temperament studies of animals can provide unique insight on how behaviour, genetics and environmental factors interact to influence the evolution and dynamics of populations. this, in turn, can be used to predict how individuals may respond in a variety of situations such as manipulations to habitat and resources, as well as increased predation risks, all of which are likely to be modified by future climate change. this thesis explored the behaviours of meadow jumping mice (zapus hudsonius) from a sample of animals captured in northwestern ontario. the data were collected using open-field tests that quantified-sniffing, scanning, walking, running, rearing, jumping, grooming, stillness and inspecting objects within the arena. a single principal component described a cline of behaviour ranging from motionless ‘frightful’ animals at one end to highly active and agitated individuals at the other. the interpretation is consistent with the description of anti-predator adaptations used by jumping mice.