The nocturnal activity of a commonly housed rodent: How African pygmy dormice (Graphiurus murinus) respond to an enriched environment

Exotic rodents are becoming increasingly popular in industry; however, there is limited empirical evidence to guide husbandry practices. African pygmy dormice (Graphiurus murinus) are typical in this respect. This research aimed to determine the effect of environmental enrichment on the behavior (including stereotypical scratching at the glass walls of the enclosure) and space use of a group of eight African pygmy dormice at Sparsholt College Hampshire, UK. An apple-wood climbing grid and three raised (at various heights above the substrate) woven-wicker nest boxes were provided. Instantaneous scan sampling was used to record 150 hours of nocturnal behavior (19:00–07:00 daily) over five experimental phases (phase 1 baseline; phase 2 climbing grid provided; phase 3 lower nest box provided; phase 4 middle nest box provided; phase 5 higher nest box provided). Space use was determined using the modified Spread of Participation Index. Nest box use was recorded continually. The provision of the climbing grid significantly increased the groups' time spent eating, digging, gnawing, and climbing and significantly decreased stereotypic scratching at glass. It also significantly changed the use of all enclosure zones, with mice utilizing the highest zones as soon as they were accessible. The addition of raised nesting opportunity saw the highest zones of the enclosure become those preferentially used. It also totally diminished stereotypic scratching at glass. The highest nest box was preferentially used and use of terrestrial nest boxes (those placed directly on top of the substrate) reduced significantly when raised alternatives were provided. This study suggests those working with African pygmy dormice should provide an enriched enclosure via “arboreal” opportunity to increase active behaviors and reduce stereotypy.