Bird mass-death and the possible reasons for that 1) What are the shape and the size of the area, where the birds are found? This is the thing, what is the most important thing because if the dead birds are found all around, that is telling about poisoning. If the dead birds are found in the area, what looks like some route, that means that something, what is flying in that route causes the deaths. When we are thinking about the cases, that those dead birds are found mainly on the motorways, that could mean that something has been followed that road, and used it as the landmark for flying. If the area, where the birds are limited, that could mean that something like test plane has come low, and then rise back to higher altitudes, or maybe that thing has been decreased the speed. There are two possibilities, those tracks are made by some chemical or the birds have fallen because of the pressure wall, called a sonic boom. If the sonic boom has caused the mass deaths of ...