Ship rats have been introduced to the Lake Rotopiko Waikato wetland in an endeavour to combat the hundreds of thousands of birds that live there.
The outcome is far from certain of theist under 50 ship rats released the Rotopiko sanctuary with its predator-proof fence. Proponents say the droppings ofsparrows, finches and starlings are threatening the lake’s water quality.
Noise via noise cannons and also fog misters have been tried but to no effect. The plans for Lake Rotopiko is to be a national wetlands visitor centre. National Wetland Trust executive officer Karen Denyer does not expect instant results. It’s uncertain that the rats will succeed in their mission. Initially it was thought releasing only male rats would be best but that was discarded that that might spur them to escape in search of females.
Rats breed every two to three months and can produce a litter of eight to 12 offspring each time. At just six weeks of age a young female can become pregnant. Rats are super prolific breeders and numbers build up quickly with abundant food until predator-prey relationships stabilise.