Behavioural and physiological traits of the endangered marsupial, the northern quoll (Dasyurus hallucatus)

Date: 07, Sep, 2021
Author(s):   Natalie Jean Freeman
Publisher: The University of Queensland

PhD Thesis

Selection favours organisms that survive to produce offspring. To achieve this, animals have evolved a variety of life history strategies, with variation in lifespan, number of reproductive events and number of offspring among species. In recent years, the pace-of-life syndrome (POLS) theory has been used to integrate physiology and behaviour with life history to help explain the differences in reproductive strategies among species. For example, species with a ‘fast’ pace-of-life are generally small in size, reproduce early, and have a short lifespan, and predicted to have associated high metabolism and performance. To fuel such a ‘fast’ pace-of-life, individuals may also make corresponding foraging decisions that balance increased needs for energy against predation risk. Animals can modify their predation risks when foraging using changes in vigilance and activity. Thus, physiological traits and foraging decisions are predicted to covary to influence an individual’s survival and reproductive success. In species where the sexes have different reproductive strategies, POLS predicts corresponding differences in physiological and behavioural traits.

Using the endangered northern quoll (Dasyurus hallucatus), we explored if there were differences in foraging behaviour and physiology. Males of this species are approximately double the mass of females at maturity, and have a 100% mortality rate shortly after their single breeding season while females can breed for multiple years (facultatively semelparous). As such, the sexes differ greatly in their energetic demands due to both their sexual dimorphism and life history strategies.

In summary, I found that male northern quolls took more risks while foraging. An individual’s GUD was the most repeatable foraging behaviour. Our findings did not support the POLS theory that RMR and sprint speed are associated, nor that sex would affect either of these traits. Finally, we report the novel finding of sociality among female northern quolls, behaviour that may be absent from mainland populations because of low population densities.