SPHENOPHRYNE - American Museum of Natural History

48 BULLETIN AMERICAN MUSEUM OF NATURAL HISTORY NO. 253
those from Normanby are the largest: three
from Normanby are 36 to 38 mm, contrasted
to a maximum of 37 mm in all other samples.
The smallest frogs are those of the Huon
Peninsula, where adult females (N 21)
measure from 32 to 40 mm and adult males
from 28 to 33 mm (N 7). Samples intermediate
between these extremes, but not necessarily
identical among themselves, include
those from Goodenough Island, Mt. Dayman,
the Wau-Garaina area, and Simbu Province.
Visual comparison of regression lines for
several proportions in four samples of palmipes
shows little geographic variation. Only
in the case of slightly larger eyes in the Normanby
Island sample does one line stand out
much from the rest. Regression and proportion
statistics are in tables 2 and 3.
ILLUSTRATIONS: 3rd finger terminal phalanx,
fig. 71P; premaxilla, fig. 64G; sacral
region, fig. 73C; vomer, fig. 65O; finger disc,
fig. 51; hand and foot, fig. 56D. Kuramoto
and Allison (1989) illustrated the karyotype.
CALL: Menzies (1976: 55) mentioned ‘‘a
quiet clicking noise which I believed was
made by a palmipes by the side of a forest
stream.’’ Verification that palmipes calls
(though lacking vocal slits) is needed.
COMPARISONS WITH OTHER SPECIES: Within
its geographic range there is no Austrochaperina
species with which palmipes could
readily be confused, as the combination of
extensive toe webbing and relatively large
digital discs is unique. The closely related
species rivularis, macrorhyncha, and basipalmata
are allopatric to palmipes, so far as
is known, and either lack or have only slight
toe webbing.
HABITAT AND HABITS: This is a riparian
species of foothill and lower montane rainforest,
ranging in elevation from less than
100 m to at least 1700 m. I have found these
frogs by day under streamside rocks and at
night on mossy rocks in small streams. Menzies
(1976: 55) reported that frogs ‘‘were
clinging to wet rocks, especially near waterfalls
. . . . When disturbed, they dived into
the water and reappeared a little distance
away.’’ For descriptive accounts of areas
where this species occurs, see Brass, 1956
(Mt. Dayman and Goodenough Island) and
1959 (Normanby Island).
Although it probably is the most aquatic
of the New Guinean microhylids, A. palmipes
still must resort to land for breeding. Dr.
Allen Allison (personal commun.) reports an
individual attending eggs ‘‘in a depression
under leaf litter along the bank of a small
stream.’’ A female about 35 mm SVL contained
19 ova each of which was 3 mm in
diameter.
DISTRIBUTION: This species occupies the
Huon Peninsula, the northeast slopes of the
mountains from the Huon Gulf to the eastern
tip of New Guinea, and the D’Entrecasteaux
Islands (not yet recorded from Fergusson Island).
In addition, there is an apparently isolated
population on the west side of the central
ranges in the Purari River drainage of
Gulf and Simbu Provinces (fig. 29). This isolated
area is more than 200 km from the
nearest locality for the species to the east in
Morobe Province. Additional collecting may
be expected to narrow the gap, but there are
few passes as low as the maximum elevation
that palmipes is known to attain. It is likely
that the populations truly are disjunct. A similar
apparent range disjunction occurs in another
microhylid frog, Cophixalus cheesmanae
(Zweifel: 1979, fig. 8). Records range in
elevation from 60 to 1750 m.
LOCALITY RECORDS AND SPECIMENS EXAM-
INED: PAPUA NEW GUINEA: Gulf Prov.:
Camp III, Nimi River, 13.5 km S, 1 km E
Soliabedo, 425 m (AMNH A79973; MCZ
A111901–111914). Simbu Prov.: Camp I,
13.5 km S, 2 km E Karimui, 1070 m (MCZ
A111918); Soliabedo, 550 m (MCZ
A111916, 111917); Camp II, Pio River, 6.5
km S, 1 km E Soliabedo, 300 m (MCZ
A111919–111922); between Camp II, 6.5
km S, 1 km E Soliabedo, and Weiana, 8 km
S, 1 km E Soliabedo, 430–730 m (MCZ
A133017); Haia Village, 720 m, 14500,
642(AM 32257); Haia Bush Camp, 880 m,
14501, 640 (AMS R32443, R32450,
R32451, R32471–32476). Morobe Prov.:
Ulap, 800–1100 m (BPBM 5322); Boana,
880 m (MCZ A111874–111895); Areganang
(AMNH A81200–81209); Gang Ck., 1340 m
(AMNH A75048–75053 [75050 and 75053
dry skeletons], A76038–76047); near Zangaren,
1370 m (AMNH A76031, A76032);
Masba Ck. (AMNH A76033); Numbut, 1220
m (AMNH A76034–76037); Tewep, 1350
m, 11 km E, 8 km N Boana (BPBM 1048);