Determination of Age of Indigenous Rats in Australia

Abstract

A means for determining the age and development of the Australian bush rat (Rattus fuscipes) and the long haired rat (R. villosissimus) from eye lens weights is described in order to understand the population dynamics of these 2 groups. Males of both species were always larger than females but this was not reflected in lens morphology. R. fuscipes grew faster than R. villosissimus and this was not reflected in lens growth which was faster in R. villosissimus. This is attributed to the poorly illuminated coastal and subcoastal scrub environment in which the bush rat lives. The reliability of the results is discussed.