Authenticated by Dr David J. Chivers, University of Cambridge.
Arboreal: Living in trees.
Brachiation: In some Primates, a method of locomotion when the animal swings hand over hand from branch to branch.
Monogamy: Mating system in which a male and female mate exclusively with each other. The pair bond may last for one season or may be life-long.
Subspecies: A population usually restricted to a geographical area that differs from other populations of the same species, but not to the extent of being classified as a separate species.