Prescribed fire creates an ecological trap for a mycophageous mammal
Mark Le Pla 1,2, Bronwyn A. Hradsky 1, Julian Di Stefano 1, Tamika C. Farley-Lehmer 1,2, Emma K. Birnbaum 2 and Jack H. Pascoe 1,2.
1 Quantitative & Applied Ecology Group, School of Agriculture, Forest and Ecosystem Sciences,
University of Melbourne, Parkville, Victoria, Australia, 3010.
2 The Conservation Ecology Centre, Cape Otway, Victoria, Australia, 3233.
Fire offers both opportunities and risks for many species. Its impacts will depend on the scale of the fire, the animal’s movement decisions and capacity, and how fire alters the distribution and abundance of key resources.
The long-nosed potoroo (Potorous tridactylus) is a vulnerable marsupial which often resides in areas frequently exposed to fire. Inappropriate fire regimes and invasive predators are major threatening processes for P. tridactylus, and these predators may be more effective in the post-fire environment.
We present a before-after control-impact experiment describing the influence of prescribed fire on P. tridactylus. We fitted GPS collars to 52 individuals at nine independent sites to test if exposure to prescribed burning altered their survival and movement behavior.
Prescribed fire significantly reduced P. tridactylus survival in the immediate post-fire period and survival probability was negatively associated with increasing burn exposure. In contrast, home range size and movement rate remained largely unaffected on average. Site fidelity was very high: individuals rarely moved their home ranges after fire.
P. tridactylus selection for recently burnt areas varied, with some evidence of attraction to burnt areas at low levels of burn exposure and avoidance at higher exposure levels.
The poor survival and limited changes in movement behavior after fire suggest recently burnt areas may be an ecological trap for P. tridactylus: areas that are attractive yet confer lower fitness outcomes.
We suggest P. tridactylus may benefit from smaller burn patches, retention of structurally complex vegetation, and the integration of invasive predator control with prescribed burning.