Phytophthora Dieback Reduces Quenda Digging in Western Australia's Jarrah Forests

A research team from Murdoch University has reported that the introduced plant pathogen Phytophthora dieback is indirectly affecting quenda (Isoodon obesulus) populations in Western Australia’s jarrah (Eucalyptus marginata) forests. Published in *Austral Ecology* under the title “Exotic Plant Pathogen Reduces Habitat and Foraging Activities of a Digging Mammal,” the study links the disease’s impact on vegetation to a measurable decline in the quality of the quenda’s habitat and a subsequent reduction in their digging behavior, a key activity for foraging and soil turnover.

The authors attribute the diminished digging activity to the loss of understory vegetation and leaf litter that Phytophthora dieback degrades, thereby limiting the cover and food resources that quendas rely on. Field observations across multiple jarrah sites showed a statistically significant correlation between disease severity, reduced habitat complexity, and lower rates of burrow construction. The findings highlight a cascading ecological effect of an exotic plant pathogen on a native mammal, suggesting that management of Phytophthora dieback could be essential for preserving the functional role of quendas within these forest ecosystems.