A transmitter is fitted to a kākāpō
Every kākāpō wears a smart transmitter that sends out a radio signal. The signal describes the bird’s position, whether it’s still alive, and how much battery the transmitter has left. Males and females wear different versions of the transmitter which add behavioural information to the signal.
We put Egg Timer versions of the smart transmitters on female kākāpō. Each transmitter:
- records and analyses the amount the female moves over time
- adds a code to its standard radio signal, indicating whether the bird is nesting, and for how long if so.
We put Check Mate versions of the smart transmitter on male kākāpō. Each transmitter:
- records and analyses the amount the male moves over time.
If the movement if vigorous enough to suggest mating, the transmitter:
- records the level of movement during the mating
- switches on a mini receiver inside the transmitter.
The mini receiver:
- detects which female is present, and if so records which one
- detects the female’s level of movement during the mating and records it.
- adds a code to its standard radio signal, encapsulating the male’s behaviour and partner.
The information helps us manage nests and plan for any required artificial inseminations.
Sirtrack make the transmitters and upgrade the hardware. Wildtech does most of the programming.
Data logger with smart hopper, weighing station and handheld unit
Image: Stephen Martin | DOC
A kākāpō data logger is basically a portable box containing a radio receiver, data logger and special computer software package.
We place data loggers at strategic locations, such as the supplementary feeding stations. Then we use a handheld Bluetooth computer to download information from each data logger as needed.
Data loggers record the movements of any kākāpō within a 10 m radius. In the early days, we often used tracking dogs to find kākāpō – data loggers save us a lot of time.
Special long-range data loggers sit on high points around the islands. In the right conditions, they can pick up signals from transmitters 3 km away. They record the information and send it to us via satellites.
We can record the weight of any kākāpō feeding at a supplementary feeding station by linking a data logger to electronic scales beneath the hopper. The data informs our rationing plans to help each kākāpō reach and maintain an optimum weight for breeding.
Smart hoppers have mechanical arms, plugged into the data logger. The arm locks the lid shut unless a kākāpō wearing the right transmitter comes along. It makes food rationing more reliable.
During a breeding season, all kākāpō nests are closely monitored. Nest kits makes this process as smooth as possible.
An infrared beam crosses a kākāpō nest entrance
Image: Andrew Digby | DOC
At each nest, we install:
- a small infrared camera
- an infrared beam across the entrance
- a proximity sensor that detects any kākāpō nearby
- a data logger that all the other gear connects to
- a tent, 50 m away.
The data logger connects to a device at the tent, helping us detect when the kākāpō mother leaves her nest. That’s the best time to check on the chick.
The data logger also connects to the island’s main hut. Using a laptop at the hut, we take turns to monitor all the nests 24 hours a day. We can see which mums are good at incubating their eggs, which mums are spending too much time away from their chicks and if any other kākāpō are hanging around the nest. Young male kākāpō and seabirds sometimes enter nests and injure the chicks. The proximity sensor detects those male kākāpō and anything entering the nest breaks the infrared beam.
A smart trap on the move
Image: Andrew Digby | DOC
Occasionally, a transmitter will stop working or simply fall off its kākāpō host. To find transmitter-less kākāpō, we use smart traps.
Every kākāpō has a microchip inserted under its skin. It provides a fool-proof way to identify each bird. We can program a smart trap to trigger only when it detects a specific microchip number. When the trap goes off, it sends a message to a nearby ranger who collects the bird as soon as possible.
In 2010, a batch of kākāpō transmitters failed, preventing us from monitoring 21% of the kākāpō population. Without management, kākāpō nests have a very low chance of success, so it’s important to monitor the entire kākāpō population.
Sky Ranger flyovers
Sky Ranger is a kind of data logger that monitors from afar, saving on walking and staff time. It’s used by conservation efforts all over New Zealand.
A datalogger is put in a small plane that then flies a grid pattern over a kākāpō island. The data logger scans all the transmitter channels and records any it detects. It can even record some of the information given out by the transmitters.
We’re trialling GPS trackers to learn more about kākāpō, such as where they prefer to live, what trees they use, what they need to feed their chicks and how often they interact with other kākāpō.