Acrocephalus luscinius   (Quoy & Gaimard)

Nightingale Reed Warbler
(Acrocephalus luscinius)

syn. Thryothorus luscinius (Quoy & Gaimard)


Mariana Islands: Guam

local name:

Ga'kaliso (Chamorro)
Ga'karriso (Chamorro)

size: ca. 17 cm (length)

extinction date: last seen 1969

The Nightingale Reed Warbler was an endemic species of Guam, the reed warbler populations of all other islands in the Mariana island chain were until recently treated as subspecies of this species, but are now considered as distinct species.

The Nightingale Reed Warbler was restricted on Guam to cane thickets in fresh and brackish water marshes, which on the island have largely been drained and converted to other uses. Hence the reasons for the extinction of this species lie mainly in the extensive destruction of its habitat. The unintentional introduction of the Brown Tree Snake (Boiga irregularis (Merrem)), which has led to the extinction of nearly all of Guam's native bird species, plays a minor role here.


The island of Alamagan in the north of the Maraina archipelago is still harbouring a smaller population of reed warblers (about 300 birds), which hitherto have been assigned without any reservation to this species (resp. formerly subspecies), which, however, in a biogeographical sense must be considered completely impossible (hereto see map).

The birds from the island of Alamagan are either most closely related to the species from Alamagan's neighbor island, Pagan, the Pagan Nightingale Reed Warbler (Acrocephalus yamashinae (Takatsukasa)), or even represent a distinct species.


reed warbler species of the Marianas known from specimens

Depiction: Alexander Lang


- H. Douglas Pratt, Phillip L. Bruner, Delwyn G. Berrett: A Field Guide to the Birds of Hawaii and the Tropical Pacific. Princeton University Press 1987
- James D. Reichel; Gary J. Wiles; Phil O. Glass: Island extinctions: the case of the endangered Nightingale Reed-Warbler. Wilson Bull. 104(1): 44-54. 1992
- Peter Kennerley: Reed and Bush Warblers. Christopher Helm, 2010
- Alice Cibois; Jon S. Beadell; Gary R. Graves; Eric Pasquet; Beth Slikas; Sarah A. Sonsthagen; Jean-Claude Thibault; Robert C. Fleischer: Charting the course of reed-warblers across the Pacific islands. Journal of Biogeography 38(10): 1963-1975. 2011