Towsey, J., Goldizon, A., Fuller, R., Shanahan, D., Thornhill, I. The artificial links provided by elevated wires are important connecting features for urban possum populations. British Ecological Society Annual Meeting, Edinburgh International Conference Centre. 13-16th December 2015.
The process of urbanisation is a global phenomenon with multiple effects on biodiversity. Frequently referenced impacts are habitat fragmentation and destruction and species loss. However, a number of species have become well adapted to urban areas and in many cities some species have recolonized or continued to thrive. The reasons why some species fail whilst others succeed are not well established but must be better understood if the impacts of continued urban expansion are to be managed. Greater Brisbane is a highly diverse, sub-tropical region of Queensland, Australia. This study examines how two species of native possum, the ring-tailed (Pseudocheirus peregrinus) and brush-tailed (Trichosurus vulpecula) which have arboreal lifestyles, maintain healthy populations despite fragmentation of canopy cover within which they would spend most of their life-cycle. To do so, we collected possum presence/absence data from 60 streets along an urban land-use gradient (250m transects) over 8 sampling periods between 2012 and 2015 and compiled multivariate data for each street including the mean and total length of wire, the number of street poles, wire/vegetation interactions and various canopy related metrics. Factors contributing to possum presence or absence were investigated and possum abundance was modelled at street-level using a generalized linear mixed model (GLMM) approach. We found that both mid-level canopy cover and wire configurations contributed to possum abundance, though the specific factors differed for each species broadly in line with their ecology. Consequently, a gradual move to subterranean wire connections across Brisbane could have significant implications for urban possum populations.