Justification of Red List Category
This species has been extirpated from the largest island in its historic range by introduced mammalian predators, to which it is highly susceptible. Declines have ceased as mammalian predators are absent from the remaining subantarctic islands where it occurs, and it is relatively secure within this small range. Due to the restricted number of locations and the plausible threat of introduced predators driving the species to Endangered?or?Vulnerable?in?a very short time, the species is classified as Near Threatened.
Encounter rates on Adams Island were more than three times higher than in similar habitat on Antipodes Island, where snipe coexisted with mice until mice were eradicated in 2016 (Miskelly 2020). Adams Island (10,119 ha) is likely to hold tens of thousands of birds, based on recorded densities of at least 4 birds/ha on other islands, while the colonising population on Campbell is likely to number in the hundreds and be increasing. The total area occupied by the species is about 11,540 ha in the Auckland Islands, 2,060 ha in the Antipodes Islands, and about 11,000 ha on Campbell Island (Miskelly 2020). Snipe have been reported during 67–100% of visits from 1988-2018 to Rose and Enderby, and from 1972-2018 to Adams, Disappointment and Ewing Islands (Miskelly et al. 2020), indicating that it is common within its range. A preliminary estimate places the total population in the band 20,000-49,999 mature individuals which remains applicable given that the population is thought to be stable overall, but the true figure may be higher.
Overall, the population is thought to be stable due to the absence of predators in the current range. Despite historic declines, C. a. aucklandica is thought to have remained stable over the last three generations (Robertson et al. 2013, 2017, 2021). On Enderby Island, the frequency sightings significantly increased during 1992–2018 after the eradication of cattle, mice and rabbits (French et al. 2020). Since the eradication of rats from Campbell Island in 2001, the population of C. a. perseverance has recovered and is still thought to be increasing (Robertson et al. 2021). C. a. meinertzhagenae has increased following the eradication of mice from the Antipodes island in 2016 and is also believed to be stable, the population now reaching a higher equilibrium (Graeme Elliott, DOC, pers. obs.).
C. aucklandica is endemic to New Zealand, where C. a. aucklandica is found on the Auckland Islands (Adams, Disappointment, Enderby, Ewing, Rose and Ocean Islands), C. a. meinertzhagenae on the Antipodes Islands (Antipode, Bollons, Archway, Inner Windward and Leeward Islands) and C. a. peserverance on Campbell Island (Campbell and Jacquemart Islands). The species does not occur on the main Auckland Island due to the presence of mammalian predators. C. a. perseverance was not known to exist before a chance discovery on Jacquemart Island in 1997, but has since recolonised the main Campbell Island from Jacquemart Island following the eradication of Norway rats in 2001, and is now rapidly spreading over the 11,290 ha island (Miskelly 2020).
The species favours areas of dense ground cover including tussock grasslands, herbfields, fern, shrubland and low forest where it feeds on a wide variety of invertebrates (Miskelly 2020). It nests on the ground (hence its vulnerability to introduced mammals), laying a clutch of two eggs between July and March (Miskelly et al. 2006, 2020).
Snipe were extirpated from the main Auckland Island by cats Felis catus and pigs Sus domesticus, and from Campbell Island by Norway Rats Rattus exulans (Miskelly 2000; Miskelly et al. 2020). Rats and cats also caused the extinction of two closely related species, C. iredalei and C. barrierensis, from mainland New Zealand and adjacent islands (Higgins and Davies 1996). Were any of these non-native species to be accidentally introduced once more, they could cause rapid population declines in this species.
Conservation Actions Underway
Mice were eradicated from Antipodes Island in 2016. The Campbell Islands population is expanding following the eradication of rats from the main island in 2001. Eradications have also taken place on Enderby and Rose Islands.
Conservation Actions Proposed
The New Zealand Department of Conservation is investigating the feasibility of eradicating pigs, cats and mice from 45,889 ha Auckland Island, which would remove introduced mammals from the entire species' range. Monitor island populations opportunistically. Consider reintroductions to predator-free islands off the New Zealand mainland if appropriate.
23 cm. Small, plump variegated brown wader. Bill brown and slightly drooping, 5 cm; top of head striped black and brown/reddish brown; rest of body mottled black and brown/reddish brown; female larger than male. Similar spp. No other Coenocorypha occurs within the range of C. aucklandica, but it is distinct from C. hugeli by virtue of its longer bill, unbarred mid-belly and more richly coloured upperparts. C. pusilla is much smaller. Voice Males have a territorial loud call consisting of a series of vibrant monosyllabic notes and also produce a non-vocal nocturnal display noise likened to the sound of a passing jet or a chain being lowered onto a boat.
Text account compilers
Benstead, P., Bird, J., Khwaja, N., McClelland, P.J., Miskelly, C., Symes, A., Taylor, J. & Clark, J.
BirdLife International (2023) Species factsheet: Coenocorypha aucklandica. Downloaded from http://datazone.birdlife.org/species/factsheet/auckland-snipe-coenocorypha-aucklandica on 06/06/2023. Recommended citation for factsheets for more than one species: BirdLife International (2023) IUCN Red List for birds. Downloaded from http://datazone.birdlife.org on 06/06/2023.