Junda et al • RUFOUS FANTAIL PRIMARY MOLT 
683 
TABLE 1. Molt patterns of Rufous Fantails captured in 2009 and 2010 at TMAPS stations on Saipan. Younger (SCB) 
individuals and females were more likely to have a primary 2-4 strategy then older (DCB) individuals and males. 
n 
DCB*-" 
SCB"' 
Males" 
Females" 
Primary 1 group 
108 
54 
34 
20 
5 
Primary 2^1 group 
66 
8 
32 
8 
14 
Primary 2 d 
2 
0 
1 
1 
I 
Primary 3 d 
51 
6 
26 
7 
11 
Primary 3/4 d 
8 
1 
2 
0 
1 
Primary 4 d 
5 
1 
3 
0 
1 
' !X’B (Definitive Cycle Basic) individuals are those Undergoing ai least their third prebasic molt. 
b Age and gender could not be ascertained for all captures. 
L SCB (Second Cycle Bavin individuals are those undergoing their second prebasic molt 
■' Values for P 2, P 3. P 3/4, and P 4 represent subsets of die primary 2-1 group. 
October 2010 on Saipan (15 12' N. 145 45' E). a 
tropical Pacific island in the Northern Mariana 
Archipelago (Radley et al. 2011). Each mist- 
netting station was operated for 6 hrs once every 
10 days following protocols established bv (be 
Institute for Bird Populations (DcSantc et al. 
2009). All unhanded birds were individually 
marked with numbered aluminum leg bands and 
many were classified to age and gender (Pyle el 
al. 2008. Radley et al. 2011). Wing chord was 
measured (± 1.0 mm) as unflattened right wing 
from wrist to tip of the longest primary. Mass 
(± 0.1 g) was measured using a digital scale. 
Rufous Fantails typically have a partial preforma- 
tive moll and do not replace primaries or 
secondaries until the second prebasic molt. Age 
was assigned based on extent of skull pneumati- 
zation, plumage, and moll-limit criteria (Radley et 
al. 2011), and verified through recapture data 
when available. Age codes were defined based on 
plumage cycle (Wolfe et al. 2010) and birds were 
categorized as either second-cycle basic (SCB). 
including (hose undergoing (lie second prebasic 
molt, or definitive-cycle basic (DCB). including 
(hose undergoing (lie third or later prebasic molt. 
Individuals in breeding condition were assigned 
as male by the presence of cloacal protuberance or 
female by presence of a brood patch (Pyle 1997. 
Radley et al. 2011). 
The presence or absence of symmetrical flight- 
feather molt was recorded for all birds captured. 
Both wings were scored for most captures to 
confirm sequence and assess symmetry between 
wings. We categorized individuals based on moll- 
score patterns (using the strategies ot Rohwer 
2008) as either showing distal sequential molt 
from P 1 (primary-1 group), showing molt centers 
at P 2, P 3, P 3/4, or P 4 and both distal and 
proximal replacement (primary 2-4 group), or 
showing distal molt between P 5 and P 10 
(primary 5-10 group). A center at P 3/4 was 
assigned when these two growing primaries were 
equal in length, indicating molt had commenced 
with both feathers at about the same time. 
Replacement of primaries 1-3 can be rapid and 
close to synchronous in passerines (Pyle 1997), 
and wc were careful to ensure that P 1 was fresher 
than P 2 (and thus replaced earlier) in those 
categorized into the primary-1 group and in which 
both of these primaries were fully grown. We did 
not identify commencement point among prima¬ 
ries 1 to 4 in the primary 5-10 group and these 
birds are not considered further. 
RESULTS 
We captured 1.086 Rufous Fantails a combined 
1,728 times during 2009 and 2010; 306 individ¬ 
uals were captured a combined 448 times when 
primaries were molting, and we scored primaries 
for 343 captures. Molt center and sequence among 
primaries i-4 were categorized during 174 molt 
episodes for 166 birds (8 birds were scored twice 
during prebasic molt episodes in both 2009 and 
2010). All documented molt sequences were 
symmetrical between wings within one full-grown 
feather, and no birds had varying molt centers on 
different wings. 
Sequential replacement from P 1 was recorded 
lor 108 ot 174 molt episodes (62%) and a center 
among primaries 2-1 from which molt proceeded 
bi-directionally was recorded for the remaining 66 
(38%) episodes (Tables 1, 2; Fig. 1). Most birds 
in the primary 2-4 group (77%) initiated molt at 
primary 3 (Table 1). and the distribution among 
centers (including 3% at P 2. 12% at P 3/4. and 
8% at P 4) was normal (Kolmogorov-Smimov test 
for normality: D = 0.042. P > 0.15). The mean 
starting point within this group was 3.11. or just 
