In dreams, dead birds can symbolize a loss of freedom. Various cultures view birds either as a way the soul is carried to heaven, or, in the case of vultures, ravens and crows, as a symbol of death.
Since childhood on, I have an attraction to dead pigeons or birds. Where this is coming from interest or enthusiasm, I can hardly put into words. But I am fascinated by this fall-symbolism. Whether religious activities or natural events, the background is always the same: The death turns his index finger from top to bottom. These pictures are from the internet, as I began some time ago to search for this topic.