How many foxes do we have roaming the Nullaki? Are the feral cats widespread, or confined to certain areas? Do we have bandicoots wandering around at night? Are the rabbits really worse than in previous years?
To answer these and other questions, WICC and Nullaki Conservation Initiative have implemented a plan to provide a consistent methodology for monitoring native and feral fauna on the Nullaki. The plan is also a requirement of grants we have received to carry out our sustainable biodiversity efforts. The tools of the plan are technical (camera traps and computer analysis), and human (WICC staff, NCI volunteers, landowners, and Aboriginal Rangers).
We have overlaid a grid onto the Nullaki map, dividing it into 18 sectors. Each of these sectors will (or already does) house a camera trap. The specific site is based on access, owner permission, and location to provide an even spatial coverage of the Nullaki. Some areas (the Wilson Inlet sandbar, along the feral management fence) may be given special attention.
Once a site has been selected for a camera trap, it must be prepared. Since the cameras are motion-activated, excess vegetation is trimmed to reduce ‘false triggers’. The camera is mounted securely about 40 cm from the ground, facing South where possible to reduce the effect of moving shadows as the sun passes. The cameras have an infra-red flash, to allow capturing images at night without disturbing the target animals.
About every 30 days, the cameras will be serviced. This involves swapping out and labelling the memory cards, changing the batteries, inspecting the site and camera for any needed attention, and making sure the date is correct! The cameras have a pesky habit of reverting the date back to default settings.
Now that we have data (digital images with date and location), it is time to make sense if it! The first task is to cull out the false alarms. There is a trade-off between being able to detect small mammals (mardos, bushrats), and accepting that windblown branches will trigger the camera too. This job is efficiently and gratefully performed by the Southern Aboriginal Corporation’s Aboriginal Ranger team, who also do some of the camera servicing.
After the unwanted images are deleted, the ‘good stuff’ is uploaded to the WICC server, where it is imported into a database, CPW Photo Warehouse, a widely used program which is distributed free by Colorado Parks & Wildlife in the US. The images are loaded by site and visit date, than reviewed by WICC staff, who identify any native or feral animals seen. This is done twice by two different operators for accuracy. Once this data is collated, it is time to run reports, eg:
- how many fox images are captured over a given time span at all sites?
- at which sites do cats appear?
- is there a trend over time in feral sightings?
- are there different results in baited versus non-baited areas?
- how do results compare with data from outside the fence?
- which native fauna are present, what areas do they frequent?
With answers to these types of questions, we will be better able to assess the magnitude of our feral problem, possible trends (or cycles) in their numbers, and inform our feral management controls/efforts. In 2017, NCI (then NCG), obtained 3 camera traps as part of our successful State NRM Grant. From those humble beginnings, we hope to greatly improve our understanding of just who we are sharing this peninsula with.
Thanks to the Department of Biodiversity, Conservation and Attractions (DBCA) for providing initial and ongoing review of this monitoring plan.