Influence of capture method, habitat quality and individual traits on blood parameters of free-ranging lace monitors (Varanus varius)

OBJECTIVE The aims of this study were to determine baseline reference intervals for haematological and serum biochemical parameters in lace monitors, and to examine whether such values were influenced by capture method, expected differences in habitat food resource availability and a lizard's body size and body condition. METHODS Thirty-three wild Victorian lace monitors (Varanus varius) of unknown age and sex were captured by noose pole or aluminium box trap from Cape Conran in East Gippsland, Victoria, Australia. RESULTS No statistical differences between the two capture methods were noted for haematology. There was a significant difference in the serum glucose concentrations between the two methods of capture (higher concentration in box-trapped animals) because of a physiological response to capture stress. Habitat food quality did not appear to influence haematology or serum biochemistry. The packed cell volume (PCV) for the lace monitors was 0.29-0.43 L/L. Lymphocytes were identified as the most common leucocyte. The haemoprotozoan parasite, Haemogregarina varanicola, was found in all 33 blood samples. No correlation could be made between parasite burden and PCV, serum globulins or serum proteins, but animals in poor body condition were more likely to harbour large numbers of parasites. CONCLUSION The results of this study may be used as a basis for evaluating health in lace monitors.