Mammal responses to moderate-intensity planned burning in a small, isolated woodland reserve

Abstract

ContextFire management advice for fauna conservation in protected areas must often be based on expert opinion and extrapolation from very few scientific studies. More monitoring and research are needed to better inform land managers tasked with both managing for biodiversity and managing the threat of bushfires. AimsTo document changes in the activity of native and introduced mammal species in response to planned burns in a small, isolated woodland reserve in Tasmania. MethodsOver a 10-year period, mammal activity was monitored before and after two separate moderate-intensity planned burns in 20-ha management blocks and in unburnt blocks of similar size by using live-trapping and camera-trapping. Vegetation density was monitored concurrently, and we also searched burnt areas for animals killed by fire. Key resultsThe activity of most mammal populations was largely unaffected by the two planned burns. However, during one of the burns, over 20 rufous-bellied pademelons were directly killed as a result of a need to conduct a backburn. The population recovered after 3 years. The activity of red-necked wallabies, common brushtail possums and short-beaked echidnas generally increased across the whole study area during the 10-year monitoring period. Limited evidence suggests that eastern barred bandicoot and European rabbit activity increased after fire. No swamp rat activity was recorded in burnt areas following the planned burns. Unexpectedly they did not recolonise burnt areas and also ceased to be active in control areas for the last 3 years of the study; we hypothesise that this may be due to the increased dryness and thinning of vegetation. ConclusionsWe found that most of the mammal populations within this small, isolated reserve were resilient to the planned burning program, with no or limited short-term effect for all but one species. The absence of swamp rats from burnt or unburnt areas for the last 3 years of our study suggests that factors other than fire are also affecting this species. ImplicationsPlanned burning is an important tool for biodiversity conservation, but its use needs to be underpinned by empirical data because mammal fire responses are likely to be site-, time- and context-specific.

Species distribution modelling of the endangered Mahogany Glider (Petaurus gracilis) reveals key areas for targeted survey and conservation

“…Fire management in Mahogany Glider habitat usually consists of planned burns in the understory, and this fine‐scale, below‐canopy burning may not be detected by satellite remote sensing that aims to detect wildfire of larger scale and higher intensity. The impact of fire on mammal species has been found to be complicated and dependent on site, context and other factors (Driessen et al, 2021). Our modelling did not adequately incorporate the role of fire in habitat suitability, and it requires further investigation.…”

“…An updated SDM for Mahogany Gliders is recommended once more recent sighting records accumulate and more advanced spatial data are available. Spatial data that could better refine the models include additional fine‐scale fire layers (Driessen et al, 2021), mapping of forest age or structure, to capture important factors such as abundance of tree hollows (Linnell et al, 2017), mapping of the impact of recent extreme weather events, in this case cyclones (Bateman et al, 2012) and mapping of thin lines of roadside vegetation that may act as species dispersal or movement corridors (Vasudev et al, 2015). Additionally, the SDM could be used to model the potential effect of climate change on Mahogany Gliders, as done for other possums and gliders (Handayani et al, 2019; Molloy et al, 2013), but noting that post‐model refining from expert knowledge (e.g.…”

“…An updated SDM for Mahogany Gliders is recommended once more recent sighting records accumulate and more advanced spatial data are available. Spatial data that could better refine the models include additional fine-scale fire layers (Driessen et al, 2021), mapping of forest age or structure, to capture important factors such as abundance of tree hollows (Linnell F I G U R E 5 Histogram showing the number of patches within patch size bins, split by patches with Mahogany Glider sighting records (black) and without a record (red). The minimum estimated home range of a male Mahogany Glider is about 0.1 km 2 (11 ha) (Jackson, 2000a(Jackson, , 2000b, so we consider patch sizes <0.1 km 2 unlikely to support a population.…”

Identifying important environmental variables in the niche partitioning of two keystone ecosystem engineers (Bettongia gaimardi and Potorous tridactylus) in Tasmania

“…Conversely, these features may make moving through dense vegetation difficult. Therefore, dense habitats may favour P. tridactylus rather than B. gaimardi , such as at the Peter Murrell Reserves, south of Hobart (Driessen and Jarman 2014; Driessen et al . 2021).…”

“…Conversely, these features may make moving through dense vegetation difficult. Therefore, dense habitats may favour P. tridactylus rather than B. gaimardi, such as at the Peter Murrell Reserves, south of Hobart (Driessen and Jarman 2014;Driessen et al 2021). Furthermore, the smaller home range of P. tridactylus and unwillingness to go far from dense vegetation, makes it more suited than B. gaimardi to the wet and infertile western half of the state where truffle density is likely to be higher.…”