21. In African vervet monkeys, related females often form groups and gang up on males. 22. Vervet monkeys of East Africa were the first species documented to have distinct aural descriptions of predators.23. The green vervet monkeys in the rain forests up in the hills are more of a problem. 24. The vervet and malbrouck have often been considered conspecific, or as subspecies of the widespread grivet. 25. Hybridization between them is possible, and may present a threat to the vulnerable Bale Mountains vervet . 26. Common warthogs have also been observed allowing banded mongooses and vervet monkeys to groom them to remove ticks. 27. Their fur is grey green on top and whitish on their underside, much like the vervet monkeys. 28. Campbell's mona monkeys also generate alarm calls, but in a different way than vervet monkeys. 29. Research done on vervet monkeys showed that male and female monkeys gravitated towards sex-typical preferred toys. 30. In the field, researchers play tape recordings of vervet monkey cries to see how these affect real monkeys.
