Mammalian faunal collapse in Western Australia, 1875-1925: the hypothesised role of epizootic disease and a conceptual model of its origin, introduction, transmission, and spread

Abstract

Information relating to the early decline of native mammal species in the western third of Australia, before the establishment of rabbits and foxes, was sought from recollections of oldtimers, archival records, historical documents, and searches of museum collections. Based on the information discovered, the hypothesis is advanced that the early decline was caused by an exotic disease. The evidence available is suggestive of a first wave of mammal declines and extinctions in Western Australia (WA) commencing about 1875. From this single, contingent historical event, it is postulated that 33 species (about one third of the non-volant mammal fauna of WA) changed significantly in distribution and abundance.The pattern of the decline both geographically and over time is consistent with epizootic disease as the primary factor, but probably interacting with drought and predation by feral cats as secondary factors. Much of the decline occurred before food shortages or habitat destruction caused by sheep grazing,...