How abnormal is the behaviour of captive, zoo-living chimpanzees?
BACKGROUND: Many captive chimpanzees (Pan troglodytes) show a variety of serious behavioural abnormalities, some of which have been considered as possible signs of compromised mental health. The provision of environmental enrichments aimed at reducing the performance of abnormal behaviours is increasingly the norm, with the housing of individuals in (semi-)natural social groups thought to be the most successful of these. Only a few quantitative studies of abnormal behaviour have been conducted, however, particularly for the captive population held in zoological collections. Consequently, a clear picture of the level of abnormal behaviour in zoo-living chimpanzees is lacking. METHODS: We present preliminary findings from a detailed observational study of the behaviour of 40 socially-housed zoo-living chimpanzees from six collections in the United States of America and the United Kingdom. We determined the prevalence, diversity, frequency, and duration of abnormal behaviour from 1200 hours of continuous behavioural data collected by focal animal sampling. RESULTS, CONCLUSION AND SIGNIFICANCE: Our overall finding was that abnormal behaviour was present in all sampled individuals across six independent groups of zoo-living chimpanzees, despite the differences between these groups in size, composition, housing, etc. We found substantial variation between individuals in the frequency and duration of abnormal behaviour, but all individuals engaged in at least some abnormal behaviour and variation across individuals could not be explained by sex, age, rearing history or background (defined as prior housing conditions). Our data support a conclusion that, while most behaviour of zoo-living chimpanzees is ‘normal’ in that it is typical of their wild counterparts, abnormal behaviour is endemic in this population despite enrichment efforts. We suggest there is an urgent need to understand how the chimpanzee mind copes with captivity, an issue with both scientific and welfare implications. The study is from School of Anthropology and Conservation, University of Kent, Canterbury, United Kingdom.
Birkett LP, Newton-Fisher NE. PLoS One 2011; 6(6):e20101. Epub 2011 Jun 16.
Disease prevalence in geriatric horses in the United Kingdom: veterinary clinical assessment of 200 cases
Reasons for performing study: Geriatric horses (aged ≥15 years) represent a substantial proportion of the equine population, yet few studies have investigated the prevalence of diseases within this population in the UK. Objectives: To describe the findings of veterinary clinical examination of 200 geriatric horses and ponies in north west England and north Wales, and to assess the effect of animal age and type (horse or pony) on the presence or absence of clinical signs and veterinary diagnosed health problems. Methods: From responses to a cross-sectional postal questionnaire survey of owners of geriatric horses (n = 918/1144), 200 horses were randomly selected to receive a veterinary clinical examination covering the major body systems. Results: Twenty-six percent of animals were overweight (body condition score, BCS, >3/5) and 4.5 per cent were underweight (BCS <2/5). Seventy-one percent had a dermatological abnormality and 22 per cent displayed hirsutism or abnormal moulting. Ophthalmic lesions frequently identified included vitreous degeneration (66.0 per cent), cataracts (58.5 per cent) and senile retinopathy (33.7 per cent). The prevalence of cardiac murmurs was 20 per cent. Whilst only 7.5 per cent of animals had a spontaneous cough during the examination, 18.5 per cent had some form of nasal discharge and 22 per cent had abnormalities on thoracic auscultation at rest. Following rebreathing, 13.6 per cent developed marked abnormalities consistent with lower airway disease. When assessed at walk, 18.6 per cent were lame on at least one limb, while 50.5 per cent were lame in trot. The majority of animals (83.5 per cent) had a reduction in range of motion in at least one joint. Eighty percent of animals had hoof abnormalities. Dental abnormalities were identified in 95.4 per cent of animals, with cheek teeth diastemata, excessive wear/cupped out teeth and focal overgrowths the most frequently identified conditions. Conclusions and potential relevance: This study has identified many prevalent clinical signs of disease in geriatric horses. Description of the most prevalent health problems and further identification of risk factors for these conditions will aid in targeted improvements in veterinary care, owner education and welfare. The report is from the Faculty of Health and Life Sciences, University of Liverpool, United Kingdom and Kessock Equine Veterinary Clinic, United Kingdom.
Ireland JL, Clegg PD, McGowan CM, et al. Equine Vet J 2011 Jun 13 [Epub ahead of print].