Haematologic reference ranges of two remnant populations of the red-crowned parakeet (Cyanoramphus novaezelandiae ) in New Zealand

We present counts of white blood cells of wild and clinically normal red-crowned parakeets (Cyanoramphus novaezelandiae) from 2 island populations in New Zealand. Total white blood cell counts on slides prepared in the field and counts of relative proportion of basophils, eosinophils, heterophils, lymphocytes and monocytes were determined for 33 individuals caught on Little Barrier Island and 48 individuals caught on Raoul Island. Mean haematological parameters were: total white blood cells 6.85 cells x 109/L, lymphocytes 5.0 x109/L (74.0%), monocytes 3.5 x109/L (5.7%), eosinophils 4.6 x109/L (6.4%), basophils 1.9 x 109/L (3.1%), and heterophils 9.9 x109/L (14.7%). Raoul Island parakeets had significantly higher counts of white blood cells, lymphocytes, and heterophils than Little Barrier Island parakeets, possibly reflecting latitudinal differences. Males showed significantly higher counts of white blood cells and lymphocytes than females. White blood cell counts on slides prepared in the field represent an inexpensive and straightforward technique to determine variation in the levels of each cell type and to assess the physiological state of healthy and diseased individuals. This information is useful for veterinary clinicians, wildlife managers, and conservation biologists who increasingly require methods for health assessment, disease diagnosis, and screening for pathogenic microorganisms on species of conservation concern.