Bovine tuberculosis in a possum from the Orongorongo Valley, Wellington

Abstract

The first confirmed case of a tubercular possum in the Orongorongo Valley forest is reported from a population intensively studied for 20 years. The victim was a five-year-old male recaptured 20 times over 3½ years. Its annual home range was about 1.8 hectares but this dropped to 0.4 ha during its last year of life. Its range overlapped with at least 15 others. The animal appeared normal and healthy in July 1985 but died of advanced, generalised bovine tuberculosis 12 weeks later. The nearest confirmed cases of tubercular possums were reported 1.3 km away in 1976 and 4 km away in 1979. The Orongorongo possum was unlikely to have contacted any cattle for over three years. The infection was probably transmitted from the Wainuiomata Valley by possums or pigs. The Orongorongo River was no barrier to the spread of the infection. Although most of the neighbouring possums were trapped and examined several times over the following year, no tubercular animals were detected.