Date of Award

2004

Degree Type

Thesis

Degree Name

Bachelor of Science Honours

Faculty

Faculty of Computing, Health and Science

First Advisor

Dr Alan Needham

Second Advisor

Dr David Pearson

Abstract

Seasonal fluctuations in rainfall and food availability are thought to change populations of arid zone mammals dramatically over time. Competition between similar species for limited food resources is believed to be a major factor in the evolution and maintenance of population assemblages. Animals foraging in arid regions must be responsive to the unreliable distribution of nutrients and food resources to ensure the survival of viable populations. Adaptive physiological traits and behavioural mechanisms of arid zone animals allow them to survive extreme conditions and the ability to switch between prey species in adverse conditions is an advantageous strategy. This study was conducted in Mt Keith, Western Australia and investigated the diet of two dasyurid marsupials D. cristicauda and N. ridei. The project was designed to determine if seasonal changes were present in the diet of D. cristicauda and N. ridei, construct a reference collection of local invertebrates, compare the availability of captured fauna with faecal material and detennine the efficiency of different pitfall traps for capturing prey. Results have shown that both D. cristicauda and N. ridei are predominantly insectivorous and select similar prey types, although the frequency in which prey types are observed in faecal pellets differed between the two species. Differences were also recorded between prey frequency and time of sampling for each species. When comparing different pitfall traps to determine efficiency, capture rate of potential prey changed in response to trap type and season. This study concurs with other research, whereby seasonal shifts in diet were reported in D. cristicauda populations in both the Simpson Desert and in central Australia. These dietary changes were attributed to changes in the availability of potential prey, due to the influences of season and drought; and changes in the selection of prey in response to balancing the costs of reproduction. The ability of these animals to switch between prey sources is advantageous in arid regions where resources fluctuate in response to climatic changes.

Included in

Zoology Commons

Share

 
COinS