Pests and threats

Wellington's native biodiversity is up against a lot – further habitat loss, pest animals and plants.

Biodiversity is at risk

Biodiversity is in decline globally, and the rate of loss is getting faster. In New Zealand, one-third of our birds are now extinct and three-quarters of the remaining species are threatened. There has also been a decrease in lizards in the last five years.

The main concerns for Wellington's biodiversity are further habitat loss as the city continues to develop and the continued affects of introduced pest species on native flora, fauna, and their habitats.

By understanding what we've lost and how, we can focus on how to restore and protect it for the future.

Human activity has caused habitat loss

With the settlement of Wellington, the use of the land had major impacts on the natural vegetation. Forests were burned or chopped down for houses and farms. Native vegetation was paved over and streams were piped to build the city above. Lyall Bay was mined for sand and Owhiro Quarry for rock.

Only 5% of Wellington's original forest remains in valleys that were spared or too difficult to access. Wellington's wetlands and dune systems have been almost entirely wiped out.

The destruction of large ecosystems into smaller, disconnected parts has isolated native animals and plant populations, making them more vulnerable.

See the contrast: 

Wellington's Original Habitat Cover (677KB PDF) 

Wellington's Current Habitat Cover (562KB PDF)

Introduced pests threaten native flora and fauna


Pest plants (weeds) threaten and change our natural environment. They often grow quickly, smother and kill native plants, and spread their seeds widely.

Weeds alter habitats – changing the plants that grow there, reducing food sources and breeding sites for our native wildlife, and further reducing species and habitats.

75% of New Zealand’s problem weeds have 'jumped the fence' from people’s gardens. There are now more introduced plant species growing wild in New Zealand than there are native plant species, and the number is growing.

Weed issues in Wellington include:

  • garden dumping – in parks, streams, and on beaches
  • climbing weeds – such as old man’s beard, which strangle and smother native plants
  • woody weeds – such as sycamore, which out-compete native trees
  • ground cover weeds – such as tradescantia, which stop native plants from regenerating
  • new, emerging weeds that continue to appear and establish themselves

Find out what we are doing to manage these issues through our restoration projects.

What we do for the environment - Weed Control

Pest animals

Pest animals have devastating effects on native Wellington plants and animals. These cunning creatures easily adapt to New Zealand habitats where they compete for food by feeding on plants or their seeds or seedlings.

They also impact native wildlife directly as they prey on native birds, lizards, and insects that are key to our forests and distributing seeds throughout different habitats.

The more notorious culprits include:

  • rats and mice
  • stoats and weasels
  • possums
  • hedgehogs
  • feral cats

Other less obvious species include:

  • feral goats
  • feral pigs
  • feral rabbits
  • feral deer

These less obvious pests damage ecosystems on a large scale by feeding on young, regenerating native plants and cause erosion through trampling, digging, and burrowing.

We run integrated pest management programmes year-round in our parks and reserves.

What we do for the environment – Pest and predator control

A combined effort means hope for biodiversity

In Wellington, there is a combined effort between the community, the Council, and partner organisations to protect and restore our biodiversity. We are committed to restoring what we once had, and making sure it continues to flourish in the future.

Through trapping, weeding, planting, and other restoration work, the number of pests and predators are decreasing while native plants and animals are increasing in Wellington.

You can help

With weeds:

With pest animals:

With the community: