228 
C.B. and D.W. Frith 
feathers, and those of the upper breast, have far 
less extensive black edges than in birds to the south 
and the southeast. This gives these parts of the bird 
a far more uniformly chestnut look (as in the 
crown) than the much blacker appearance of these 
parts in birds from the Pilbara and Murchison 
(Figure 2). 
The 'blackish' colour in the wings (primaries and 
secondaries) and upper tail (notably the central 
pair of rectrices) is less black, tending more to 
brown, in the North West Cape birds than in those 
to the east and southeast. This is a slight but 
nevertheless consistent difference found in all five 
North West Cape birds. The pale broad edging to 
the primary and secondary wing coverts in four of 
the North West Cape birds is similar in colour to 
those in adjacent areas but in Museum of Victoria 
female skin HLW 6591, it is rich chestnut, as is the 
back spotting of all five North West Cape birds. 
The rich chestnut of the sides of the breast, 
flanks and thighs is most noticeably more extensive 
in North West Cape birds than in those to tire east 
and southeast. In birds from the latter areas the 
chestnut is confined more to the sides of the 
abdomen, the flanks and the thighs, where the 
colour is less intense. In North West Cape birds the 
rich chestnut extends all the way up the sides and 
further out onto the sides of the flanks, abdomen 
and breast than in the other birds (in which it is 
mostly concealed by the wings), and this joins the 
chestnut of the throat and sides of the neck. The 
Table 1 Mean measurements (boldface), standard 
deviations and sample sizes for 40 Western 
Bowerbird Cltlamydera guttata specimens' from 
North West Cape (C. g. carteri), Hamersley Range 
and Murchison River area (C. g. guttata) of 
Western Australia. 
Wing Tail Tarsus Bill Bill Total 
length length length length width head 
length 
North West Cape : 137 
91 
36.6 
30.2 
7.6 
57.1 
2.77 
3.19 
0.61 
1.00 
0.43 
- 
7 
7 
7 
7 
7 
1 
Hamersley Range 3 149 
94 
38.4 
30.6 
7.4 
58.4 
1.27 
9.96 
1.37 
0.78 
0.44 
1.09 
13 
12 
13 
13 
13 
12 
Murchison River* 148 
95 
38.9 
30.4 
7.5 
58.0 
2.31 
5.35 
1.15 
1.20 
0.32 
1.07 
20 
20 
20 
20 
20 
19 
1 12 from Museum of Victoria, 11 Western Australian 
Museum, 10 National Wildlife Collection, CSIRO, 5 
American Museum of Natural History, 1 South Australia 
Museum and 1 The Natural History Museum, Tring. 
; 6 females and 1 adult male. 
3 7 adult males, 2 subadult males and 4 females (including 1 
from Onslow, 1 from Oakover River, 1 from Callawa and 1 
from the Sherlock River - see Figure 1). 
1 11 adult males, 2 subadult males and 7 females. 
only exception to this is a crestless female specimen 
in the WAM (A4126) from Yandil Station on the 
West Murchison River which has rich and 
extensive chestnut similar to the North West Cape 
birds. It shows no yellow on its underparts, 
however, and has the crown, mantle and back 
plumage of tire East Murchison birds while its chin 
and throat feathering is somewhat intermediate in 
coloration and marking. Thus, while it does exhibit 
the rich extensive chestnut otherwise found only in 
North West Cape birds, it lacks the yellow 
underparts of North West Cape birds. Its 
upperparts are as in East Murchison birds and it is 
significantly and exclusively larger than North 
West Cape birds in all but bill length (= 29.7 mm, 
the length of the shortest-billed North West Cape 
bird). Thus, the Yandil bird is an atypical 
Murchison River area individual that is clearly not 
associated with the geographically remote (Figure 
1) and distinctive North West Cape birds. 
The specimen of C. guttata carteri in the AMNH 
(679152) collected by Carter at Hooroomooroo, 
North West Cape on 6 August 1916, has the same 
appearance as the above North West Cape 
specimens, with the extensive chestnut thighs, 
flanks and sides of the breast. The throat is 
similarly more buff and less black as in other North 
West Cape birds, but unlike one from Onslow and 
those from other adjacent areas in the AMNH 
collection. The crown feathers of the AMNH 
specimen are streaked and spotted dark chestnut 
with fine black outer edging and lack silvery tips; 
the nuchal crest is small. In comparison the bird 
from Onslow (AMNH 679153) has the crown only 
spotted dark chestnut, with much silver tipping to 
the feathers; the nuchal crest is large. The Onslow 
bird has far less extensive chestnut on its flanks 
than the North West Cape birds. A bird from 10 
miles north of Tambrey, Sherlock River, which is 
directly north of the central Hamersley Range, is 
similar to the Onslow specimen. Thus the Onslow 
and Sherlock River birds are unlike the North West 
Cape birds but are like those from Hamersley 
Range. 
The single specimen (1931.8.1.1) of carteri in the 
BMNH was collected by Carter on 9 August 1916 
at North West Cape. In general markings and 
coloration it is extremely similar to the specimen in 
the AMNH and, while its nuchal crest is slightly 
larger than in North West Cape skins in the 
Museum of Victoria and AMNH, it is 
conspicuously smaller than in birds from Onslow, 
Sherlock River, Hamersley Range and East 
Murchison area. 
Table 1 summarises the measurements of the 
seven North West Cape specimens and of an 
additional 33 C. guttata skins from adjacent areas 
held at various museums. Wing and tail lengths of 
the birds of the Hamersley and Murchison areas 
