The effects of husbandry on reproductive output and behaviour in captive saddle-billed storks (Ephippiorhynchus senegalensis)

Abstract

Zoos are required to understand specific husbandry requirements of animals in captivity, and there have been significant developments in husbandry research for captive breeding programmes. However, there is no ‘one size fits all’ and in some species, complications have led to low success and failure in breeding. Saddle-billed stork are notoriously difficult to breed in captivity, with low productivity reported in AZA and EAZA populations. Reproductive output, breeding behaviour and interspecific behaviour were measured in saddle-billed storks within European and American zoological institutions using a questionnaire. The effects of birth origin, enclosure provision, nesting provision and wing condition on reproductive output were analysed. The effect enclosure provision had on breeding behaviour and interspecific behaviour was also analysed. This research found three significant results related to the breeding status, reproductive success and breeding behaviour of saddle-billed storks. The breeding status varied significantly across institutions, with a significantly higher proportion of pairs scored as 'never bred successfully' compared to other categories. Additionally, storks of wild origin exhibited significantly greater success in producing clutches compared to those of captive origin. Furthermore, breeding behaviour rates were significantly higher in storks housed in smaller enclosures than those housed in larger enclosures. Sample size limitations prevented inferential analysis of the housing effect on interspecific behaviour. Despite the limited number of significant differences identified, the study provided insight into the potential influence of additional factors on the reproductive success and behaviour of saddle-billed storks. Specifically, husbandry practices such as flight restriction, housing conditions (MSE vs SSE), and nesting provision potentially influencing reproductive success, with housing conditions potentially affecting behaviour. However, the sample size was insufficient for testing fully. Small sample sizes of breeding birds have meant analysis was limited, however, this thesis can be used as a current review of husbandry practices across a range of zoos. This study has also highlighted areas of husbandry provision that it would be valuable to research further, such as enclosure furnishings that encourage nesting activity, nesting platform design, size, location and accessibility.