The ferruginous duck (Aythya nyroca) is a medium-sized chestnut-colored diving duck that inhabits wetlands of Europe and Asia. In recent years, this species has been declining throughout much of Europe—a decline that is attributed mainly to destruction of natural habitats, and to hunting and pollution. The ferruginous duck is listed as “near threatened” by the International Union for Conservation of Nature, and as a critically endangered nesting species in Israel. In 2009, a captive-breeding/reintroduction program was established in Israel, aiming to increase the species' population. The objective of this study was to collect data on normal hematology and plasma biochemistry analytes of ferruginous ducks in order to promote the species' conservation. Blood was collected from 49 birds, and 27 analytes were quantified. Compared to most other anseriformes studied, the ferruginous ducks in this study had lower white blood cell counts, which were dominated by heterophils rather than by lymphocytes.