This paper summarises recent findings on the causation of stereotypic behaviours and other abnormal repetitive behaviours (ARBs) in captive animals: primarily motivational frustration and/or brain dysfunction, with possible contributory roles also being played by habit-formation and 'coping' effects. We then review the extent to which ARBs occur in zoos and similar, estimating that at least 10 000 captive wild animals are affected worldwide. We argue for 'zero tolerance' of such ARBs, because stress and poor welfare raise ethical issues, while abnormal behavioural phenotypes and possibilities of impaired brain development challenge both the indirect (e.g. educational) and the direct, intrinsic conservation value of affected animals. We then consider five potential means by which ARBs may be tackled: genetic selection; pharmacological treatment; the reinforcement of alternative behaviours; punishment; and environmental enrichment. All except punishment have potentially useful roles to play, but enrichment is the preferred approach: it is most likely to tackle the problems underlying stereotypic behaviours, and thence to improve both welfare and behaviour with few unwanted side-effects. Nevertheless, in zoos, environmental enrichment to date has only had partial success, with no study managing to abolish ARBs in all its subjects-suggesting either that the enrichments currently being used are never quite optimal, or that by the time they are tackled, ARBs have become resistant to change. We suggest some ways in which the effectiveness of enrichments may be enhanced; propose that certain properties of ARBs may usefully help evaluate their likely 'treatability'; and emphasise that if improving welfare is more important than just reducing ARB, then additional measures are needed in order to first, reliably identify those individuals most at risk from poor welfare, and then, to fully evaluate the welfare impact of enrichments. This paper also emphasises, with examples, the enormous potential value of zoo-derived data for helping understand
The stereotypies of individually caged Asiatic black bears (Ursus thibetanus) and Malayan sun bears (Helarctos malayanus) were studied in detail. Stereotypies were performed by 27 of the 29 subjects, were primarily locomotory in form (e.g., pacing), and occupied on average 18% (standard error of the mean (SEM) ¼ 2.5) of daylight hours. Stereotypy levels during the night were almost negligible and were highly correlated with daytime levels. Total stereotypies peaked prior to food arrival, although oral stereotypies were most frequent after feeding. In general, stereotypies were performed in locations from which food arrival could be viewed, although Asiatic black bears were equally likely to exhibit stereotypy near a neighboring bear. Across individuals, stereotypy frequency was inversely correlated with inactivity and increased with age. Older bears also showed less normal activity and a reduced diversity of normal behavior. Stereotypy levels were unrelated to levels of ''compulsive'' behavior (e.g., hair plucking) or repetitive self-sucking-a potential deprivation stereotypy. More frequent stereotypies were performed more invariantly (i.e., were more predictable from one repetition to the next) and in more diverse contexts, namely 1) outside the prefeeding period, and 2) during the night. Contrary to observations reported elsewhere, higher frequencies of stereotypy were not associated with reduced behavioral diversity, or with a more elaborate repertoire of stereotypy forms and sequences. Although the two species did not differ in overall frequency, the stereotypies of sun bears appeared to be more food-motivated than those of Asiatic black bears: the sun bears displayed a higher frequency and diversity of oral stereotypies, and higher levels of pre-feeding stereotypy, and performed significantly more of their total stereotypies in locations from which they could view food arrival. This study demonstrates how analyzing stereotypies in detail can help identify the motivations that underlie these behaviors, and potentially reveal their degree of establishment-both of which are important factors in stereotypy treatment.
Stereotypies are common in captive animals; yet, their underlying mechanisms are poorly understood. One hypothesis [Garner, J.P., 1999. The aetiology of stereotypy in caged animals. Ph.D. Thesis. University of Oxford, UK] proposes them to be symptoms of altered behavioural organisation (behavioural disinhibition) mediated by striatal dysfunction, and thus, fundamentally analogous to the repetitive behaviours associated with human pathologies such as schizophrenia and autism, or induced in animals by stimulant drugs and striatal lesions. Consistent with this, we previously showed stereotypy frequency to be positively correlated with inappropriate responding during the extinction phase of learning, a measure of 'perseveration' consistent with striatal dysfunction, in caged bears [Vickery, S.S., Mason, G.J., 2003. Behavioral persistence in captive bears: implications for reintroduction. Ursus 14,[35][36][37][38][39][40][41][42][43]. Here, adding new data, we strengthen this finding and look for further evidence of striatal involvement. Twenty-one bears of two species (Asiatic black bears (Ursus thibetanus) and Malayan sun bears (Helarctos malayanus)) were taught a simple food rewarded spatial discrimination task. Home cage stereotypy levels ranged between 1 and 45% of all observations (S.E. = 2.75), and high and low stereotypy bears did not differ in the ease with which they learnt the task. However, when responses were no longer rewarded (i.e. food rewards were withheld), as predicted, the most stereotypic animals took the longest to extinguish responding. Contrary to some previous studies, however, further evidence of striatal involvement was limited: behavioural switching rates were not related to stereotypy frequency or to perseveration, and levels of normal activity were only weakly related to perseveration (a trend), leaving the mechanism underlying the relationship between stereotypy and perseveration in these animals unclear. Alter- native non-striatal explanations include natural individual variation in habit-formation, general behavioural persistence or compulsiveness and these possibilities require further investigation. #
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.