Refuge use affects daily activity patterns in female Xenopus laevis

The African clawed frog (Xenopus laevis) is widely used for scientific research, but its ecology and behavior are poorly understood. In two experiments, the 24 h activity patterns of female X laevis were monitored. In the first, activity was determined both in the presence and absence of a refuge. In the second, a refuge was available throughout and activity was determined both in the presence and absence of another female. X. laevis were most active at night, and spent approximately half their time immobile on the floor of tanks during the day. They used refuges both in the day and night, but more so in the day. The presence of a refuge further reduced activity during the day. When a conspecific was present, X. laevis were less active, particularly during the day. This was related to an increase in individual refuge use, compared to when females were alone. There was no evidence of aggression, and females sometimes shared the refuge, providing no evidence of resource defense. These data highlight the nocturnal and communal nature of the species, and have implications for animal welfare. Environmental enrichment, for example in the form of refuges, is not standard for X. laevis, but they clearly chose to use it when available, and its presence modulated activity patterns. Wild X.laevis typically hide during the day, and providing a refuge allows them to do this in captivity. Refuges should therefore be provided where possible, and may ultimately provide a way to reduce overall animal use, if individuals maintained in this way in are healthier. (C) 2013 Elsevier B.V. All rights reserved.