everyone feeding birds to clean bird feeders on a regular basis and to be on the lookout for any signs of disease in visiting birds.
“Keeping feeders clean is really important,” said Slankard. “There are lots of germs circulating out there.”
Clean feeders with a 10 percent bleach solution made from one-part bleach mixed with nine parts water.
A clean 5-gallon bucket is ideal for this chore. Submerge the feeder in the solution for about an hour, then rinse the feeder with clean water and allow to air dry.
If the mystery illness resurfaces, it is likely to happen next spring. To report a sick or dying songbird, visit their online reporting system at www.research.net.
