Risk Factors Associated with Developmental Limb Abnormalities in Captive Whooping Cranes

This retrospective survey identifies potential risk factors for developmental limb abnormalities in whooping crane (Grus americana) chicks reared at the International Crane Foundation between 1990 and 2006. We summarized a series of biologicallyrelevant preand post-hatch variables from this population using in-house aviculture and veterinary records, and then compared them between chicks with and without developmental carpal, toe and leg deformities. Chi-square analysis revealed associations between 1) rearing style and each type of deformity, 2) egg source and carpal and toe deformities, and 3) the pre-existence of a toe deformity and carpal and leg deformities. Multivariate analyses using logistic regression suggest that 1) increased risk of toe and leg deformities were highly associated with hand rearing, 2) lower relative weight change in week 1 increased the risk of toe deformities, 3) higher relative weight change in week 2 increased the risk of leg deformities, 4) female chicks and chicks from third clutch eggs were at increased risk of leg deformities, and 5) increased risk of carpal deformities was observed in chicks from eggs collected at Wood Buffalo National Park and in chicks with pre-existing or concurrent toe deformities. This information can be used by both aviculture and veterinary staff when making decisions regarding placement, management, and veterinary care to minimize the likelihood and impact of developmental limb abnormalities in captive reared whooping crane chicks. ProcEEDINGS of thE North AmErIcAN crANE WorkShoP 10:119–124