Source: Raw Shorty

9. Biodiversity


9.2 ACT trends

This section looks at trends for the following biodiversity topics:

What are the main biodiversity findings from the 2023 ACT State of the Environment Report? Watch the video and see the infographic below to find out.

Biodiversity in the ACT

The ACT’s ecosystems and urban environment are home to many flora (plants) and fauna (animals) species – and the number of known species in the ACT is growing as the community and scientists discover more and more! Records from Canberra Nature Map show that there have been over 2,800 unique fauna species sighted in the ACT. This includes:

  • 2,751 native species – 67 mammals, 298 birds, 14 snakes, 49 lizards, 37 frogs, 2 turtles, 28 fish, 188 spiders and 2068 insects.
  • 64 introduced species – 17 mammals, 33 birds, 2 lizards, 1 frog and 11 fish.

The ACT also has many flora species, including:

  • 2,153 native species – 1,034 vascular plants (such as trees, shrubs and herbs), 286 fungi, 512 lichens, 3 hornworts, 83 liverworts, 207 mosses and 28 slime moulds.
  • 700 introduced species, 79 of which were introduced from elsewhere in Australia.

There are also four plant species that are only native to the ACT. These are the Canberra Spider Orchid, Brindabella Midge Orchid, Ginninderra Peppercress and Tuggeranong Lignum.

Click on the pictures below to see the plant species that are only native to the ACT!

Did you know?

Many highly mobile species like birds also migrate through the ACT and may only be present for breeding, or in response to food and water availability. It’s important to note that the presence of these temporary residents in the ACT can change each year depending on external factors – for example, changes to food availability, loss of habitat or increase in invasive species in other places.

As a result, populations can increase or decrease regardless of the condition of the ACT environment. That is why it is important to protect native species and their habitats wherever they are found.

The Latham Snipe migrates through the ACT. Source: Ryan Colley.

Threatened species

When we measure biodiversity, we mostly focus on threatened species. This is because it’s not possible to accurately measure where all species live and how many there are in the ACT. Not all species occurring in the ACT are known, let alone counted, and not all areas of the ACT can be surveyed and monitored.

So, biodiversity assessments focus on threatened species instead. Threatened species are those that are at risk of becoming endangered due to losses or changes to their habitat or a reduction in their population numbers. A species can be threatened over a large area (e.g. threatened in Australia), or in a specific area (e.g. threatened in the ACT).

Levels of threat

A threatened species is given a conservation status based on the level of threat to its survival. A species can be classed as:

  • Critically endangered: a species facing an extremely high risk of extinction in the wild in the immediate future.
  • Endangered: a species facing a very high risk of extinction in the wild in the near future.
  • Vulnerable: a species facing a high risk of extinction in the wild in the medium-term future.
  • Regionally conservation dependent: a species dependent on management.

Many species need our help. There are 58 fauna and flora species listed as threatened in the ACT. This includes:

  • 8 critically endangered species
  • 21 endangered species
  • 28 vulnerable species
  • 1 regionally conservation dependent species (the Eastern Bettong)

A full list of the ACT’s threatened species and the main impacts on them can be found HERE.

This graph shows the number of species listed as threatened in the ACT. Birds, mammals and flora account for most of the threatened species.

Data sourced from: Environment, Planning and Sustainable Development Directorate.

The ACT also has three threatened ecological communities, these are:

  • the critically endangered Natural Temperate Grassland and Yellow Box / Red Gum Grassy Woodland ecological communities, and
  • the endangered High Country Bogs and Associated Fens ecological community.

Our native species are under increasing pressure from climate change, invasive species, fire and habitat loss. Between 2019 and 2023, six new species were added to the ACT’s Threatened Species list. These are:

  • Gang-gang Cockatoo (Callocephalon fimbriatum) listed as Endangered
  • Key’s Matchstick Grasshopper (Keyacris scurra) listed as Endangered
  • Mountain Skink (Liopholis montana) listed as Endangered
  • White-throated Needletail (Hirundapus caudacutus) listed as Vulnerable
  • Yellow-bellied Glider (South-eastern) (Petaurus australis australis) listed as Vulnerable, and
  • Pilotbird (Pycnoptilus floccosus) listed as Vulnerable

In addition, three species were given a higher threat status between 2019 and 2023. These are:

  • Canberra Grassland Earless Dragon (Tympanocryptis lineata) changed from Endangered to Critically Endangered
  • Southern Greater Glider (Petauroides volans) and Koala (Phascolarctos cinereus) changed from Vulnerable to Endangered.

Only one species was given a lower threat status. The Golden Sun Moth (Synemon plana) changed from Endangered to Vulnerable.

A full list of the ACT’s threatened species and the main impacts on them can be found HERE.

Click on the pictures below to see the six native animals added to the ACT’s Threatened Species list between 2019 and 2023.

Did you know?

The most common threats to biodiversity in the ACT are:

  • climate change
  • more frequent and intense bushfires
  • habitat fragmentation
  • land clearing for new housing or agriculture
  • invasive plants and animals
  • reduced river flows
  • vegetation/plant loss
  • poor water quality

Invasive species

Invasive species put pressure on native plants and animals, and need to be carefully managed to protect native biodiversity. The ACT’s native species are significantly impacted by feral pigs, deer, foxes, rabbits, horses, cats, and wild dogs, as well as a range of invasive plants. Invasive fish species such as carp also impact on our aquatic biodiversity. These introduced species can reduce biodiversity by eating native animals, competing with them for food and habitat, spreading disease and parasites, and displacing native plants which provide habitat and food.

