Radley et al. • LANDBIRD MOLT ON SAIPAN 
591 
absent and the DPB is complete and proceeds in 
typical sequence. Juveniles exhibit white scallop¬ 
ing on the secondary coverts and light gray 
scalloping on the breast. The covert scalloping is 
more reliable for assigning age of worn birds than 
the breast scalloping, which can wear off. The 
blue or turquoise color on the inner vane of the 
flight feathers is reduced in juveniles, whereas in 
adults the coloring extends almost to the edge ot 
the feather on both the inner and outer vanes. 
Females have greenish-olive backs and turquoise- 
green wings, tail, and eye-stripe, whereas males 
have turquoise backs and bright blue wings, tail, 
and eye-stripe. These plumage traits occur in all 
age classes but colors average brighter in DCB 
than in FCJ individuals. Juvenal outer primaries 
are narrow and tapered, whereas basic primaries 
are broad but are, on average, narrower for 
females than for males. Females exhibit BPs, 
which may also occur for males. It is not known 
whether CPs occur in males. Biometrics suggests 
slight reverse sexual size dimorphism and appears 
to be of limited use for assigning gender 
(Table 1). 
Micronesian Myzomela (Myzomela rub rut ra ; n 
= 32 specimens, 121 individuals, 142 captures). 
The PF is incomplete to complete and includes 
body feathers, secondary coverts, and some to all 
primaries, secondaries, primary coverts, and 
rectrices in typical sequence. The DPB is 
complete but can be protracted and suspended. 
Juveniles (FCJ) often exhibit fleshy yellow gapes 
and have not yet initiated molt. Contrasts are often 
observed between inner primaries and outer 
secondaries due to protracted and/or suspended 
molt and normal fading and wear. FC’F individuals 
often retain blocks of middle secondaries, and, 
less often, outer primaries and primary coverts, 
which are more tapered, worn, and faded than 
replaced feathers. FCF females have brown 
formative flight feathers and mottled brown and 
red body plumage, whereas FCF males have dark 
brown formative flight feathers and red body 
plumage mottled brown. DCB birds have one 
feather generation, although a gradient of fading 
and wearing is often evident within the primaries 
and secondaries. DCB females can be quite red 
with brown mottling and medium brown wings 
while DCB males are bright red with black wings. 
Plumage is useful for assigning age and gender, 
whereas biometrics appear to be of little help with 
the latter (Table 1). The extent of skull pneuma- 
tization is difficult to ascertain because of the 
species’ dark, non-transparent skin. BPs and CPs 
are reliable for classification of males and females 
during breeding periods. 
Rufous Fantail (Rhipidura rufifrons', n = 41 
specimens, 821 individuals, 1,299 captures). The 
PF is usually partial and includes some body 
feathers, some to all (range =■ 2-9) greater coverts 
and, at times, the carpal covert. Some individuals 
undergoing a complete molt in September- 
October 2010 appeared to be young and were 
possibly undergoing a complete PF but may also 
have been hatched in late winter and undergoing a 
second prebasic molt after a PF in the spring. The 
DPB is complete but can be protracted and/or 
suspended. Moll can be in typical sequence or 
occasionally primaries can commence replace¬ 
ment within the tract and proceed both proximally 
and distally. Juvenal greater coverts, and occa¬ 
sionally carpal covert and alula, are brown with 
distinct rufous-buff tips and edging that fade with 
age. whereas basic coverts are uniformly brown 
with or without thin rufous edging. FCF in both 
males and females shows moll limits within the 
greater coverts, between the outer greater coverts 
and the carpal covert, or occasionally between the 
carpal covert and the alula. Neither males nor 
females show suspension limits or molt dines in 
the primaries, as can be shown by DCB 
individuals. Juvenal flight feathers and primary 
coverts on FCF birds are duller brown and more 
tapered than basic feathers on DCB birds. Extent 
of skull pneumatization can be useful for 
assigning age classes. Juveniles exhibit large skull 
windows that slowly pneumatize resulting in 
small windows being visible in some FCF 
individuals post-PF; skulls in all DCB individuals 
are completely pneumatized. Males and females 
are similar in both plumage and biometrics 
(Table 1), but both CPs and BPs are reliable for 
assigning gender of breeding birds. 
Nightingale Reed Warbler (Acmcephalus lusci- 
nius; « = 8 specimens. 14 individuals, 17 
captures). Both PF and DPB arc complete and 
appeal- to proceed in typical sequence. FCJ and 
DCB are similar, but juvenal primaries and 
secondaries are slightly more rounded and rectrices 
are thinner and more tapered than basic rectrices. 
Skulling can be reliable for separating FCJ and 
FCF birds but timing of reliability needs to be 
examined. Sample sizes are small, but wing chord 
may be useful for assigning gender, some overlap 
likely occurs (Table I). BPs and CPs are useful for 
assigning gender of breeding individuals. 
