Blood Parameters in Natural Populations of Trichosurus Species (Marsupialia: Phalangeridae). I. Age, Sex and Seasonal Variation in T. Caninus and T. Vulpecula. Ii. Influence of Habitat and Population Strategies of T. Caninus and T. Vulpecula.

Abstract

Age, sex and seasonal related changes in body weight and blood parameters were determined for T caninus and T. vulpecula, whose distribution overlapped in part of the study area. In T. caninus age-related changes occurred in body weight, mean plasma glucose and protein concentrations and haematocrit. Seasonal changes occurred in plasma glucose and protein concentrations, haemoglobin concentration and red blood cell count. There were sexual dimorphisms in haematocrit, haemoglobin concentration and red blood cell count in both species; the mean values were greater in males. T. vulpecula also exhibited a sexual dimorphism in body weight (males > females). The only seasonal change in T. vulpecula was in haemoglobin concentration. Comparison of the species as adults showed that T. caninus had higher mean levels of body weight, haematocrit and haemoglobin concentration, while plasma lipid concentration and red blood cell counts were greater in T vulpecula. These species differences may be a reflection of the diets of the two species. In addition the measured parameters showed greater seasonal variation in T. caninus, a K-selected species, than in T. vulpecula, which is more r-selected.