He says domestic cats are less likely to hunt for native birds because they're well fed at home and have a small hunting territory.
He says they may actually be helping keep predator numbers down.
Because domestic cats protect their territory (in this case, the area around their houses), they attack predators such as stoats, weasels, rats and feral cats that might prey on native birds.
In the Red Zone of Christchurch, since all the house cats have moved out, the pests have moved back in.
The pests don't have everything to do with birds numbers.
"Predation has nothing to do with bird increase." Crossland says it actually has more to do with habitat.
Back around the 1980's, there were many wide open spaces, oak trees and very few birds such as the Spotless Crake.
Now, since DOC have been working on creating habitats with dense trees and longer grasses around river banks, there are quite a few native birds being seen.
Crossland says despite human intervention and predators, native bird numbers are on the rise.
