Technology has revolutionised the way we (as humans) keep record of our daily lives. Photos and video are now the perpetual wall paper in the background of our lives. Wildlife haven’t quite caught the selfie bug (or have they…), but the sneaky placement of video cameras in the middle of NZ’s wilderness can tell us a lot about the future of our wildlife. This was true for pest control monitoring in the Blue Mountains, West Otago.
Reducing the numbers of rats, stoats and possums was key to protecting endangered mohua and other native wildlife in the blue mountains area. This could be done through aerial 1080 pest control operations, but we wanted to know how effective this method was. So in 2014, scientists from DOC and Lincoln University set out to video the species living in the Blue Mountains before and after a Battle for our Birds aerial 1080 operation.
Hidden on the forest floor near trapping tunnels, 26 motion sensing, infrared cameras were placed to record the presence of pests, deer and birds. The cameras ran for a number of weeks before, during and after the pest control operations. When wildlife came into the range of the camera, a 30 second video was captured.
• The 1080 drop took place at week 14 and monitoring continued for a further 5 ½ weeks.
• For any bird species, we calculated their abundance in the 28 days before the poison operation and in the 28 days following the 1080 operation.
Dr Elaine Murphy was pleased at what the video captured. The footage reinforced the current value of aerial 1080 pest control for protecting our threatened species (especially the mohua) at large scale.
“It’s amazing what activity can be recorded on a camera that we don’t pick up using conventional tracking tunnels. Stoats and rats were regularly recorded on cameras but rats were almost always alone. Stoats visited regularly and were twice recorded in family groups of up to 6 animals.”
So what did this tell us?
We were amazed at how clear the monitoring results were – our usual method (of monitoring tracking tunnels) tells the same story but not quite so precisely.
In total 4792 videos of animals were recorded including huge flocks of finches (hundreds!) feeding on beech seeds. The stats showed no evidence of reduced bird numbers in the 4-weeks after the aerial 1080 operation. The mohua counts before the aerial 1080 operation suggested a decline in mohua numbers from the year before. By contrast, the count after the aerial 1080 operation was the highest since counts began in 2007.
After the aerial 1080 drop, the number of cameras recording stoats, rats, mice and hedgehogs was significantly lower. No stoats or rats were recorded the day after the operation or within the 38 days after the operation when the camera trial ended.
For the hunters, the good news was the apparent negligible impact of 1080 baits on the susceptible fallow deer population. That’s the deer repellent at work!
As New Zealand makes progress toward the ultimate goal of becoming predator free by 2050 and powerful field cameras become readily available, there will be more camera analysis possible. Rather than the demise of pests, those cameras will be recording growing native bird populations thriving in our forests.