Authors: Tamara I. Potter, Aaron C. Greenville & Chris R. Dickman.

Great work by Tamara and her first paper from her Honours work!

Published in: Royal Society Open Science

Abstract:

Wolf spider (Lycosa spp.). Photo: T. Potter

Interspecific competition may occur when resources are limited, and is often most intense between animals in the same ecological guild. Intraguild predation (IGP) is a distinctive
form of interference competition, where a dominant predator selectively kills subordinate rivals to gain increased access to resources. However, before IGP can be identified, organisms must be confirmed as members of the same guild and occur together in space and time.

The lesser hairy-footed dunnart

Lesser-hairy footed dunnart (Sminthopsis youngsoni). Photo: T. Potter

(Sminthopsis youngsoni, Dasyuridae) is a generalist marsupial insectivore in arid Australia, but consumes wolf spiders (Lycosa spp., Lycosidae) disproportionately often relative to their availability. Here, we test the hypothesis that this disproportionate predation is a product of frequent encounter rates between the interactants due to high overlap in their diets and use of space and time. Diet and prey availability were determined using direct observations and invertebrate pitfall trapping, microhabitat use by tracking individuals of both species-groups, and temporal activity using spotlighting and camera traps. Major overlap (greater than 75% similarity) was found in diet and temporal activity, and weaker overlap in microhabitat use. Taken together, these findings suggest reasonable potential, for the first time, for competition and intraguild predation to occur between taxa as disparate as marsupials and spiders.

Reference:

Potter, T., Greenville, A.C. & Dickman, C.R. (2018). Assessing the potential for intraguild predation among taxonomically disparate micro-carnivores: marsupials and arthropods. Royal Society Open Science, 5: 171872.

Media:

Marsupial species eats spiders to stop spiders eating insects, Australia’s Science Channel, May 2018.

The marsupial mouse eats its competitors (Dutch), Scientias, May 2018.

This dunnart has competition for food… so it just eats the competition, Australian Geographic, May 2018.