Takahē conservation involves collaborative research, with experts in fields such as genetics, predator control, and bird health.
Some of the research projects currently being undertaken include:
Transmitter harness trials
To help monitor takahē in the Murchison Mountains and on some island and mainland sites takahē are often fitted with transmitters. Most of these transmitters are fitted to takahē using a backpack harness which fits over their wings. In recent years backpack harnesses have been associated with bone remodelling and soft tissue injuries in takahē. These effects increase with the length of time that the harness is worn. As a result, current transmitters are removed after three years, and we’re searching for an alternative transmitter attachment method.
Two alternative designs are currently being trialled, to assess their impact on takahē health, survival and reproduction. A further study to assess the energetic cost of transmitter wear is planned.
Leg Mount transmitters, which are commonly used on kiwi and, as suggested by their name, are mounted high on the leg of takahē. We have trialled these on six birds at the Burwood Takahē Centre.
Flight harness transmitters are another option being trialled. Similar harnesses are used on whio, weka, pateke, kea and kaka. Flight harness transmitters sit on the back of takahē like the current backpack transmitters but are fitted around under the chest taking pressure off the patagium (top part of the wing where it joins the main body of the bird). The flight harness transmitter has a weak link on the chest section designed to break if the transmitter gets caught up in anything. We started by working with takahē (Kawa and Tumbles) at the Te Anau Bird Sanctuary to modify the design used for whio/blue duck. We then trialled them on birds at Burwood and with good results thus far have extended the trial to takahē at a number of secure sites.
Bait Repellent Trials
One of the biggest threats to takahē survival is introduced predators such as stoats. An extensive network of rodent and mustelid traps current protects takahē in their biggest mainland site in the Murchison Mountains. However, the ability to use aerial toxins in takahē habitat is necessary for continued protection of this and future sites. This is currently not possible due to the risk of poisoning takahē. The Takahē Recovery Programme is trialling repellents that will deter takahē from eating toxic baits.
There are sex biases as some takahē sites, with a variation between female-biased and male-biased populations. The reasons for these sex skews are not known, so a research programme is attempting to determine whether factors such as supplementary feeding or parent condition are responsible.
Takahē can carry high loads of the parasite coccidia, usually found in the gut. The species of coccidian that infect takahē, and the range of loads, is unknown. A veterinary study is determining the impacts of coccidia on takahē, to develop a screening protocol and treatments.
Pukeko and Australasian harriers are known to prey on takahē, but their impacts have not been measured. This study will determine the effect of these native predators on takahē populations.
The takahē population in the Murchison Mountains is vulnerable to stoat predation following beech mast-driven rodent plagues. Yet the impact of stoats on this population is unclear, and there is limited ability to predict these stoat plagues. This research will lead to a clearer understanding of rodent-stoat-takahē population dynamics. A separate study is providing important information on the effectiveness of the Murchison Mountains trap network.