In fact giraffes rarely cluster together unless they happen to be attracted to the same tree, nervous over the presence of lions, or aggregated in the open.
(giraffes; cluster together; T:rarely) (they; happen; ) (they; to be attracted; to the same tree, nervous over the presence of lions, or aggregated in the open)
giraffes they they
cluster together happen to be attracted
T:rarely
to the same tree, nervous over the presence of lions, or aggregated in the open