Please e-mail h.m.buchanan-smith@stir.ac.uk for a personal copy of thsi article pubished in Applied Animal hence we argue that good enclosure design and husbandry is the most important factor in promoting positive interactions between individuals in mixed species groups. We conclude that long-term monitoring is important, and when combined with appropriate husbandry and enclosure upkeep, the welfare of individuals is enhanced in mixed species groups by the presence of other species.