FACT SHEET: NUMBER TWO
CANE TOAD W.A. / N.T. FRONTLINE CORRIDORS
CANE TOAD NT ( Northern Territory) FRONT LINES GENERALLY
Consistent KTB reconnaissance and toadbusting for 3 and a half years at cane toad front line corridors in the west of Northern Territory reveals a complex variable frontline made up of multiple corridors, not previously identified or understood.
When KTBs started their campaign westerly, south westerly and north westerly invasion toads were initially identified by KTBs as in 10 corridors all of which the KTBs worked in, and which that have now amalgamated into 6 wetland corridors.
Inputting KTB front line weekly data (recorded and accumulated since September 2005), into an epidemiological program is critical for predictive modelling of cane toad westerly movement across the north of Australia. This understanding of how toads colonise, what triggers their breeding, what type of habitats are preferred for breeding is critical for determining what is going to happen in the Kimberley and WA generally. It is also critical in understanding cane toad movement across the whole of Australia.
HOW DOES A CANE TOAD FRONTLINE WORK?
Weekly field reconnaissance by KTBs since September 2005 has shown that males generally take the initiative to move forward, often in colonies of several hundred.
It has also been observed that these male colonising fronts often have lone or a few females randomly in front of them. The complexity of how cane toads invade, how many different calls the male makes, and what call males actually make when they want to attract females for breeding, must be better understood to enhance cane toad catching and control. Cane Toad management strategies must be in place prior to an invasion.
Clearly any research towards finding a biological solution also requires this knowledge.
KTBs COLLECT DATA
KTBs measure and take length of every adult cane toad they catch, and they record this data along with gender of each toad on KTB data collection sheets.
KTB DATA SHOWS?
It is clear to KTBs from their data collected from weekly reconnaissance and toadbusting since September 2005 that:
- The cane toad frontline is not a single or stable frontline, but a series of variable fronts in several but varying wet corridors
- Random mature female cane toads appear to generally advance first, thus possibly finding best habitats and possibly laying a pheromone (or other scent) trail so the males can find them (more field work is required to ascertain if this is actually the case)
- Older adult male toad populations (identified by the well worn pads on their feet) follow in vast numbers, and call when it appears that breeding conditions are perfect
- Initial breeding appears to take place within the frontline colonisers with some (selected) males and females staying behind to wait, possibly for the multi-gender group of toads to catch up
- Behind the almost all male population front is a multi gender, multi age male and female primary breeding colony. Toad busting these primary colonies is essential to prevent continuous breeding that sends forward wave after wave of new colonisers in vast numbers
- It might be that the first advance colonising mature female cane toads use the dry season to advance, settle and re-energise by taking sufficient food to provide enough energy for future opportunistic breeding
- Front line colonising cane toads are female and appear large and old; and maybe genetically programmed to move to non- cane toad invaded places? (or simply do not go where other female pheromones have been before?), and then move on soon after breeding?
- Weekly removal of these big female toads from frontlines by KTBs since September 2005 appears to have changed the behaviour and numbers of cane toads at front lines
- Decimating front line population numbers, by catching adult cane toads and spraying metamorph millions, reduces the otherwise massive toad number build ups at front lines
- We must reduce primary breeding colonies but they should not be confused with established breeding colonies much further behind where KTBs cannot work any longer and must leave to NT toadbusters.
KTB TOADBUSTING SITES
This map, a larger version of which is on this website, shows the KTB toadbusting sites since we started in September 2005, the mapped advance of the cane toad front lines in purple (as at November 2009) and the forward most cane toads infected with the lungworm parasite frontline in green.
KTBs GPS toadbusting sites and undertake reconnaissance prior to sending out toadbusting teams by helicopter, gyrocopter, boat, bus for the children, 4WD vehicles and cross country off road bikes