Indicator: Native species
What the results tell us for the ACT
The abundance of native species and conservation of species diversity are both considered to be reasonably good in the ACT because of the large proportion of the ACT protected within reserves. However, there is no comprehensive data base or long-term monitoring to support this view objectively. Overall, with the exception of birds and fish, data on species diversity are limited.
Assessments of vegetation communities and analyses of vegetation clearing between pre-1750 and the present indicate that a number of communities within the ACT have become moderately or highly dysfunctional and in total 46% of the area of the ACT has been changed or modified since human settlement (for an explanation of 'functional' see ecosystem diversity). These changes inevitably will have affected and may continue to affect the abundance and diversity of native species within the ACT. The impacts of past clearing and habitat disturbance on woodland birds are discussed below under Birds.
A detailed list of native plants species found in the ACT is given in Table 1.
Very little is known of the ACT's invertebrate animals, partly because of a lack of research and partly because of the potential number and diversity of the organisms to be studied. Insects are probably the best known of the invertebrate classes. More than 200 species are known from ACT records in the Australian National Insect Collection Specimen Database. These are mainly butterflies, mantids, beetles, flies, moths, dragonflies and termites.
While there is very limited information on invertebrates in general, it is known that the abundance of two insect species, the Golden Sun Moth Synemon plana, and the Perunga Grasshopper Perunga ochracea has been affected by the clearing and modification of the grassy and grassy woodland ecosystems within the ACT. The Golden Sun Moth is declared an endangered species in the ACT and the Perunga Grasshopper has been declared vulnerable. Other species are considered to be of sufficient concern for known locations to be mapped, with a view to building up more data on abundance/vulnerability. One such species is Keys Matchstick Grasshopper Keyacris scurra.
The ACT also provides shelter or a staging site for the migratory Bogong Moth Agrotis infusa between October and November each year. One of the important shelter sites for this species is within the Tidbinbilla Nature Reserve (Environment ACT, September 1999).
There are some data on the ACT distribution and abundance of vertebrates - fish, amphibians, reptiles, birds and mammals. Data on birds are collected by members of the Canberra Ornithological group and can be considered very reliable. Data on other (non-avian) vertebrates are generally insufficiently detailed to identify anymore than very coarse changes in the abundance or distribution of individual species that may have occurred since the commencement of State of the Environment reporting in the ACT in 1994.
Fish in the ACT
There are eleven species of native fish from eight families, which have been recorded from the Canberra region. Some of these fish are not considered native to the Region but have been translocated from adjacent areas or are rare vagrants. Two of these fish species (Murray Cod and Golden Perch) form the basis of important recreational fisheries. Also present in the Region are five species of freshwater crayfish (Lintermans 2000). A list of fish species and their known distribution within the ACT is provided in Table 2.
Amphibians in the ACT
At least 15 frog species currently occur in the ACT (Table 3), with a further two known only from earlier records. The reserve system, including Canberra's parks, lakes, streams and ponds, host most of the ACT's amphibian population. Farm dams in rural areas also provide suitable breeding habitat for many of the amphibian species in the ACT.
Reptiles in the ACT
Over fifty reptile species are presently found in the ACT (Table 4). Twelve of these species have been sighted and recorded in the Tidbinbilla Nature Reserve. Two reptile species, the Striped Legless Lizard Delma impar and the Earless Dragon Tympanocryptis lineata pinguicolla, have populations which are known to be under threat. The Striped Legless Lizard is declared as vulnerable in the ACT and there are only four known disjunct populations occurring in the Territory. These populations occur in Gungahlin, Yarramundi Reach, Majura Valley and the Jerrabomberra Valley. The Earless Dragon, is declared endangered in the ACT. In the ACT, the species only occurs at two sites—the Majura and Jerrabomberra valleys.
Birds of the ACT
More than 200 bird species have been sighted in and around Canberra (Canberra Ornithologists Group, 2000). Over 160 of these species have been sighted within Tidbinbilla Nature Reserve and Namadgi National Park (Environment ACT, September 1999). Data on the abundance and distribution of birds are considered reliable in the ACT, with the data being collected and provided by the Canberra Ornithologists Group. Table 5a identifies and categorises 290 bird species which are found within the ACT, the list includes native and exotic species.
