Intraguild predation among marsupials and arthropods

Foraging is a fundamental behaviour that enables animals to meet their energy and nutrient requirements. However, as food resources are limited, competition arises between foragers seeking to acquire them. Different species will often resolve this competition by exploiting a niche or consuming those shared resources differently across time and/or space. Intraguild predation (IGP), however, is a distinctive form of this competition. IGP occurs when a dominant predator selectively kills and eats smaller rivals to gain increased access to the food resources that they share. This kind of interaction has been well documented for carnivores within the same Order (for example, wolves and coyotes, and lions and hyenas); however, few studies have examined IGP between predators from very different taxonomic groups. In this case, we investigated selective predation by a mammal on an arthropod that has a very similar diet. The lesser hairy-footed dunnart is a common insectivorous marsupial in arid Australia that consumes wolf spiders disproportionately often compared to their availability. We investigated the reasons behind this interaction and found that the dunnarts prey on wolf spiders in order to reduce competition for shared food resources