After a lion made a kill, birds will sometimes arrive to pick at the leftover carcass. which are the predators: the birds, the lion, or both? why?

Both depending on what type of bird it is The lion is obliviously a predator but the bird (depending what type it is ) makes it some what of prey to And the bird is also a predator cause ya it eats meat for sure so that tells you automatically this little or big bird can obviously kill something but it can also be a prey to the lion if the male/female grabs it in time so they are both predators/prey .  

is this a psat question, if so do not cheat try your best.