Figure 3.

How the first two eigenface dimensions were together able to classify individuals of A. nigroviridis with 95.20% cross-validated accuracy (chance = 14.17%). Differently coloured symbols represent different individuals (n = 7). Repeat photographs of each individual are generally clustered together, enabling accurate classification. Eigenface 1 corresponds closely with skin colour and eigenface 2 relates to fur colour. Triangle symbols show males and circles show females. Thick symbol outlines show older adults and thin outlines show younger adults. Note that although we did not have sufficient sample size to run classification analyses on A. nirgroviridis age and sex identity, males and females and younger and older adults overlap in space, so that individuals cannot be easily separated into these categories on the basis of these two eigenface dimensions. (Online version in colour.)