A different article makes the possible connection more clear:
> Some people commenting on Facebook and elsewhere speculate that people are spraying chemicals to deal with the current cicada emergence and that may be impacting the birds. There is absolutely no reason to spray cicadas, as the Animal Welfare League of Arlington said on Twitter:
https://www.birdwatchingdaily.com/news/birdwatching/terribly...
The tweet says:
> DON'T use insecticide on cicadas! Remember that many animals, including birds, bats, dogs, and cats, eat cicadas and can get very sick if they ingest insecticide. Help us keep local animals safe and well - the cicadas won't be here for that long, anyway!
https://twitter.com/AWLAArlington/status/1397332919639805955
Given that no pathogen has been found, this would seem to be a viable working hypothesis.
edit:
On the other hand, the birdwatchingdaily article also notes:
> In the last 10 days, people in the Washington, D.C., metro area have been reporting increasing numbers of sick, blind, injured, and dead birds. For the most part, they have been juvenile Common Grackles, European Starlings, and Blue Jays.
To be consistent with the hypothesis, these birds should be carnivorous.
edit:
> The common grackle forages on the ground, in shallow water, or in shrubs; it may steal food from other birds. It is omnivorous, eating insects, minnows, frogs, eggs, berries, seeds, grain, and even small birds and mice.
https://en.wikipedia.org/wiki/Common_grackle
> The common starling is largely insectivorous and feeds on both pest and other arthropods.
https://en.wikipedia.org/wiki/Common_starling
> The blue jay feeds mainly on seeds and nuts, such as acorns, which it may hide to eat later;[2] soft fruits; arthropods; and occasionally small vertebrates. It typically gleans food from trees, shrubs, and the ground, and sometimes hawks insects from the air. Blue jays can be very aggressive to other birds; they sometimes raid nests, and have decapitated other birds