Data from: Impact assessment of the Australian 2019-20 megafires on roost sites of the vulnerable grey-headed flying-fox (Pteropus poliocephalus)
Data files
Sep 13, 2024 version files 121.15 KB
Abstract
Bushfires are a natural component of the ecology of many landscapes, but megafires such as those experienced in Australia between July 2019 and April 2020 have substantial direct and indirect impacts on wildlife. Following these megafires, bushfires have begun to be considered a significant emerging threat to the vulnerable grey-headed flying-fox (Pteropus poliocephalus). In this study, we quantified the impact of the 2019-20 megafires on all known roost locations of the species by (1) determining the number of roosts within burnt areas represented by three fire severity mapping products, (2) classifying burnt roosts according to the severity with which they burnt, and (3) examining the distribution of distances to the nearest burnt areas for unburnt roosts. Our findings indicate that the impacts of the 2019-20 megafires on roosting habitat of the grey-headed flying-fox have hitherto been underestimated. Of 874 known grey-headed flying-fox roosts, we found that 134 roosts were situated within burnt areas, equating to 15% of the species’ roost locations. Depending on the mapping products applied, part or all canopy vegetation was severely burnt in 27-36% of burnt roosts, while in 11-14% of burnt roosts, the canopy vegetation was burnt entirely. Of the 740 unburnt roosts, 50% were located within 6.85 km from burnt areas, suggesting that at a substantial number of roosts flying-foxes were also indirectly affected by the fires, through the effects of smoke on roosting and locally foraging individuals, and through destruction of local foraging resources from burning. We discuss the implications of these findings for the conservation management of this vulnerable species.
README: Impact assessment of the Australian 2019-20 megafires on roost sites of the vulnerable grey-headed flying-fox (Pteropus poliocephalus)
https://doi.org/10.5061/dryad.fbg79cp2z
The dataset consists of an excel spreadsheet listing all known grey-headed flying-fox roost locations prior to the 2019-20 megafires in Australia.
Description of the data and file structure
The dataset consists of:
- the National flying-fox monitoring program number of the flying-fox roost location (if applicable; NFFMPCampID),
- the State the roost is in (State),
- the latitude and longitude location of the roost site (Lat, Long),
- the roost type, which refers to whether the roost has been ground-truthed or whether it has been identified from telemetry data but not yet ground-truthed (Type),
- the class of the roost; ‘Class 1’ roosts were visited by a single tracked individual during a single day; ‘Class 2’ roosts were visited by a single tracked individual over multiple days; and ‘Class 3’ roosts were visited by multiple individuals (thus providing strong evidence for the presence of a ‘colony’) (RoostClass).
- the distance to the NIAFED shapefile in km (dist_NIAFED)
For GEEBAM:
- the GEEBAM fire severity class for the point location of a roost (GEEBAM_pt) (NA means outside the burn area or no data),
- the corresponding fire severity class for the point location of a roost (GEEBAM_pt_category) (NA means outside the burn area or no data),
- the maximum fire severity value within 100m of the roost point location (max_GEEBAM_buffer),
- the proportion of the 100m buffer around the roost that was 'burnt' (prop_burn_GEEBAM_buffer),
- then the proportion of the 100m buffer around the roost in which the canopy was burnt (prop_canopy_burn_GEEBAM_buffer),
For FESM:
- the FESM fire severity code for the point location of a roost (FESM_pt) (NA means outside the burn area or no data),
- the corresponding fire severity class for the point location of a roost (FESM_pt_category) (NA means outside the burn area or no data),
- the maximum fire severity value within 100m of the roost point location (max_FESM_buffer),
- the proportion of the 100m buffer around the roost that was 'burnt' (prop_burn_FESM_buffer),
- the proportion of the 100m buffer around the roost in which the canopy was burnt (prop_canopy_burn_FESM_buffer),
For the Victorian Fire Severity map:
- the Victorian Fire Severity fire severity code for the point location of a roost (Vic_severity_pt) (NA means outside the burn area or no data),
- the corresponding fire severity class for the point location of a roost (Vic_severity_pt_category) (NA means outside the burn area or no data),
- the maximum fire severity value within 100m of the roost point location (max_Vic_severity_buffer),
- the proportion of the 100m buffer around the roost that was 'burnt' (prop_burn_Vic_severity_buffer),
- the proportion of the 100m buffer around the roost in which the canopy was burnt (prop_canopy_burn_Vic_severity_buffer).
The final columns indicate:
- the proportion of the buffer surrounding a roost that was burnt according to FESM (prop_burn_FESM_buffer_cat),
- the proportion of the canopy surrounding a roost that was burnt according to FESM (prop_canopy_FESM_buffer_cat),
- the proportion of the buffer surrounding a roost that was burnt according to GEEBAM (prop_burn_GEEBAM_buffer_cat),
- the proportion of the canopy surrounding a roost that was burnt according to FESM (prop_canopy_GEEBAM_buffer_cat).
Methods
This dataset involves the locations of 874 grey-headed flying-fox roost locations, and their spatial relationship to three fire severity mapping products.