COMPARATIVE HEMATOLOGY AND PLASMA BIOCHEMISTRY OF RED-TAILED HAWKS AND AMERICAN KESTRELS WINTERING IN CALIFORNIA

In December and January of the winters of 1990-91, 1991-92, and 1992-9 3, blood samples were collected from 52 Red-tailed Hawks (Buteo jamaic ensis) and 91 American Kestrels (Falco sparverius). Twenty-five blood parameters were measured, including white blood cell components, plasm a enzyme activities, and plasma chemistry concentrations. Interspecifi c comparisons were made to identify species specific differences perti nent to health assessment. American Kestrels had a higher incidence of hematozoa infection, higher alkaline phosphatase and acetylcholineste rase activities, and higher plasma cholesterol, blood urea nitrogen, u ric acid and sodium concentrations. Red-tailed Hawks had higher white blood cell concentration and eosinophil count estimates, aspartate ami notransferase and butrylcholinesterase activities, and a higher plasma albumin concentration.