Officials report that more dead birds have been found littering the streets in Sweden.

Wednesday dawned with the discovery that more than 50 jackdaws had fallen from the sky for, again, unknown reasons.

There have been plenty of reports of dead birds showing up in the news over the past few days, all following the report of 5,000 blackbirds inexplicably raining from the New Years sky in Beebe, Arkansas. Experts say the the increasing number of reports making headlines stems not from more cases of mass bird kills than usual, but rather from heightened public awareness of the events.

Robert ter Horst, a Swedish veterinarian, says that the deaths could have been caused by any number of factors, from fireworks, to food shortages, to the cold weather. Many experts claim that the recent bird deaths have been caused by stress from fireworks, although some aren’t so sure.

Five of the recently found birds are being tested in a Swedish lab to determine the exact cause of death.

The dead Arkansas birds and the Louisiana birds were said to contain massive clotting and internal bleeding, lending validity to the theory that the deaths were stress related.

According to Horst, the birds’ deaths could have even been caused by being run over by vehicles.