Every elephant may have seen the same 2 monkeys. Also it is unclear whether the elephants are heading to the river or not. So we have definitvely:
The rabbit (no relation)
At least two monkeys
At least two parrots
For five minimum.
If each elephant saw two unique monkeys, we have:
The six elephants, who MAY have been heading for the river
Twelve monkeys (that'd be a good name for a movie)
For a maximum of 31 animals.