RETROSPECTIVE STUDY OF MORTALITY IN CAPTIVE STRUTHIONIFORMES IN A FRENCH ZOO (1974-2015)

Abstract

The husbandry and medical records, and necropsy reports, of 1,002 captive Struthioniformes that died at the Réserve Africaine de Sigean (France) from 1974 to 2015 were examined. The goal of this study was to determine the most common causes of mortality in ostriches ( Struthio camelus), emus ( Dromaius novaehollandiae), and American rheas ( Rhea americana), in order to highlight common causes of mortality, as well as the influence of age, gender, and rearing methods on mortality. The most prevalent cause of mortality was pathology of digestive origin in the neonates of all three species, especially yolk-sac infections, which accounted for 41% of all deaths in this captive neonate population and was especially prevalent in hand-reared neonates. Other causes included musculoskeletal disorders in emus (particularly hand-reared) and rheas; trauma in neonate ostriches, mainly due to crushing by parents; leg deformities in emu chicks and juveniles; general sepsis in hand-reared ratite chicks due to a chlamydiosis outbreaks (1989-1990); trauma by conspecifics in subadult ostriches and emus; stress myopathy in subadult rheas, particularly after introduction to a new enclosure; evisceration inflicted by herbivorous enclosure mates on adult male ostriches; fatal peritonitis following salpingitis in adult female ostriches; and death associated with ocular disorder in adult male emus. Although this study was conducted at one institution, and its results reflect this zoo's management and zootechnical practices, its findings could well have implications for management practices involving other captive Struthioniforme populations.

Keywords: emu; ostrich; rhea.