Playing music to captive chimpanzees has no positive effect on their welfare, researchers have concluded.
Previous research conducted with chimpanzees living in laboratories has suggested that playing music has positive effects on the animals' welfare, however, other research with zoo-housed primates has yielded mixed results.
Many zoos continue to broadcast music to their primates either as a form of enrichment or for the enjoyment of caregivers.
Research conducted by Dr Emma K Wallace, from the University of York's Department of Psychology, investigated how classical and pop/rock music affected the behaviour of the chimpanzees at RZSS Edinburgh Zoo to establish if it impacted positively or negatively on their welfare.
Further research involved a 'chimpanzee jukebox' , which allowed the chimpanzees at RZSS Edinburgh Zoo and the National Centre for Chimpanzee Care, Texas, the option to choose whether they wanted to listen to classical music, pop/rock music or silence.
Some of the music that the chimpanzees were able to select included work by Mozart, Beethoven, Adele and Justin Bieber.
The combined results of these studies show that neither classical nor pop/rock music has a positive effect on the welfare of these chimpanzees. They also did not show any consistent or persistent preferences for either type of music or silence.
Dr Wallace said: "These results suggest that music is not something that is relevant to captive chimpanzees and are supported by recent work with zoo-housed orangutans that were unable to distinguish music from digitally scrambled noise.
"However, whilst music does not appear to have a positive effect on captive chimpanzee welfare, it equally did not have any negative effects.
"As such it should not be considered a successful form of enrichment for these animals but, providing that the animals have the option to avoid it, music can still be played for animal caregivers."
"These results also highlight the possibility that music appreciation is something that is a uniquely human trait."The welfare of captive animals, especially those living in zoos, is of the utmost importance to those who care for them.
Providing animals with enrichment, such as toys, puzzle-feeders or unfamiliar smells, is a commonly used method of presenting the animals with mental challenges or novel forms of stimulation.
The research is published in PLOS ONE.