||Acrocephalus rimitarae (Murphy & Mathews, 1929)
||Rimatara Reed-warbler, Rimatara Reed-Warbler
Acrocephalus rimatarae (Murphy & Mathews, 1929) [orth. error]
||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.
Acrocephalus rimitarae (del Hoyo and Collar 2016) was previously listed as A. rimatarae.
||17 cm. Large warbler with relatively short bill. Adult olive-brown above, yellowish-white below, with dark streak through eye and pale supercilium. White feathers variably and often asymmetrically scattered among darker feathers, often producing large blotches. Voice Loud chack-chack or high-pitched chirp. No song reported.
|Red List Category & Criteria:
||Dutson, G., Millett, J. & Raust, P.
||Derhé, M., Mahood, S., O'Brien, A., Pilgrim, J., Shutes, S., Stattersfield, A., Wheatley, H.
This species is listed as Critically Endangered because it has an extremely small range on one island and is considered to be undergoing a decline as a result of habitat destruction and invasive species.
|Previously published Red List assessments:|
- 2017 – Vulnerable (VU)
- 2016 – Vulnerable (VU)
- 2012 – Vulnerable (VU)
- 2008 – Vulnerable (VU)
- 2006 – Vulnerable (VU)
- 2004 – Vulnerable (VU)
- 2000 – Vulnerable (VU)
- 1994 – Not Recognized (NR)
- 1988 – Not Recognized (NR)
|Population:||Various population estimates have been made which differ widely depending on methods used. Point count observations in 2002 gave a population estimate of 5,000 birds (Blanvillain 2002). Territory mapping techniques used by Thibault and Cibois (2006a) gave estimates of 1,777-2,567 breeding birds in 2004 (roughly 2,665-3,850 individuals), and transects gave estimates of 740 (Raust and Sanford 2002), 675 (Gouini 2004) and 670 (Albar et al. 2009), though applying a correction to account for differences in methodology would lead to higher estimates from these (Blanvillain et al. 2015). The most recent estimate generated is 1,780-2,781 individuals (C. Blanvillain in litt. 2017). Taking into account corrections (see Blanvillain et al. 2015), the range of estimates fall into the range of approximately 900-3,850 individuals, which roughly equates to 600-2,600 mature individuals (G. Dutson in litt. 2016).|
Trend Justification: Given the threats the species may be facing, and the continuing degradation of its habitat, it is considered to be undergoing a slow ongoing decline (C. Blanvillain in litt. 2016 per G. Dutson in litt. 2016). Population estimates made using similar methodologies in 2006 and 2017 suggest a reduction (Thibault and Cibois 2006a; C. Blanvillain in litt. 2017).
|Current Population Trend:||Decreasing|
|♦ Number of mature individuals:||600-2600||♦ Continuing decline of mature individuals:||Yes|
|♦ Extreme fluctuations:||No||♦ Population severely fragmented:||No|
|♦ No. of subpopulations:||1||♦ Continuing decline in subpopulations:||Unknown|
|♦ Extreme fluctuations in subpopulations:||No||♦ All individuals in one subpopulation:||Yes|
|♦ No. of individuals in largest subpopulation:||100|