Microhabitat selection by small mammals in response to fire

Abstract

Understanding how fire influences animal behaviour, such as movement and resource selection, is important for ecosystem management because it can improve our capacity to predict how species will respond. We assessed microhabitat selection by two small mammals, the bush rat (Rattus fuscipes) and agile antechinus (Antechinus agilis), in response to a low intensity prescribed fire. We used spool and line tracking and touch pole vegetation surveys to quantify microhabitat selection along 21 trails for bush rats and 22 for antechinuses before and after fire. In unburnt areas, bush rats showed positive selection for sedges, logs, and habitat complexity, with selection further increasing in burnt areas for sedges, ferns, shrubs, habitat complexity and unburnt patches. Agile antechinuses showed no significant microhabitat selection in unburnt or burnt areas and no change in response to fire. Their lack of response to ground fires may be due, partially, to their scansorial behaviour and use of tree hollows as refuge sites. Strong selection by bush rats for small unburnt patches suggests that even low intensity, patchy fires such as planned burns can impact bush rats and that high burn patchiness may help bush rats persist in recently burnt areas. Future fire planning should consider both behavioural and population responses of animals to fire.

Very small collars: an evaluation of telemetry location estimators for small mammals

“…Our approximate 6-7 m of location error was at the lower end of that range and closely approached the suggested distance of 5 m to maintain accuracy given our study area size (60.7 ha) and relative patch sizes (~ 5-10 ha) [46]. Current in-depth resource selection studies of small mammals using micro-VHF devices are limited and even fewer have detailed telemetry error assessments [1,15,17,23,31,32,76]. Therefore, it was difficult to gauge what distance would create an impactful bias in a small mammal study.…”

“…Because of differences in size, overlap, and perimeter-to-area calculations, different programs identified different dominant cover types or significant changes in percentage of land cover type across the KDE home ranges. While that difference is logical, it is worthy of consideration given the scale of and impact to small mammal resource selection analyses [31,32,76]. For animals that utilize such small spaces, in variable habitats, this could be highly impactful to a study's findings and conclusions.…”

“…Over the last decade, researchers have continued to develop radio telemetry equipment for small mammals, and VHF collars remain a cost effective, preferred method of collecting locational information on small mammals that were under heavy forest canopies, burrow underground, or spend any time underwater [12,27]. Recent advances in micro-VHF trackers (< 1.0 g) are enabling more accurate estimates of small mammal movements, resource selection, seasonal effects, territorial behaviors, and microhabitat use [27][28][29][30][31][32]. While these advancements in micro-VHF trackers are enabling us to address ecology and management needs of small mammals, there remain considerable limitations in tracking methodology for micro-VHF devices.…”

Experimentally testing animal responses to prescribed fire size and severity

“…By the same token, the burns at both properties may have been of insufficient size or severity to negatively affect the capture rates of Ctenotus grandis and C isolepis, both of which have shown a negative response to fire in previous studies (How & Dell, 2004;Masters, 1996). Low-severity, patchy fires are often promoted as a favorable management approach because they can retain shelter and other resources that allow animals to either persist in recently burned areas or survive until they emigrate to more suitable habitat (Lees et al, 2022;Silveira et al, 1999). There is some evidence to support this for small mammals in tropical savannas (Leahy et al, 2015;Shaw et al, 2021) and temperate woodlands (Swan et al, 2016), but corresponding evidence from arid grasslands is lacking.…”

Fire as a driver and mediator of predator–prey interactions

“…In response to heightened risk of predation in recently burnt habitat, many prey species alter their habitat use for foraging, resting, and predator avoidance. For example, in the forests of south‐eastern Australia, bush rats avoided burnt vegetation in favour of unburnt patches, increased their use of structurally complex habitat, and made more convoluted movements when foraging (Fordyce et al ., 2016; Lees et al ., 2022). The authors suggested that these behavioural changes were, at least in part, driven by heightened levels of perceived predation risk in burnt forest.…”