Night trap capture of ferrets cats and harriers in black stilt habitat, Canterbury

Tui had a much easier life before humans came to New Zealand. Their only competitors were birds and native bees although bats, reptiles and invertebrates may also have competed for some foods. Today tui face a number of threats that make it difficult for them to survive, find food and reproduce.

Tui have lost much of the forest habitat where they once lived. Polynesians and Europeans destroyed large areas of forest when they arrived. Tui have had to move into other habitats, such as suburban gardens.

Today the greatest threats to tui are introduced predators such as rats, cats, stoats and possums. These animals eat tui and compete with them for food. Other competitors include wasps and introduced birds like starlings which eat lots of small fruits.

Possum bait station, Pureora Forest.

The reason there are so few tui in Canterbury is because it is a very long way from the foothills across the plains to Banks Peninsula and there is virtually no native forest left on the Plains. On Banks Peninsula tui have declined almost to zero over the last 20 years. The causes of the decline are thought to be loss of habitat through burning of flax and shrublands, competition with possums and introduced birds and predation by stoats, cats, rats and possums.

Because humans are responsible for making life so difficult for tui and other native birds, we also have a responsibility to try to protect our birds from these new threats. If humans did nothing, many of our native birds would eventually become extinct. These birds simply cannot survive now without our help.

Rat emerging from rat tunnel with poison bait, Breaksea Island.

The main way that we can help tui and other native birds is by controlling the introduced predators that we brought to New Zealand. Scientists have developed many clever ways to kill these predators. Mostly they use traps or poisons.  The poisoned baits are placed inside bait stations to keep ground birds like weka and kiwi from being killed. The baits are also dyed green and flavoured with cinnamon to keep birds away. Traps to kill stoats and rats are usually placed inside a tunnel to keep other animals away from them but also because stoats and rats like going into dark holes and burrows.

Stoat trap box containing a Fenn trap baited with an egg, Maud Island.

Someday scientists may develop more permanent ways to eliminate all of these introduced predators from New Zealand forever. It may be possible to develop a virus that only attacks a certain species, or it might be possible to stop females from having babies. At the moment, though, we are a long way from discovering a method like this that is safe and effective. In the meantime, if we want tui and other native birds to survive, our only choice is to keep controlling predators where ever we can.