Chapter 18 - Health of Whooping Cranes in the Central Flyway

Abstract

The disease risks to Whooping Cranes and their recovery have almost entirely been described from ex situ or reintroduced populations. This chapter summarizes the first survey of physical and veterinary diagnostic findings directly from Whooping Cranes of the Central Flyway/Aransas Wood Buffalo Population. Thirty-eight adult cranes were captured at the Aransas National Wildlife Refuge in the winter (Dec–Feb) of 2009–2014. Rapid physical examinations revealed the cranes to be in generally good health. Hematology, serum biochemistry, serum protein electrophoresis, and blood trace element findings were compared to results from a current representative sample of captive Whooping Cranes, and the enteric bacterial flora of the wild cranes was compared to a previously published inventory from captive Whooping Cranes. The wild cranes were also screened for viruses of concern and blood parasites by microscopic and molecular methods. A separate, seasonal sampling scheme was used to identify endoparasites of wild Whooping Cranes. Important health characteristics of wild, as compared to captive, Whooping Cranes included: eosinophilia and hyperglobulinemia consistent with exposure to a greater array and density of parasites/antigens; serum biochemistry values that reflected their natural diet and stressful environmental conditions during the survey (limited fresh water); enteric microflora diversity; and previously poorly described prevalence of endo- and hemoparasites. West Nile virus, infectious bursal disease virus, and coccidian and hematozoan parasites were found, which may not result in severe morbidity or mortality under normal conditions, but may become pathogenic to Whooping Cranes in times of environmental change or host stress. Additional suitable habitat will be needed to help limit the transmission of and negative host effects from these agents among a growing population of wintering Whooping Cranes, especially in times of extreme environmental fluctuation.