===============+=====+=========+=========+=============+=============
| | | | Exposed |
SEX | No. | Wing | Tail | culmen | Tarsus
---------------+-----+---------+---------+-------------+-------------
Adult males | 7 | 74 | 64 | 21.0 | 28.5
| | (72-77) | (62-68) | (19.5-22.5) | (27.0-30.0)
| | | | |
Adult females | 11 | 69 | 58 | 21.0 | 26.5
| | (65-74) | (55-61) | (19.5-22.0) | (25.0-29.0)
---------------+-----+---------+---------+-------------+-------------
_Specimens examined._--Total number, 23 (9 males, 14 females), as
follows: Palau Islands, USNM--Koror, 5 (Nov. 7, 9, 11, 18,
19)--Peleliu, 4 (Aug. 29, 30, Sept. 4, Dec. 5)--Ngabad, 1 (Sept.
11); AMNH--exact locality not given, 13 (Nov., Dec.).
_Nesting._--Nehrkorn (1879:399, 404) records the egg of _Psamathia_
from Palau. The NAMRU2 party obtained no evidence of nesting of
this bird in August and September, 1945. In 1931, Coultas secured
birds in November and December, which had enlarged gonads. Marshall
(1949:219) records breeding in November and December.
_Molt._--Most of the skins taken from August to December have worn
or molting feathers. Apparently there is a high point in the
molting process in autumn and early winter.
_Food habits._--Stomachs obtained from birds taken by the NAMRU2
party in August and September contained parts of insects and small
seeds. One stomach contained about one-half cc. of parts of
insects. Coultas (field notes) found the bird scratching "on the
ground for seeds as well as working in the low trees and bushes."
Marshall (1949:212) records insects and snails as food items.
_Remarks._--_Psamathia_ has the habit of a typical bushwarbler,
occurring in jungle undergrowth and along woodland margins. In 1945,
specimens were obtained by the NAMRU2 party in the scrub vegetation
which was growing over the devastated battle areas of Peleliu. The bird
was not common in this habitat, nor was it very numerous on the smaller
offshore islands. Coultas (field notes) found the bird to be rather tame
and frequently to live close to human habitation. Its call, as noted by
Coultas, is a loud whistle that breaks off into a beautiful song. The
bird is quick in its movements; one seen by the writer at Ngabad was
constantly moving about in low, second-growth vegetation and was making
a low, whistling call. The resemblance of _Psamathia_ to _Rukia
palauensis_ is noteworthy. These two unrelated birds live together in
jungle areas, although _Psamathia_ is perhaps confined more to the
forested undergrowth and is more solitary in its habits. Aside from its
longer legs and bill, _Psamathia_ closely resembles _Rukia_ in shape and
coloration. They appear to have developed along somewhat similar
evolutionary lines with regard to structure, color and ecologic
requirements.
The Palau Warbler was first discovered by Captain Tetens and described
as belonging to a new genus by Hartlaub and Finsch (1868a:5). In the
original description the authors remark that, "The generic position of
this new form is in the _Calamoherpe_ group; the feet are the same as in
_Calamoherpe_; but the beak is weaker and slenderer, and the wings are
very different. _Calamoherpe_ has the first quill quite spurious, the
third is the longest, and the second and sixth are subequal. In
_Calamoherpe_ there are twelve tail-feathers; in _Psamathia_ I can find
only ten. _Tatare_ is a very different form, with a scutellated tarsi, a
very different structure of the plumage, a much more elongated beak, and
a twelve-feathered tail. _Tatare syrinx_ is a typical Calamoherpe. In
the structure of the wing of _Psamathia_, there seems to be a great
resemblance to the genus _Arundinax_ of Blyth, a form with which it is
not in my power to compare." The genera _Calamoherpe_ and _Tatare_ are
now included in _Acrocephalus_; the describers were comparing the Palau
Warbler with the reed-warblers of Micronesia and Polynesia.
Sharpe (1883:93) writes that the Palau Bush-warblers are "Aberrant reed
warblers, and should, in my opinion, be placed in future classifications
of the Cichlomorphae near the genera _Cettia_ and _Acrocephalus_, from
which they are separated by their larger first primary only. Through
_Megalurus_ and _Sphenoeacus_ they approach the grass-warblers and
Cisticolae especially."
Mayr (1941b:203) cites _Psamathia_ as an example of "restricted
endemism" and points out that the nearest relative occurs in the
Philippines. Delacour (1942:514), in a discussion of the bush-warblers
of the genera _Cettia_, _Bradypterus_ and related forms, says,
"_Psamathia annae_, from Palau Islands, is related to _Cettia_,
differing mainly in its much longer bill and legs."
_Psamathia_ is a specialized bush-warbler and has followed a pattern of
evolution which characterizes some of the other island birds in that the
bill and legs are long and the wing is rather short and rounded.
_Psamathia_ resembles many of the bush-warblers, as well as the
reed-warblers {_Acrocephalus_); in general, body coloring being paler
below and darker above. It differs from _Acrocephalus_ by having a
longer tenth primary, smaller second and third primaries, only ten tail
feathers, a more rounded wing, differently shaped nostrils, and by much
softer plumage (the latter character is found also in _Collurcincla
tenebrosus_ and _Cleptornis marchei_ of Micronesia). Rather than being
related to the reed-warblers, as was supposed by Hartlaub and Finsch,
_Psamathia_ seems closest to _Cettia_, especially to _Cettia_
(_Horeites_) _diphone seebohmi_ of the Philippine Islands. _Psamathia_
has a longer bill than this bird, but the general appearance and
structure of the feet, tail, wing, body and bill are the same.
=Acrocephalus luscinia luscinia= (Quoy and Gaimard)