A chacma baboon.
Célérier et al. (2010) uses mice to assess the relatedness of chacma baboons (Papio ursinus) through olfactory cues. But, why mice you asked?
Human noses are often quite weak compared with the rest of the animal kingdom, making it hard for us to find out if baboons can be told apart by smell. Researchers therefore decided to draft much better noses — those of mice. The researchers swabbed the armpits and groins of wild chacma baboons (Papio ursinus) from two different troops of the primates in Namibia. They next tested 24 adult male Swiss mice to scents from 14 adult female baboons. They chose female baboons partly because "some male mice were peeing on male baboon odors as if they were in competition," said researcher Aurélie Célérier, a behavioral biologist at the CNRS and the University of Montpellier II, France.
Their research shows that mice can detect odor differences between individuals of the same sex and age class in another mammal species, and that the mice can perceive a higher similarity between baboons that are related than baboons that are unrelated. These results show that olfactory cues may play a role assessing the degree of relatedness in among individual baboons. Detective mice assess relatedness in baboons using olfactory cues by Célérier et al. (2010) was published on The Journal of Experimental Biology. Also read Detective Mice Help Scientists Study Baboons by Charles Q. Choi on LiveScience.