It’s been a few weeks now, since we got news of a rare rowi kiwi, Aroha who had wandered far from her lowland forest home, to a cliff face in the snowy mountains of South Westland. We recently caught up with ranger Iain Graham who led the search and rescue mission, for a bit more of a background to Aroha’s story and an update to hear how she is currently doing.
Iain: Aroha wears a smart transmitter that records the amount of time she spends moving or foraging for food each night. If this transmitter stops moving for over 12 hours, it switches into mortality mode and lets us know she has either dropped her transmitter or died.
In general, a normal healthy kiwi will feed for as long as it is dark each night and a when a kiwi is incubating an egg, it will feed for half that time. When this happens, we are able to determine when a monitored kiwi lays and incubates an egg and the transmitter switches into incubation mode.
The transmitter doesn’t have a gps unit built in, as this technology is far to power hungry to run on a suitably sized battery. The technology used to find the birds is similar to the old analogue locator beacons. A rough position is found each month by a small plane, that collects the signals and data as it flies over the area. The exact position is found by the ranger on the ground with an antenna and receiver.
In May Aroha went wandering from her usual area beside Lake Gault and her rough position was followed by the monthly monitoring flights. She moved out towards Gillespies beach road for a month. The following month her signal was 8km to the east beside lake Mueller and then she was gone! At the beginning of August Aroha’s signal was found after some freestyle searching from the plane. When followed up on the ground it was narrowed down to an area on the slopes of Mt Mitchell and her transmitter was in incubation mode. As she was far too young to be breeding, this suggested she wasn’t moving much. Three weeks later another attempt was made from below, from the sides and from above to get to her. However, vertical rock faces meant it wasn’t going to happen without ropes. Given her lack of movement over the past weeks The LandSAR Alpine Cliff Rescue team were asked if they would like to use it as a training opportunity.
When performing health checks we weigh each bird and compare that weight to its previous three weights. We give it a body-condition score, between one and five, based around the prominence of its ribs and spine. 1 being skin and bone and 5 being very healthy. We also take into account the birds behaviour while handling, ie is it active and feisty or lethargic and drowsy etc.
If during a health check a bird has lost >25% of their body weight, since the last health check, then we intervene by sending them to either Massey Universities Wildbase Animal Hospital or The Wildlife Hospital in Dunedin. Here they are fed on a captive kiwi diet, diagnosed to see if there is an underlying injury or disease that has caused the significant weight loss and subsequently treated if anything is found.
Air New Zealand flies all our taonga species around New Zealand free of charge. This allows us to undertake trans-locations and get these species to veterinary treatment in the shortest time, and with the least stress possible.
When Aroha was found on the ledge she weighed in at 1400g, her weights prior was 1680g, when she was released and weighed 1830g at her three month health check. Her weight loss was 24% so very close to the 25% trigger. Her body condition score was 2 so she didn’t have much reserve left. However, she was still pretty feisty. Pulling a bird for treatment is not a decision that is made lightly as it can obviously be a very stressful experience for a wild bird.
The decision was made to release her back to lake Gault and check on her again in a couple of weeks to see if her weight had increased. Of course Aroha didn’t stay put, and again she disappeared for the next flight. Some more freestyle flying found her again, up to the west of Lake Matheson and we raced in the following day to check on her before she could move to far again.
Aroha has quickly replaced the 400 grams she lost during her mountain adventure. Her quick weight gain suggests she was in fact unable to move from her ledge where she wasn’t getting enough food to sustain her.
She is currently residing up behind lake Matheson approx 5km away from where she was released post rescue. We are looking forward to the next challenge she poses!!