Seasonal effects on the haematology and blood chemistry of wild brushtail possums, Trichosurus vulpecula (Marsupialia : Phalangeridae) in New Zealand

Seasonal adjustments to red cell haematology that support altered metabolic requirements in Australian marsupials are either not expressed, or are min imal in brushtail possums introduced into New Zealand. Raised leucocyte dif ferentials in winter imply seasonal challenges to the immune system. A smal l increase in plasma glucose, fall in plasma protein, and generally high co ndition index are consistent with the relatively high quality of habitat en joyed by the marsupial immigrant.