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THE WILSON JOURNAL OF ORNITHOLOGY • Vol. 124. No. 2. June 2012 
molt acquire a first basic plumage via a complete 
or ncarly-complete first prebasic molt that is 
equivalent with the second basic plumage and 
second prebasic molt in species or individuals that 
have a conventional first prebasic molt. Thus, 
plumages and molts that appear to be homologous 
have different names across taxa. Howell et al. 
(2003) adopted a two-part solution to the ’first 
basic problem’. First, they recharacterized and 
renamed the conventional first prebasic molt as a 
nonrecurring preformative molt because this molt 
is highly variable in timing and extent within and 
across avian taxa. Second, they deemed the 
prejuvenal molt and juvenal plumage to be 
homologous with definitive prebasic molls and 
basic plumages. The result of these modifications 
is the prejuvenal molt becomes the first prebasic 
molt and all birds acquire a second basic plumage 
~ 1 year after hatching via a second prebasic molt. 
Howell et al. (2003) also provided a definition 
for the 'first molt cycle', a term that was not 
defined by Humphrey and Parkes (1959, 1963). 
Howell et al. (2003: 639) defined the first molt 
cycle as “the period between the attainment of 
juvenal plumage and the acquisition of the next 
basic plumage via a complete, or nearly complete, 
molt that corresponds to a molt in the Simple 
Basic Strategy”. This strategy is characterized by 
the presence of only a prejuvenal molt followed 
by cyclical complete prebasic molts. The result is 
that “as a rule the first molt cycle has a duration 
similar to subsequent basic [molt] cycles” 
(Howell et al. 2003: 639). 
Four commentaries (Jenni and Winkler 2004, 
Piersma 2004, Thompson 2004, Willoughby 
2004) on Howell et al. (2003) and a reply by 
Howell et al. (2004) were published. Thompson 
(2004) was strongly critical, while Piersma (2004) 
was supportive, Jenni and Winkler (2004) and 
Willoughby (2004) were supportive of the pro¬ 
posed recharacterization of the conventional first 
prebasic molt, but maintained the modified H-P 
system still does not effectively reflect phyloge¬ 
netic molt homologies due to the wide variety in 
molts and plumages. These authors remained 
advocates of the traditional, life-history-depen- 
dent approach to naming molts and plumages 
rejected by Humphrey and Parkes (1959). Jenni 
and Winkler (2004) also were critical of the 
definition of the terms ’molt’ and ’first moll 
cycle' in Howell et al. (2003). Despite the 
concerns raised by these commentaries, the 
modifications to the H-P system proposed by 
Howell et al. (2003) have been widely used in 
ornithological literature, including revised species 
entries in The Birds of North America Online 
It currently is unclear whether ornithologists 
should use conventional H-P terminology or Un¬ 
modified H-P terminology of Howell et al. (2003) 
to describe avian molts and plumages iDitiinar.n 
and Cardiff 2009). Moreover, the so-called ‘first 
basic problem' identified by Howell el al. (2003) 
now has a second dimension because some 
ornithologists communicate about avian molts 
and plumages without stating which system of 
molt terminology is being used. Thus, it is 
uncertain whether the terms ‘first prebasic molt’ 
and ’first basic plumage' refer to the 'prejuvenal 
molt' and 'juvenal plumage’, respectively, as 
proposed by Howell et al. (2003), or a typically 
partial, postjuvcnal molt and resulting plumage 
under conventional H-P terminology. Moreover, 
the recharacterization of the conventional first 
prebasic molt as a oncc-in-a-lifetime preformative 
moll has significant consequences in identifica¬ 
tion of presumed homologies among molls and 
plumages, particularly with respect to homologies 
involving this moll. 
In this article I re-evaluate the modifications to 
the H-P system proposed by Howell et al. (2003). 
I first discuss an interpretive issue with the 
definition of ’molt’ in Humphrey and Parkes 
(1959) and the revised definition of this tenn 
adopted by Howell et al. (2003). Next. I evaluate 
Howell et al.’s proposed recharacterization of the 
prejuvenal and conventional first prebasic molts 
and resulting plumages by discussing each of the 
prejuvenal. conventional first prebasic. and first 
prealtemate molts and resulting plumages I 
maintain these modifications to the H-P system 
arc premature for a variety of reasons, including 
the lack of supporting evidence. These modifica¬ 
tions also are unnecessary in light of a proposed 
interpretation of the H-P system that resolves the 
'first basic problem' without recharacterizing the 
status of the prejuvenal and conventional first 
prebasic molts (Table I). I also discuss the 
beginning and end of the first molt cycle for 
purposes of the H-P system. 1 maintain the H-P 
system can be interpreted to start the first molt 
cycle with commencement of the initial acquisi¬ 
tion of contour (or pennaceous) feathers and 
provide a fixed point to start a nomenclature o! 
molts and plumages (Table I). I then discuss the 
appropriate way to view presumed homologies 
among molts under the H-P system and the four 