Rabbits are the most damaging invasive species in the ACT. They dig up native vegetation and cause erosion, introducing weeds and making it difficult for native plants to grow. Rabbits can very quickly turn a healthy environment full of many different types of native plants and animals into a paddock containing just one type of weed. Rabbits breed quickly, so their numbers can rise rapidly. As rabbits are a food source for foxes, more rabbits lead to more foxes, which then prey on small native species. Foxes have even caused local extinctions, such as those of the Bettong which are small, nocturnal marsupials.

Horses, deer, cattle and other hooved farm animals can damage the environment when free to roam in native bush, particularly in sensitive high country areas. Unlike any native Australian animal, these animals have hard hoofs that erode the ground, removing grasses and disrupting soil. Eroded soil can then wash into local waterways. Hard hoofs can also destroy fragile alpine bogs, which are important for regulating water flow from alpine regions.

Feral pigs damage native ecosystems, impacting on our native biodiversity and ecosystem health.
Source: Environment, Planning and Sustainable Development Directorate

Feral pigs, wild dogs and Indian Myna birds are also problematic invasive species. The ACT has recognised this and there are programs, such as baiting and trapping, to control their numbers.

Native animals can also threaten biodiversity. When in high numbers, kangaroos are considered pests in some areas of the ACT, particularly for sensitive and threatened grasslands. Too many kangaroos can lead to a loss of grasses and other plants which don’t have a chance to recover from the continual grazing (or eating) by kangaroos. The loss of plants leads to erosion, making it even harder for native species to grow. Weeds, often well suited to harsh growing conditions, can then take over, damaging native ecosystems. These changes can lead to a loss of native species which lose their habitat and food sources. Some threated species that can be impacted by overabundant kangaroos include the Canberra Grassland Earless Dragon, Striped Legless Lizard, Pink-tailed Worm Lizard, Perunga Grasshopper, Hooded Robin, and Brown Treecreeper, which all rely on an intact grassy layer for survival.

The Canberra Grassland Earless Dragon can be impacted by overabundant kangaroos. Source: Ryan Colley.

Did you know?

Cats may be cute pets, but they are extremely harmful to native biodiversity. Cats hunt native birds, reptiles and small mammals. Collectively, roaming pet cats kill 546 million animals per year in Australia!

In the ACT, we have cat containment laws. Containment means keeping your cat on your property at all times – either inside your house or apartment, in an enclosed area outside, in a cat crate, or on a leash. These laws apply to all cats born after 1 July 2022. Some suburbs in Canberra have been declared cat containment areas, which means all cats there must be contained regardless of age. Find out if you live in a cat containment area HERE.

Cats kill large numbers of native animals. Source: Akira B.

Caring for land, supporting our species

Caring for our land is critical to protecting and maintaining biodiversity. Conservation areas are important because they provide areas for species to live, move and breed with less disturbance from humans.

Did you know?

Over 60% of the ACT is protected in conservation areas! This is a much higher proportion than any other jurisdiction in Australia. Namadgi National Park and the Bimberi Wilderness Area account for over 75% of the conservation area. Nature reserves (including Canberra Nature Park) account for around 14% of the conservation area.

This map shows the conservation areas in the ACT. Over 60% of the ACT is protected in conservation areas.

Data sourced from: Environment, Planning and Sustainable Development Directorate.

Despite our wide network of conservation areas, many threatened species and a large proportion of threatened ecological communities fall outside reserved land. For example, over 60% of the ACT’s Southern Tableland Grassy Woodlands are outside reserves. The least protected ecosystems in the ACT are the woodland, grassland and open forest communities. It is important to protect more of these ecosystems in order to support the species that rely on them.

Offsets

Environmental offsets are areas of land that have been set aside to make up for the ecological damage caused by developments (such as new housing). The idea is that when land is cleared in one area to build a new suburb, another area with similar environmental values is protected and improved instead. The aim of environmental offsets is no net-loss of biodiversity – meaning that the biodiversity that is lost in one area is gained back in another.

In 2023, there were 23 environmental offsets areas covering 1,865 hectares in the ACT. Nearly half of this area is protected in nature reserves. However, it is very difficult to determine if environmental offsets actually work. It is challenging to measure whether biodiversity has improved in the environmental offset area, or even been maintained. In some cases, environmental offsets do not replace the biodiversity lost by the development.

Because of this, it is important we prioritise protecting existing environments, rather than allowing developments to be built that destroy habitats and require environmental offsets (see Canberra’s growing urban area).

This map shows the location of environmental offset areas in the ACT in 2023. There are currently 23 environmental offset areas covering 1,865 hectares in the ACT. These have been established to compensate for habitat loss from urban development.

Data sourced from: ACT Parks and Conservation Service.

Revegetation

Revegetating cleared areas is an important way to care for our land and support biodiversity. It not only restores habitat, but creates corridors for species to move between areas of habitat. Between 2015 and 2023, there were over 130,000 trees and shrubs, and 200 kilograms of native seeds, planted in the ACT’s nature reserves.

While growing new trees is important in areas that have been cleared, it is also important to save old trees because these provide habitat such as hollows where birds and possums can live. Large, old trees can be damaged by disease, insects and drought, or be cut down to make way for new housing developments.

Planting habitat shrubs for small birds with Jarramlee Park Landcare Group. Source: Ginninderra Catchment Group.