menno's blog

Banks Peninsula 2050 Predator Free Initiative

On November 4 2018, the Cacophony Project was privileged to become a signatory of the Banks Peninsula 2050 Predator Free Initiative. Along with key personnel from DOC, Ecan, Christchurch City Council, Banks Peninsula Iwi and Banks Peninsula Conservation Trust, the Cacophony Project's Clare McClennan was present to participate in the signing ceremony held at the Living Springs amphitheater. This historic partnership aims to focus and coordinate efforts to eliminate invasive predators on Banks Peninsula.

Birdsong monitoring at Sandspit

This article comes to us from Tim Armitage who has recently installed a Cacophonometer at his property to help monitor the effects of predator controls.

Cacophonometer in the wild

Early October 2018 we received our Cacophonometer at our Sandspit home. The setup process was very simple with the app having been pre-installed and the main next steps being getting our account created online and the device registered. The location we chose was around 20 meters from our house (a site with power available) and a small WiFi extender soon fulfilled the coverage required to ensure the upload process was reliable. We soon had plenty of recordings to sample with the ‘meter following the pattern set by the software – i.e. greater intensity of records around dawn and dusk.

Battery & Audio Support

Internals of the new hardware

The last couple of months have seen us make more improvements to our Cacophonator hardware. The changes made have been driven by the demands of upcoming projects and targets.

Up until now we've typically run our devices on mains power. We've preferred sites which are near native bush but have access to a wall socket (sometimes with long extension cords!). This has gotten us quite far in terms of testing our prototypes and gathering footage to train our machine learning classifier but obviously isn't going to be a long term solution. Being able to run on battery power opens up a huge range of new areas to our devices.

The Cacophonator hardware now incorporates a buck-boost converter which allows it to work from a number of types of power sources including various battery technologies with differing output voltages (which change as the battery discharges). The buck-boost converter also continues to support mains power using a classic "wall wart" AC adapter.

New battery packs

We explored a number of options for battery power and after a number of false starts and experiments we've found a New Zealand based manufacturer who will make weatherproof lithium-ion battery packs which meet our needs exactly. These packs have performed well in the cold and in heavy rain. A Cacophonator can run for 5-6 nights (turning off during the day) on a single battery pack and we have ideas on how to extend battery life further.

Accelerating tagging using machine learning classification


We now have many thermal cameras deployed at various locations collecting recordings every night. This means we have a lot of thermal video footage to manually tag every day so that they can be used to improve our machine learning classifier. As I write this, we have collected almost 30,000 thermal video recordings.

Our recordings include many false positives - where a non-animal object triggered our camera's motion detector. We also have many, many recordings of birds - particularly at dawn and dusk. Filtering through all the false positives and bird footage is very time consuming.