Last spring songbirds began dying off in the Washington, D.C., Maryland and Virginia areas and the reports began spreading, leading the Pennsylvania Game Commission to issue an alert July 1 asking state residents to take down bird feeders and birdbaths to prevent avians from congregating.
It was thought the birds could be spreading the illness that caused crusty eyes, neurological symptoms and eventually death as they fed and bathed. The feeding ban was lifted by the commission on Aug. 13.
What killed the birds in spring and summer 2021? That has yet to be answered.
“Results have been inconclusive,” Martin J. Hackett, communications director for the School of Veterinary Medicine at the University of Pennsylvania, also known as Penn Vet, said in a February email. “I can tell you that a working group, composed of the Ohio State University Wildlife Futures Program staff and the University of New Hampshire, has been organized to collate and analyze collective pathogen sequencing results related to last summer’s songbird die-off event. The effort will result in a comprehensive publication of all findings.”
The Wildlife Futures Program is a joint venture of the Pennsylvania Game Commission and Penn Vet launched in 2019.
Earlier this month Hackett shared data obtained from the public Bird Mortality Reporting Form set up last summer.
“Confirmed cases were those visually inspected by our Wildlife Futures field staff,” Hackett said. “So in the case of Berks, our field staff did not make firsthand inspections. But the citizens of Berks County did a good job of furnishing photos or providing accurate descriptions that our field staff felt confident designating mortality as probable.”
John Donges, communications coordinator at Penn Vet provided additional regional data.
“For Chester County, 255 cases were reported out of the 3,242, accounting for 7.9% of the total,” Donges wrote. “For Montgomery County, 298 cases were reported accounting for 9.2%. All cases were deemed confirmed, visually inspected by our Wildlife Futures field staff.”
Others in the ornithological world are still perplexed.
“We aren’t sure of the root cause,” said Bracken Brown, a biologist-naturalist with Hawk Mountain Sanctuary in Albany Township. “I know there was a partnership between the U.S. Geological Survey and its National Wildlife Health Center to analyze specimens collected from all the states that were finding dead birds. And the best we got, the last I remember reading, was in the fall, where they had essentially gone through and tested the specimens to look at whether they were hosting some of the common expected diseases like West Nile Virus, salmonella, some of those broad-reaching vectors. And they canceled all of the known ones out.”
He said that was a bit alarming with such a large-scale rapid event.
“Theories got quite exciting,” Brown said. “They had it down to association with the Brood X cicada emergence and one of the theories was there was a fungus associated with the mycorrhizae in the soils that they were bringing up and then that was getting fed to the young. Again, that could have been responsible for some of the symptoms, not all of them.”
Mycorrhizae is a condition when fungus invades plant roots and the relationship is beneficial for both according to the University of Nevada Cooperative Extension.
“So we’re still in the dark as far as what the cause was,” Brown said. “But what’s interesting is that it impacted a wide diversity of bird species, all of which are common backyard birds. So that always raises the concern that this was a potential human byproduct.”
The species most affected were blue jays, American robins, grackles and European starlings.
“Whether it was an insecticide, a new insecticide getting sprayed out in the environment across the eastern seaboard that was having this impact or it could have been multiple things working together,” Brown said earlier this month. “It is worth noting that all of the affected species were common backyard birds.
“That is something to keep an eye out, especially if you have a bird feeder. That is a concentration point where all of the birds in your backyard are going to come for resources, share the same space and anything transmissible can be transmitted.”
He said Hawk Mountain Sanctuary did not have any birds affected at its visitor center feeders.
Brown suggests keeping all bird feeders, trays and decks clean as the warmer months arrive.
“Cleanliness is definitely something to keep an eye on,” Brown said. “I was surprised at how many homeowners led with, ‘Should I be cleaning my bird feeders?’ It’s a good idea to keep a clean feeding station whether you’re feeding humans or the wildlife. I always recommend that.”
He suggests using a diluted bleach solution to clean bird feeding areas, then rinsing it with plain water. The game commission recommended using a 10% bleach solution last year.
“A diluted bleach solution takes care of most of your potentially harmful bacteria,” Brown said. “Just rinse it off afterward.”
Brown did say to take down your feeders if you see any sick birds. He said house finches are prone to an eye conjunctivitis that can quickly spread.
“It’s easily transmittable, so they recommend that you take your feeders down so they disperse and aren’t going to spread that throughout the entire flock,” Brown explained.
Source: Berkshire mont
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