Early ecological research on rodents in New Zealand, 1946–1976: personal recollections

Ecological research into rodents in New Zealand commenced in the late 1940s with the creation of the Animal Ecology Section, Department of Scientific and Industrial Research (DSIR). Field surveys of rodents were backed by study skins and skeletal material. Supplemented by specimens from the Wildlife Service and the public, these accrued over the next 45 years laying the foundation for our present knowledge of rodent distribution. In 1951, J. S. Watson joined the DSIR from the Bureau of Animal Population, Oxford, and brought much needed experience in rodent biology and control. Publications followed on the identification, distribution and interrelations of rodents with native fauna, but such research waned temporarily following his death in 1959. In the early 1960s, Forest & Bird Protection Society members and the Wildlife Service used pre-packaged warfarin baits to control rats on small islands in the Hauraki Gulf, but the full significance of these operations was not understood for many years, it being widely held that complete extermination of rats was impossible. The 1964 ship rat invasion of Big South Cape Island and subsequent extinctions of endemic birds and bats sent shock waves through conservation circles and led to an increased interest in the ecology of rodents and their impact on native species. The mid-1960s saw the start of intensive research into Norway and ship rats. The next decade was one of intensified research culminating in the historic 1976 Department of Lands and Survey symposium on the Ecology and Control of Rodents in New Zealand Nature Reserves, further boosting interest in rodent distribution, food habits, reproduction, dispersal ability, interspecific competition, interactions with other species, and the steady development of eradication techniques now employed worldwide.