Whilst the ACT is recognised for its diverse and fairly abundant bird populations, some concern was expressed by ornithologists during the reporting period over the survival of woodland bird species. Woodland birds have been severely affected by fragmentation of woodlands and the reduction in the area and size of woodlands, and predation. Predators include cats, foxes, dogs, and other birds, like Pied Currawongs and Noisy Miners.
Concern over the survival of woodland birds extends beyond the ACT into the Region and NSW. Barry Traill (2000) has stated that as 'a result of past clearing we are now in the midst of a major wave of extinctions in woodland birds.' Birds are one of the species most adversely affected by clearing, and there is often a significant lag time between clearing and the effect, ie decline in bird population, taking place.
A list of woodland birds, which are considered to have declining abundance and populations within the ACT and Region, is provided in Table 5b. It is not surprising that three of the vegetation communities that have undergone the greatest level of clearing in the ACT, since European settlement are woodland ecosystems (see ecosystem diversity).
Mammals in the ACT
Some 47 native mammal species have been recorded within the ACT (Table 6). Thirty four of these species have been recorded in Tidbinbilla Nature Reserve(Environment ACT, September 1999). The habitats of most of the ACT's mammal species have probably been fairly well protected within the current major conservation areas (particularly in Tidbinbilla Nature Reserve, Namadgi National Park, Canberra Nature Park and the Murrumbidgee River Corridor). Adopted management techniques, such as the construction of fox proof enclosures within Tidbinbilla Nature Reserve, has allowed populations of a number of native species, such as Koalas and Brush-tailed Rock Wallabies to be sustained. These species were historically present in the ACT, but have virtually been wiped out by exotic predators.
About the data
Information on native species abundance and distribution was sourced predominantly from the 1997 Australian Capital Region State of Environment Report.
Information on birds within the ACT and Region was sourced from the following publications and sources:
- Canberra Ornithologists Group (2000) Birds of Canberra Gardens. Jointly published by Canberra Ornithologists Group and the Department of Urban Services, Canberra
- Environment ACT (1999) Tidbinbilla Nature Reserve Management Plan. Published by Environment ACT, ACT Government, Canberra
- Office of the Commissioner for the Environment (1997) Australian Capital Region State of Environment Report. Published by the Office of the Commissioner for the Environment, ACT Government, Canberra
- Wilson, S. (1999) Birds of the ACT – Two Centuries of Change. Published by the Canberra Ornithologists Group, Canberra
- Barry Traill, from Birds Australia, 2000.
The suggestions and preliminary 'condition' data for the woodland bird species that are under threat was provided by Bruce Lindenmayer, Member, Canberra Ornithologists Group and Conservation Council of The South-East Region and Canberra, Inc.
Data on native fish species were sourced from the 1997 Australian Capital Region State of Environment Report and Mark Lintermans' publication, The Status of Fish in the Australian Capital Territory : A Review of Current Knowledge and Management Requirements, Technical Report No. 15 (March 2000) Published by Wildlife Research & Monitoring, Environment ACT, Urban Services, Canberra.
Data on the number of species sighted within Tidbinbilla Nature Reserve were sourced from Environment ACT (September 1999) Tidbinbilla Nature Reserve Management Plan. Published by Environment ACT, Department of Urban Services, Canberra.
Description: What does 'native species' measure?
Which data are collected?
- abundance of all known species (including condition of selected species and composition at selected sites) of animals, plants and micro-organisms in each biogeographic subregion
Why do we report this indicator?
Changes in patterns of the number of species of living organisms and their relative abundance in a given area can occur naturally - either seasonally or after significant events such as fire or storms. However, a significant loss of native species from an area is generally a clear indicator of major ecosystem disturbance such as habitat loss or predation/competition from introduced species.
Because it can be difficult to identify all species in an area, and even more difficult to monitor their populations, a few (selected) species are generally identified. A significant decline in the abundance and condition of these few species, if carefully chosen, can be indicative of general trends for native species in the area in general.
The species usually selected for closer monitoring are vertebrates. For both aquatic and terrestrial ecosystems, the abundance and distribution of vertebrates provides an indication of the health of our environment, because this reflects the quality of their habitat, including overall water quality. Some species are more sensitive to changes in their environment than others, and not all species are naturally found everywhere in large numbers. For these reasons only a few of the more sensitive, and well-studied, species are used for this indicator in the State of the Environment report.