Hematologic and biochemical reference intervals of free-living Red-Tailed Amazon parrot (Amazona brasiliensis) nestlings on Rasa Island, Paraná, Brazil.

Background: The Red-Tailed Amazon parrot (Amazona brasiliensis) is an endangered species of the Psittaciformes. There is little information about hematologic and biochemical variables of this species.

Objectives: The purpose of this study was to determine hematologic and biochemical RIs for free-living A brasiliensis nestlings on Rasa Island, Paraná, Brazil, and to compare the results between sexes.

Methods: Thirty-seven parrots were taken from their nests and physically restrained for clinical examination and blood collection. The sex was diagnosed by PCR using the blood samples collected. Reference intervals were determined as recommended by the ASVCP guidelines in healthy nestlings. The difference between groups was analyzed using the Mann-Whitney test or Student's t-test.

Results: Sexing revealed 12 females and 25 males. The RIs for the measured variables were as follows: RBC 1.1-2.6 × 10 /μL, PCV 29.1-50.3%, HGB 7.2-12.9 g/dL, MCV 152-293 fL, MCHC 22.2-28.4 g/dL, WBC 4.9-28.5 × 10 /μL, 1.2-16 × 10 /μL, lymphocytes 2.4-18.7 × 10 /μL, monocytes 0.0-1.0 × 10 /μL, eosinophils 0.0-0.9 × 10 /μL, 0.0-1.3 × 10 /μL, heterophil:lymphocyte ratio 0.0-2.2, plasma total solids 2.1-3.7 g/dL, uric acid 0.5-2.0 mg/dL, glucose 184.9-284.3 mg/dL, AST 100.3-226.6 U/L, LDH 178.1-927.7 U/L, CK 149.8-1144.0 U/L, cholesterol 137.5-256.9 mg/dL, total protein 1.8-3.0 g/dL, calcium 7.0-8.6 mg/dL, and phosphorus 2.9-6.1 mg/dL. Increased concentrations of cholesterol (P < .05) were observed in females.

Discussion: This is the first study to establish hematologic and biochemical RIs for free-living A brasiliensis nestlings on Rasa Island. Hematologic and biochemical variables are important tools for evaluating the health status of free-living birds, and also support conservation planning for endangered species.