NEW ORLEANS (Reuters) - As if the deaths of 5,000 birds in Arkansas were not strange enough, Louisiana wildlife experts on Tuesday are investigating the deaths of 500 birds along a stretch of highway in Pointe Coupee Parish.

The Louisiana birds included some red-winged blackbirds, the same type discovered dead in Arkansas.

The mix of blackbirds and starlings were discovered on Monday between New Roads and Morganza, Louisiana, according to Bo Boehringer, press secretary for the Louisiana Department of Wildlife and Fisheries. That area includes the False River Regional Airport.

Boehringer said the birds were sent to labs in Georgia and Wisconsin to find out how they died, tests which could take a week.

“Our staff veterinarian is not ready to speculate at this time,” said Boehringer, regarding the cause of death.

The Louisiana report comes days after some 5,000 birds, mostly red-winged blackbirds, fell from the sky in Beebe, Arkansas on New Year’s Eve. Tests by Arkansas veterinary officials concluded Monday they died after massive trauma.

One theory is that birds were spooked by New Year’s fireworks and flew into buildings or other objects. Another theory is that severe weather caused the deaths.

“We’re leaning more toward a stress event,” said Arkansas Game and Fish Commission spokesman Keith Stephens, noting that severe weather had already left the area.

The Arkansas commission also is trying to determine what caused the deaths of up to 100,000 fish over a 20-mile stretch of the Arkansas River near a dam in Ozark, 125 miles west of Beebe. The fish were discovered December 30.

Stephens said disease may be the culprit, since almost all the fish were one species -- bottom-feeding drum.

Stephens said the Arkansas events do not appear related.