Aim 3. Vulnerability of Australian bat populations to WNS
Vulnerability mapping
We will incorporate mechanistic links between Pd exposure (at the landscape, hibernacula, and microhabitat scales) and sensitivity (as predicted by physiological and behavioural traits for different populations) to map spatiotemporal variation in the vulnerability of the key bat species to WNS. To achieve this, we will adapt biophysical modeling algorithms applied to predict WNS consequences among North American bats. This model uses estimates of winter energy expenditure to predict the change in maximum duration of hibernation caused by exposure to Pd as a function of species-specific traits and environmental conditions.
This outcome provides key information for our partner organisations (Commonwealth and State wildlife biosecurity and conservation agencies) to prepare for and respond to the imminent threat posed by WNS to Australia’s bat fauna.
This outcome provides key information for our partner organisations (Commonwealth and State wildlife biosecurity and conservation agencies) to prepare for and respond to the imminent threat posed by WNS to Australia’s bat fauna.
Population monitoring
Currently, monitoring of regional populations of cave-roosting species is primarily restricted to the critically endangered southern bent-winged bat, with occasional exit counts at a few caves for eastern bent-winged bats and eastern horseshoe bats. We will lead the way, in collaboration with partner government agencies, to set-up systems for monitoring bat populations at high priority sites. Obtaining baseline data on population numbers is critical, prior to any potential impact of WNS, and will inform models of the risk of exposure to Pd (Aim 1). We will use two main methods for estimating population densities:
i) counting of bats both within roosts and during emergence using thermal imagery and tracking/counting software (recently developed by CI Lumsden), and ii) marking of large samples of individual bats (~1000 per regional population) using passive integrated transponders (PIT-tags) and automated monitoring of recapture/presence using custom PIT-tag reader/logger stations (recently developed by CI Lumsden).
Additionally, it will be important to assess bat movements between caves to estimate populations (above) and inform Pd transmission models (Aim 2). Having PIT-tagged 1000s of bats we will use PIT-tag reader/datalogger stations recording presence data simultaneously across different cave roosts. These data will provide valuable information on movements at different temporal and spatial scales. The tagging of large numbers of bats will require the assistance of teams of qualified volunteers (e.g. Australasian Bat Society members, university students).
i) counting of bats both within roosts and during emergence using thermal imagery and tracking/counting software (recently developed by CI Lumsden), and ii) marking of large samples of individual bats (~1000 per regional population) using passive integrated transponders (PIT-tags) and automated monitoring of recapture/presence using custom PIT-tag reader/logger stations (recently developed by CI Lumsden).
Additionally, it will be important to assess bat movements between caves to estimate populations (above) and inform Pd transmission models (Aim 2). Having PIT-tagged 1000s of bats we will use PIT-tag reader/datalogger stations recording presence data simultaneously across different cave roosts. These data will provide valuable information on movements at different temporal and spatial scales. The tagging of large numbers of bats will require the assistance of teams of qualified volunteers (e.g. Australasian Bat Society members, university students).