Niche overlap between marsupial and eutherian carnivores: does competition threaten the endangered spotted-tailed quoll?

The significance of top-down regulation by carnivores is receiving increasing global recognition. As a consequence, key objectives in many programmes that seek to maintain ecosystem function now include conserving carnivores and understanding their interactions. This study examined overlap in resource use (space and diet) of introduced eutherian carnivores and an endangered marsupial carnivore, the spotted-tailed quoll Dasyurus maculatus, in eastern Australia. We also investigated mechanisms of niche partitioning and evidence for interspecific aggression.

Dietary overlap between quolls, red foxes Vulpes vulpes and wild dogs Canis familiaris was assessed by analysis of scats. Trapping, radio-tracking and direct observations were used to quantify spatial overlap between quolls, foxes, wild dogs and feral cats Felis catus.

Dietary overlap among the carnivores was extensive. Medium-sized mammals were the most important prey for all three predators, indicating potential for exploitative interactions. However, hunting of different size classes of secondary prey and consumption by quolls of more arboreal prey than their counterparts may assist coexistence. Remains of quoll were found in two dog scats, and cat hair in another, possibly indicating intraguild predation.

Author A. S. Glen, C. R. Dickman
Date 19/03/2008
Year 2008
Secondary title Journal of Applied Ecology
Volume 45
Number 2
Institution University of Sydney
Department School of Biological Sciences
Pages 700-707
Notes Notes
ISBN/ISSN doi:10.1111/j.1365-2664.2007.01449.x