Suggested answer for incorrect referencing
One way of avoiding repetitive referencing is to improve punctuation and use connectives. Here is a suggestion of how you could achieve this;
The largest group of Old World ground monkeys is the Family Cercopethidae, the baboons. Different species in this group eat a wide variety of food that can be found almost anywhere; the more kinds of food an animal can eat, the better chance it has of survival (Dennard, 1999). Baboons eat fruit, seeds, plants, insects and meat. They also dig underground for roots and bulbs and sometimes hunt small animals. The males are fast and powerful runners and have very large, sharp canine teeth; a group of males can chase down a small antelope (Dennard, 1999). Another reason there are so many species of baboon is that they can live in many different places (Dennard, 1999). For example, Hamadryas baboons live in near-desert areas of Ethiopia and Arabia, Gelada baboons live in the mountains of Ethiopia, in Tanzania olive baboons live in the rain forest and on the open savannahs while in South Africa, chacma baboons live near water and even eat water lilies (Dennard, 1999).
This has halved the number of times the reference is referred to. You may be able to reduce this even further. You do need to let the reader know that all the information does come from the one source, but you must also avoid endless repetition of the same reference. It is a difficult balance, but as you use more sources, it will cease to be a problem.