Spreading the message that a dead bird is in the area helps safeguard other birds, alerting them to danger, and lowering their risk from whatever killed the original bird in the first place, the researchers say.
Other animals are known to take notice of their dead.
Giraffes and elephants, for example, have been recorded loitering around the body of a recently deceased close relative, raising the idea that animals have a mental concept of death, and may even mourn those that have passed.
I am reminded of the many Medieval poems about birds. See for, instance, the precis of this dissertation: http://digitool.library.mcgill.ca/R/?func=dbin-jump-full&object_id=77091&local_base=GEN01-MCG02 And this: http://archive.org/stream/medievalbookofbi00hughuoft/medievalbookofbi00hughuoft_djvu.txt
I am very fond of dream vision literature and especially that involving animals.