The two departments have been working to find the cause of a mysterious neurological disease that affects up to 10% of kakī chicks before they fledge at 35 days old.
The disease causes inflammation of the brain and other organs, leading to muscle tremors, loss of co-ordination, decreased ability to eat and, in many cases, causes death.
“We’ve gone through and ruled out all the common and known factors that could’ve potentially been causing the disease and now we’re trying something different,” says Kelly Buckle, one of MPI’s Incursion Investigators.
“MPI’s Animal Health Laboratory has the latest in sequencing technology available. Our scientists are using this technology to analyse the DNA of diseased tissue from kakī chicks.”
To obtain suitable samples, tissues were painstakingly collected by DOC Twizel-based kakī ranger Liz Brown and DOC veterinarian Kate McInnes. The samples were shipped in liquid nitrogen to the MPI laboratory to ensure they arrived in pristine condition.
Testing will likely take several months, as MPI scientists analyse millions of DNA sequences extracted from the tissue of diseased chicks.
"The hope is that the data produced may provide evidence of an infectious cause behind the neurological disease, so that we can find the best way to prevent it,” says Kelly Buckle.
Alongside the MPI investigation, DOC is continuing efforts to save these wading birds. This week DOC is to release 79 young kakī into South Canterbury’s Mackenzie Basin as part of their ongoing conservation programme. Isaac Conservation and Wildlife Trust have been supporting the kaki programme since 1992 and 27 of the released birds will come from the trust’s chick-rearing facilities in Christchurch.
“Despite the programme’s high breeding successes in recent years, we’ve struggled to increase the population which sits at around 93 wild birds. Approximately 70 % of the young birds released this week are likely to be taken by predators before reaching adulthood,” says Liz Brown.
“The stilts’ ability to travel great distances and their unique habitat requirements prevents DOC from safeguarding the species in predator-free locations. Currently our best option for their conservation is a combination of high-output captive breeding and pest control.”
A harsh breeding season and limited aviary facilities due to storm damage last year has resulted in fewer kakī reared through the recovery programme this year. DOC has finished repair work on the first of the damaged aviaries which will be ready for use in the upcoming breeding season and plans to boost survival rates using a new release site for 36 of this year’s young kakī.
“As well as this work by MPI and Isaac Conservation and Wildlife Trust, the Department is grateful for significant contributions to kakī recovery from Massey and Canterbury universities, Ngāi Tahu and the local Mackenzie community,” says Liz Brown.
“We’re really hoping that over the next few years we will see this bird finally start on the road to recovery.”