Hematologic reference intervals for wild Black vultures (Coragyps atratus).

BACKGROUND: The Black vulture (Coragyps atratus) is the most common species of vulture and is widespread in all America. The species feeds on rotting carcasses, and large groups are frequently seen in urban areas, concentrating especially on rubbish dumps. Although C atratus is a very common species in some areas, little is known about its health in the wild.

OBJECTIVES: The aim of this study was to determine hematologic RIs of wild adult Black vultures.

METHODS: Blood samples were obtained from 70 wild Black vultures captured in São Paulo, Brazil. Hematologic values were determined using conventional techniques applicable to birds. Reference intervals were determined using an Excel program with Reference Value Adviser (version 2.0).

RESULTS: After statistical analysis, the following RIs were determined: HGB 8.5-12.5 g/dL, PCV 42.3-54.5%, MCV 203.2-402.6 fL, MCHC 17.4-26.2 g/dL, total solids 2.4-4.8 g/dL, RBC count 1.16-2.48 × 106 /μL, WBC count 5.93-27.14 × 103 /μL, heterophils 3.40-21.58 × 103 /μL, lymphocytes 0.19-5.16 × 103 /μL, eosinophils 0.0-3.07 × 103 /μL, monocytes 0.0-1.49 × 103 /μL, basophils 0.0-0.25 × 103 /μL, and heterophil:lymphocyte ratio 1.3-36.9. Thrombocyte mean was 14.14 × 103 /μL.

CONCLUSIONS: Baseline hematologic data obtained in this study provide RIs that will be useful given that few studies have been carried out on the health of New World vultures.