EN
New Zealand Rockwren Xenicus gilviventris



Taxonomy

Taxonomic source(s)
del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A., Fishpool, L.D.C., Boesman, P. and Kirwan, G.M. 2016. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 2: Passerines. Lynx Edicions and BirdLife International, Barcelona, Spain and Cambridge, UK.
Turbott, E.G. 1990. Checklist of the Birds of New Zealand. Ornithological Society of New Zealand, Wellington.

IUCN Red List criteria met and history
Red List criteria met
Critically Endangered Endangered Vulnerable
- A2ce+3ce+4ce A2ce+3ce+4ce

Red List history
Year Category Criteria
2022 Endangered A2ce+3ce+4ce
2016 Endangered A3ce+4ce
2012 Vulnerable C1+2a(i)
2008 Vulnerable C1; C2a(i)
2005 Vulnerable
2004 Near Threatened
2000 Lower Risk/Near Threatened
1994 Lower Risk/Near Threatened
1988 Lower Risk/Least Concern
Species attributes

Migratory status not a migrant Forest dependency does not normally occur in forest
Land-mass type Average mass -
Range

Estimate Data quality
Extent of Occurrence (breeding/resident) 79,900 km2 medium
Severely fragmented? yes -
Population
Estimate Data quality Derivation Year of estimate
Population size 1250-6000, 5000 mature individuals medium suspected 2020
Population trend decreasing medium inferred 2017-2027
Rate of change over the past 10 years/3 generations (longer of the two periods) 50-70% - - -
Rate of change over the future 10 years/3 generations (longer of the two periods) 50-70% - - -
Rate of change over the past & future 10 years/3 generations (longer of the two periods) 50-70% - - -
Generation length 2.66 years - - -
Number of subpopulations 3 - - -
Percentage of mature individuals in largest subpopulation 1-89% - - -

Population justification: The population was previously estimated to number 2,500-9,999 mature individuals (R. Hitchmough in litt. 2005). Robertson et al. (2021), assessing the species according to criteria elucidated in Townsend et al. (2008), placed the southern subspecies in the band 1,000-5,000 mature individuals and the northern subspecies in the band 250-1,000. The total population is best estimated to number c.5,000 mature individuals (Gill and Sharpe 2020).

Trend justification: Predation by stoats causes extremely high rates of nest failure and are thought to be causing significant declines (Little et al. 2017). Sightings in Mount Cook National Park have declined markedly since the 1980s and early 1990s (Michelsen-Heath and Gaze 2007). In 2005, at 20% of known localities there were no sightings in the past 20 years (P. Gaze per R. Hitchmough in litt. 2005). Its range continues to decline (Michelsen-Heath and Gaze 2007) and a 40% decline in abundance over a 20-year period occurred in the Murchison mountains (Willians 2007). Since 2012, the species is suspected to have been undergoing steeper declines equivalent to 50-70% in ten years and this is thought to be continuing (Robertson et al. 2013, 2017, 2021).


Country/territory distribution
Country/Territory Presence Origin Resident Breeding visitor Non-breeding visitor Passage migrant
New Zealand extant native yes

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Grassland Subtropical/Tropical High Altitude suitable resident
Rocky areas (eg. inland cliffs, mountain peaks) suitable resident
Shrubland Subtropical/Tropical High Altitude major resident
Shrubland Temperate major resident
Wetlands (inland) Permanent Rivers/Streams/Creeks (includes waterfalls) suitable resident
Altitude 900 - 2400 m Occasional altitudinal limits  

Threats & impact
Threat (level 1) Threat (level 2) Impact and Stresses
Climate change & severe weather Other impacts Timing Scope Severity Impact
Future Unknown Unknown Unknown
Stresses
Species mortality
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Mus musculus Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Stresses
Reduced reproductive success
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Mustela erminea Timing Scope Severity Impact
Ongoing Majority (50-90%) Rapid Declines Medium Impact: 7
Stresses
Species mortality

Recommended citation
BirdLife International (2024) Species factsheet: New Zealand Rockwren Xenicus gilviventris. Downloaded from https://datazone.birdlife.org/species/factsheet/new-zealand-rockwren-xenicus-gilviventris on 22/11/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from https://datazone.birdlife.org/species/search on 22/11/2024.