Cooper, A., Spice, R. 2011. The use of mirrors as a form of environmental enrichment for the common marmoset (Callithrix jacchus). Animal Technology and Welfare 10(2), 79-84.

Primates have a fascination with mirrors. There is much literature available although no previous studies have been carried out to determine the benefits of mirrors for the Common Marmoset (Callithrix jacchus). Initially a six week study was conducted to assess whether mirrors provide visual stimulation for the marmoset and to examine any sex related differences in behaviour. A small follow up study was carried out after one year to determine if the marmosets habituated to the presence of the mirror. During the research period the mirror was used in a number of ways, including looking into and touching. The mirror was manipulated by the marmosets to enable them to see areas of the room which are not usually visible and proved to be a good form of enrichment for singly housed marmosets. One year after the mirrors were introduced the marmosets continued to use the enrichment item to the same magnitude and frequency as when first given. In addition, no significant difference was found between the results for the male and female subjects. This study suggests that mirrors can be used as an effective form of enrichment for the laboratory marmoset.