Haematology of southern bent-winged bats (Miniopterus orianae bassanii) from the Naracoorte Caves National Park, South Australia

Haematology is an important tool for evaluating the health of both individuals and populations of animals, as it can provide evidence of subclinical disease. This is particularly important for endangered species as it provides a potential early warning system. The southern bent-winged bat (Miniopterus orianae bassanii) is a critically endangered bat whose population has declined over the past 50 years. As part of a larger investigation to determine if disease could be a contributing factor to the sub-species’ decline, complete blood counts were performed on southern bent-winged bats from the Naracoorte Caves National Park, South Australia, to determine their haematological characteristics. Erythrocyte and leucocyte morphologies were similar to other bat species. However, when compared with published results for Schreiber’s bent-winged bat (M. schreibersii), a closely related species, southern bent-winged bats had significantly fewer total white blood cells and a lower percentage of neutrophils, but a significantly greater percentage of lymphocytes, monocytes and eosinophils. Polychromophilus melanipherus, a haemosporidian parasite, was found in the blood of 28% of bats. This parasite was not associated with any pathological effects. This study highlights the importance of generating species-specific reference ranges as extrapolating from even closely related species can lead to errors in interpretation.