Hematological and serum chemical constituents of blood were determined for 12 species, including 7 endangered species, of cranes, geese, raptors, and quail in captivity at the Patuxent Wildlife Research Center. Means, standard deviations, analysis of variance by species and sex, and a series of multiple comparisons of means were derived for each parameter investigated. Differences among some species means were observed in all blood parameters except gamma-glutamyl transpeptidase. Although sampled during the reproductively quiescent period, an influence of sex was noted in red blood cell count, hemoglobin, albumin, glucose, cholesterol, serum glutamic oxaloacetic transaminase, Ca, and P. Our data and values reported in literature indicate that most hematological parameters vary among species and, in some cases, according to methods used to determine them. Therefore, baseline data for captive and wild birds should be established by using standard methods, and should be made available to aid others for use in assessing physiological and pathological conditions of these species.