Reintroduction medicine: whooping cranes in Wisconsin.

Abstract

This paper presents veterinary management strategies and diagnostic findings in the reintroduction of the endangered whooping crane (Grus americana). Between 2005 and 2010, 63 (27 male, 36 female) hatchling whooping cranes were assigned to a reintroduction project involving autumn release of costume-reared chicks in Wisconsin. Veterinary care included preventive measures and comprehensive pre-release evaluations to improve fitness and reduce translocation of potential disease agents to native habitats. A total of 44 clinically normal birds were released (70% of assigned individuals). Cases of morbidity were classified according to primary body system affected. Musculoskeletal disorders were described in 57 birds (90%); five birds were removed from the project prior to release (8%), all for abnormalities that prevented normal function. Fourteen birds died or were euthanized prior to release (22%); pre-release mortality was attributed to developmental abnormality, predation, trauma or infectious disease. Chronic respiratory aspergillosis, diagnosed in seven birds (11%), was the most common infectious disease of concern. Predation and trauma were primary causes of post-release mortality; no evidence of infectious disease of captive origin was detected in the study population by the end of 2010. The assessment of data accumulated by this project helped to outline successful health management strategies, as well as identify and mitigate ongoing risks to captive whooping cranes that impede reintroduction efforts and achieving management goals for species recovery.