Laying low: Rugged lowland rainforest preferred by feral cats in the Australian Wet Tropics

• Published in: Ecology and evolution 2022-07, Vol.12 (7), p.e9105-n/a
• Main Authors: Bruce, Tom, Williams, Stephen E., Amin, Rajan, L'Hotellier, Felicity, Hirsch, Ben T.
• Format: Article
• Language: English
• Subjects: Animal control; Applied Ecology; Aridity; camera‐trap; Cats; Climate change; Climate change models; Climate models; Colonization; Conservation Ecology; Elevation; Encroachment; Environmental factors; Felis catus; Feral populations; Forests; Habitats; Indigenous species; Invasion Ecology; Mammals; national park; National parks; occupancy; Population decline; Prey; Rainforests; Refugia; Roads; Ruggedness; Surveys; topography; Tropical environments; Weather; Wildlife conservation; Zoology
• ISSN: 2045-7758; 2045-7758
• DOI: 10.1002/ece3.9105

Invasive mesopredators are responsible for the decline of many species of native mammals worldwide. Feral cats have been causally linked to multiple extinctions of Australian mammals since European colonization. While feral cats are found throughout Australia, most research has been undertaken in arid habitats, thus there is a limited understanding of feral cat distribution, abundance, and ecology in Australian tropical rainforests. We carried out camera‐trapping surveys at 108 locations across seven study sites, spanning 200 km in the Australian Wet Tropics. Single‐species occupancy analysis was implemented to investigate how environmental factors influence feral cat distribution. Feral cats were detected at a rate of 5.09 photographs/100 days, 11 times higher than previously recorded in the Australian Wet Tropics. The main environmental factors influencing feral cat occupancy were a positive association with terrain ruggedness, a negative association with elevation, and a higher affinity for rainforest than eucalypt forest. These findings were consistent with other studies on feral cat ecology but differed from similar surveys in Australia. Increasingly harsh and consistently wet weather conditions at higher elevations, and improved shelter in topographically complex habitats may drive cat preference for lowland rainforest. Feral cats were positively associated with roads, supporting the theory that roads facilitate access and colonization of feral cats within more remote parts of the rainforest. Higher elevation rainforests with no roads could act as refugia for native prey species within the critical weight range. Regular monitoring of existing roads should be implemented to monitor feral cats, and new linear infrastructure should be limited to prevent encroachment into these areas. This is pertinent as climate change modeling suggests that habitats at higher elevations will become similar to lower elevations, potentially making the environment more suitable for feral cat populations. Feral cats are responsible for the decline of multiple native species both globally and in Australia. However, we know very little about their ecology in tropical rainforests. This study demonstrated despite predictions of cats being absent from wet complex habitats, feral cats were present in all national parks surveyed and prefer low elevation, rugged terrain in rainforests.