Learmonth, M. J. 2019. Dilemmas for natural living concepts of zoo animal welfare. Animals 9(6), 318.

This ethical discourse specifically deals with dilemmas encountered within zoological institutions, namely for the concept of natural living, and a new term—wilding. It is agreed by some that zoos are not ethically wrong in principle, but there are currently some contradictions and ethical concerns for zoos in practice. Natural living is a complicated concept, facing multiple criticisms. Not all natural behaviours, nor natural environments, are to the benefit of animals in a captive setting, and practical application of the natural living concept has flaws. Expression of natural behaviours does not necessarily indicate positive well-being of an animal. Herein it is suggested that highly-motivated behaviours may be a better term to properly explain behaviours of more significance to captive animals. Wilding refers to extrapolation of the natural living concept to treating an animal as wild, residing in a wild habitat. This definition is intrinsically problematic, as quite literally by definition, captivity is not a wild nor natural environment. Treating a captive animal exactly the same as a wild counterpart is practically impossible for many species in a few ways. This article discusses complexities of natural living versus natural aesthetics as judged by humans, as well as the possibility of innate preference for naturalness within animals. Zoos nobly strive to keep wild animals as natural and undomesticated as possible. Here it is argued that unintended and unavoidable genetic and epigenetic drift favouring adaptations for life in a captive environment may still occur, despite our best efforts to prevent this from occurring. This article further discusses the blurred lines between natural and unnatural behaviours, and the overlaps with more important highly-motivated behaviours, which may be better predictors of positive affective states in captive animals, and thus, better predictors of positive well-being and welfare. Finally, as we are now in the Anthropocene era, it is suggested that human-animal interactions could actually be considered natural in a way, and notwithstanding, be very important to animals that initiate these interactions, especially for "a life worth living".