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Cook Islands Reed-warbler Acrocephalus kerearako
BirdLife is updating this factsheet for the 2016 Red List
Please email us with any relevant information

This species qualifies as Near Threatened because although it is currently considered common where it occurs, it has a moderately small range and as such is capable of becoming threatened in a very short time. It may be declining due to predation by introduced species.

Taxonomic source(s)
Sibley, C. G.; Monroe, B. L. 1990. Distribution and taxonomy of birds of the world. Yale University Press, New Haven, USA.

Distribution and population
Acrocephalus kerearako remains common on the two tiny islands of Mangaia and Miti'aro, Cook Islands (McCormack 1997).

Population justification
The global population size has not been quantified, but the species is described as still common and numerous on both islands in its range (del Hoyo et al. 2006).

Trend justification
There are no data on population size and trends. However, the species may be experiencing a slow decline due to predation by introduced species and habitat loss and fragmentation.

It inhabits a variety of habitats including reeds, gardens and woodland (Pratt et al. 1987).

On Mangaia, there are a variety of introduced species including the aggressive Common Myna Acridotheres tristis (numbering c.9,000 birds), cats and rats (both Pacific rat Rattus exulans and black rat R. rattus), and clearance for agriculture and browsing by goats causes habitat loss and fragmentation (Rowe and Empson 1996).

Conservation Actions Underway
The feasibility of eradicating A. tristis has been evaluated; it is thought possible at the cost of $100,000 and has the support of local people. Conservation Actions Proposed
Carry out a survey to determine population size so that future trends can be revealed. Implement the planned eradication of A. tristis on Mangaia. Train local people in animal husbandry techniques which will minimise negative impacts on the forest. Set aside and protect an area of forest on each island. Investigate the taxonomic status of the populations on the two islands.

del Hoyo, J.; Elliott, A.; Christie, D. 2006. Handbook of the Birds of the World, vol. 11: Old World Flycatchers to Old World Warblers. Lynx Edicions, Barcelona, Spain.

McCormack, G. 1997. Cook Islands: an oceanic oasis. World Birdwatch 19: 13-16.

Pratt, H. D.; Bruner, P. L.; Berrett, D. G. 1987. A field guide to the birds of Hawaii and the tropical Pacific. Princeton University Press, Princeton.

Rowe, S.; Empson, R. 1996. Distribution and abundance of the Tanga'eo or Mangaia Kingfisher (Halcyon tuta ruficollaris). Notornis 43: 35-42.

Further web sources of information
Explore HBW Alive for further information on this species

View photos and videos and hear sounds of this species from the Internet Bird Collection

Text account compilers
Benstead, P., Derhé, M., O'Brien, A.

IUCN Red List evaluators
Butchart, S., Symes, A.

Recommended citation
BirdLife International (2016) Species factsheet: Acrocephalus kerearako. Downloaded from on 28/10/2016. Recommended citation for factsheets for more than one species: BirdLife International (2016) IUCN Red List for birds. Downloaded from on 28/10/2016.

This information is based upon, and updates, the information published in BirdLife International (2000) Threatened birds of the world. Barcelona and Cambridge, UK: Lynx Edicions and BirdLife International, BirdLife International (2004) Threatened birds of the world 2004 CD-ROM and BirdLife International (2008) Threatened birds of the world 2008 CD-ROM. These sources provide the information for species accounts for the birds on the IUCN Red List.

To provide new information to update this factsheet or to correct any errors, please email BirdLife

To contribute to discussions on the evaluation of the IUCN Red List status of Globally Threatened Birds, please visit BirdLife's Globally Threatened Bird Forums.

Additional resources for this species

ARKive species - Cook Islands reed-warbler (Acrocephalus kerearako) 0

Key facts
Current IUCN Red List category Near Threatened
Family Sylviidae (Old World warblers)
Species name author Holyoak, 1974
Population size Unknown mature individuals
Population trend Decreasing
Distribution size (breeding/resident) 70 km2
Country endemic? Yes
Links to further information
- Additional Information on this species