Konyukhov and Kitaysky 



Chapter 2 



The Asian Race of the Marbled Murrelet 



Rectrix molt begins just after the beginning of primary 

 molt. They are lost outwards from the inner pair. Contour 

 feathers likely begin to molt in September. Two birds taken 

 in early September in Avacha Bay had definite alternate 

 plumage, but their throats and cheeks were almost white. 

 A very pale bird in alternate plumage was taken on Sakhalin 

 Island on 20 March 1969. The ground color was almost 

 white, and all dark colors were replaced by yellow-brown. 



Shibaev (1990) describes a molting pattern in young 

 birds as follows: "The change of nesting plumage into the 

 first winter plumage takes place during September-October 

 in young birds. The murrelets from the southern parts of the 

 Far Eastern region of Asia, that had been collected in August, 

 had a nesting plumage and had no signs of molt. The birds, 

 collected in southern Primorye in the last week of October 

 and in November, had changed from the nestling plumage 

 into the first winter plumage already (excluding primaries, 

 secondaries and tail feathers)." 



Body Measurements 



The Asian subspecies of the Marbled Murrelet is larger 

 (tables 2 and 3) relative to the nominate race. This includes 

 larger body mass (by about 50-70 g); larger culmen length 

 (by about 5 mm); and larger wing length (by about 5-6 mm). 

 See also Sealy and others (1982) and Piatt and others (1994) 

 for discussion of body size characteristics. 



Besides these mensural differences (Sealy and others 

 1982), these subspecies (or species) have differences in 

 coloring of both their basic and alternate plumages. Jehl 

 and Jehl (1981) noted that the North American Marbled 

 Murrelet has a more rufous and darker alternate plumage 

 than the Asian race, and has more pronounced spots near 

 the eyes. In the basic plumage there is more contrast between 

 the races (fig. 2). This can be seen by comparing pictures in 

 field guides, for example Robbins and others (1983) and 

 Wild Bird Society of Japan (1982). As with the basic 



Table 2 Measurements of Brachyramphus marmoratus perdix, showing mean and range 



Table 3 Measurements of Brachyramphus marmoratus perdix from museum specimens 



26 



USDA Forest Service Gen. Tech. Rep. PSW-152. 1995. 



