Justification of Red List Category
The population has been estimated at 3000-4000 pairs, equivalent to 6,000-8,000 mature individuals and c.9,000-12,000 individuals in total. Following the eradication of rats and mice from the island in 2015, it is possible that the population has increased due to an increase in range size, however surveys are needed to confirm this (T. Martin in litt. 2020).
The population is suspected to be stable in the absence of evidence for any declines or substantial threats.
Anthus antarcticus is endemic to the sub-Antarctic island of South Georgia (Georgia del Sur), with a total population estimated as 3,000-4,000 pairs (McIntosh & Walton 2000). Following the eradication of brown rats Rattus norvegicus and house mice Mus musculus (Martin & Richardson 2017), the population has likely increased. Subsequent to the eradication of invasive rodents between 2011 and 2015, this species now breeds and occurs year-round in all vegetated parts of the main island and smaller offshore islands (T. Martin in litt. 2020).
It breeds in low altitude tussock grassland, wintering mainly on ice-free shorelines (Prince & Croxall 1983). It feeds on insects in tussock habitat, and insects and crustaceans along tidelines (J. P. Croxall in litt. 2000). In typical habitat it is common and productive, but winter survival of juveniles is low. It has almost no natural predators, remains of birds very occasionally turning up at middens of Brown Skua Catharacta lonnbergi (J. P. Croxall in litt. 2000).
Following the eradication of rats and mice from the island (Martin & Richardson 2017), there are no known threats to this species.
Conservation Actions Underway
The eradication of rats and mice from the island was completed c.2015 (Martin & Richardson 2017).
Text account compilers
Croxall, J., O'Brien, A., Stattersfield, A. & Taylor, J.
BirdLife International (2022) Species factsheet: Anthus antarcticus. Downloaded from http://www.birdlife.org on 27/06/2022. Recommended citation for factsheets for more than one species: BirdLife International (2022) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 27/06/2022.