The message
from "Dwayne" contains these words:

If the birds eat them, they aren't poisonous, unless you see a lot of dead
birds.

That's wrong advice. Birds and humans have very different digestive
systems so what is poisonous to one species may be harmless to the
other.

The commonest examples in Britain are yew berries and fruits of some
members of the nighshade family; birds eat both with no ill effects, but
they are poisonous to humans. Other examples are birds that can safely
feed on carrion (raw rotting meat) and the faeces of other species.
Humans can't.

Janet