|
|
Gallirallus australis
– Vulnerable
Taxonomy
|
Kingdom:
|
ANIMALIA
|
|
Phylum:
|
CHORDATA
|
|
Class:
|
AVES
|
|
Order:
|
GRUIFORMES
|
|
Family:
|
RALLIDAE
|
|
Scientific Name:
|
Gallirallus australis
|
|
Species Authority:
|
(Sparrman, 1786)
|
|
Common Name/s:
|
|
Assessment Information
|
Red List Category & Criteria:
|
VU A3bce ver 3.1 (2001)
|
|
Year Assessed:
|
2006
|
|
Assessor/s:
|
BirdLife International
|
|
Evaluator/s:
|
Butchart, S. & Pilgrim, J. (BirdLife International Red List Authority)
|
|
Justification:
|
This species's future hold on its mainland range is precarious, with a complex array of threats causing rapid declines resulting in local extinctions. Its situation may be unique in that the species remains numerous on a very large number of islands. Whilst population declines have slowed to an extent over the last 10 years, the species is projected to undergo rapid population declines over the next decade based on extrapolation from historic trends, the absence of any change in the threatening processes, and the impact of climate change. It is therefore considered Vulnerable.
|
|
History:
|
| 1988 | - | Lower Risk/least concern (BirdLife International 2004) |
| 1994 | - | Lower Risk/near threatened (Collar, Crosby and Stattersfield 1994) |
| 2000 | - | Vulnerable (BirdLife International 2000) |
| 2004 | - | Vulnerable (BirdLife International 2004) |
| 2005 | - | Vulnerable (BirdLife International 2005) |
|
Geographic Range
|
Range Description:
|
Gallirallus australis is endemic to New Zealand. Subspecies greyi is mostly restricted to the east coast of the North Island, and has undergone significant declines since the early 1980s to c.4,000 birds3,4,6. Three mainland populations remain, including an introduced population at Russell (100 birds)9. More than 100 releases to former mainland habitats have been attempted, but most have been largely unsuccessful3 due to high predation. Nominate australis remains locally common in north and west South Island3,5, but numbers fluctuate dramatically, even in large populations3. In north-west Nelson, numbers plummeted by c.95%4, in north Westland, counts indicate declines of over 90% in c.20 years1, but in Fiordland, its numbers are currently increasing10. Subspecies hectori is now extinct in its natural range, but was introduced to Chatham and Pitt Islands where it may number between 38,000-58,000 birds4, and survives a take of 5,000 birds annually3. Subspecies scotti became extinct on Stewart Island in the 1990s6, but introduced populations survive on surrounding islands5, and may number less than 25,000 birds4. Overall, the four races are present (many as introduced populations) on more than 70, mostly tiny, offshore islands3. Whilst there have been no major declines in the last ten years, future population crashes are predicted, as climate change is likely to increase the probability of such events occuring10.
|
|
Countries:
|
Native:
New Zealand
|
Population
|
Population Trend:
|
|
Habitat and Ecology
|
Habitat and Ecology:
|
It utilises most habitats, including forests, grasslands, scrub, inland and coastal wetlands and even semi-urban environments. It is omnivorous, taking mostly fruit and invertebrates, but also vertebrates3,7. Birds breed in their first year and eggs are laid year-round8.
|
|
System:
|
Freshwater
|
Threats
|
Threats:
|
Rapid declines are due to a combination of habitat clearance and degradation, road-kills, a wide range of introduced mammalian predators and competitors, combinations of drought and flood years, poison baits used for possum and rabbit control, and disease2,3,5,6. Birds have been eradicated from several islands due to possible risks to other native biota, and removal from Pitt and other islands is a future possibility3.
|
Conservation Actions
|
Conservation Actions:
|
Conservation measures underway:
Further island translocations are planned3. Surveys of distribution and density are presently being completed in parts of the mainland range considered to be strongholds4,6.
Conservation measures proposed:
Clarify population distribution and status of all taxa. Conduct research on impacts and management of threats3. Implement monitoring programmes in appropriate sites for all taxa. Identify the most important threats affecting sites and instigate management programmes to address these. Establish further populations to ensure each taxon has at least one large mainland population and three island populations.
|
|
|
