Other superstitions say that it has to be a white bird to be the messenger of death. It is also said to be lucky if a bird's droppings land on your car. I think it means that you park too close to pigeons.

The question appears to reference a superstition about what happens when a bird perches on or flies over a house after someone dies. However, this specific 'becoming a vampire' belief is not a widely documented mainstream superstition. While vampire folklore exists in various cultures (particularly Eastern European), this bird-related transformation is obscure. This may be a very regional or specific tradition, or possibly a misdocumented superstition.