Hawkins • THE 'FIRST BASIC PROBLEM' REVISITED 
413 
TABLE 2. Examples of North American Bird species 
equivalent in timing with subsequent prebasic molts. 
that have a uniformly-complete conventional first prebasic molt 
Species* 
Source' 
Anna's Hummingbird ( Calypte anna) 
Williamson 1956. Pyle 1997 
Nonhem Beardless-Tyrannulet (Camptostoma imberbef 
Pyle 1997 
1 lomed Lark ( Erenuiphila alpestrisf 
Pyle 1997 
Bam Swallow (llirundo rustica ) b 
Pyle 1997 
Bushtii ( Psaltriparus minimus)* 
Pyle 1997 
European Starling ( Stumus vulgaris ) h 
Pyle 1997 
Bachman's Sparrow ( Peucaea aestivalis ) h 
Willoughby 1986 
Cassin's Sparrow (P. ettssinii ) b 
Willoughby 1986 
Eastern Meadowlark (Stumella magnaf 
Pyle 1997 
Western Meadowlark (S. neglecta ) b 
Pyle 1997 
House Sparrow {Passer domesticus)* 
Pyle 1997 
Eurasian Tree Sparrow (P. manumus f' 
Pyle 1997 
J Includes species with conventional first prebasic molts that have identical timing as subsequent prebasic molts or that occur within I or 2. rarely 3 months of the 
tinting of subsequent prebasic molls due to time of hatching and presence of the prcjuvenal molt (Pyle 1997). 
b Mm a first basic plumage that is indistinguishable from subsequent basic plumages. 
c The Birds of North America Online. 
es a plumage that is indistinguishable from the 
definitive basic plumage (Table 2), There is every 
reason to assume the conventional first prebasic 
moll of these species is not only homologous with 
definitive prebasic molts but is itself definitive in 
nature. 
Howell et al. (2004: 207) maintained that 
complete conventional first prebasic molts repre¬ 
sent “one end of a continuum in which the 
preformative molt replaces from one to all of a 
bird's leathers”. A continuum in the extent of 
conventional first prebasic molts across avian taxa 
is not inconsistent with these molts being basic in 
nature and homologous with definitive prebasic 
molts. Moreover, the fact that one end of this 
continuum consists of young that undergo uni- 
formly-eomplete conventional first prebasic molts 
that are indistinguishable from definitive prebasic 
molts suggests this continuum represents levels of 
development of conventional first prebasic molts 
across species and not variability in nonrecurring 
preformative molts. 
Howell et al. (2003: 046) also maintained that 
complete conventional first prebasic molls are 
nonrecurring preformative molts because “they 
do not correspond to molts in the Simple Basic 
Strategy” and birds that have such molls “would 
gain an extra 'basic' plumage relative to the 
[Simple Basic Strategy!". All birds are consid¬ 
ered to reach molt maturity by means of the 
second prebasic molt under the system of Howell 
et al. (2003). despite significant morphological 
and behavioral differences and that birds do not 
uniformly acquire definitive plumage or reach 
sexual maturity at the same lime in their life 
cycles. This argument of Howell et al. (2003) 
indicates the artificial nature of their proposed 
modifications to the H-P system, which empha¬ 
size uniformity among species at the expense ol 
ignoring real and important interspecific variation. 
Howell et al. (2003: 647) acknowledged that 
from an evolutionary perspective "it is most 
parsimonious to consider molts and plumages 
present in definitive cycles to have homologous 
counterparts in the first cycle, unless good 
evidence exists to the contrary”. Howell et al. 
(2003, 2004) provided no scientific evidence to 
rebut this position. 
Howell et al. (2003) ultimately may be correct 
that conventional first prebasic molls are unique 
adaptations that allow birds to get through their 
first moll cycle. Absent scientific evidence to the 
contrary, however, it appears more reasonable to 
consider conventional first prebasic molts basic in 
nature as provided under the H-P system. The 
variability in the timing and extent of this molt 
reflects the effects of a wide variety of environ¬ 
mental, ecological, physiological, and behavioral 
factors (Payne 1972) on the molts of young, 
developing birds and the wide diversity across 
avian taxa. Thus, for example, it clearly is 
reasonable to presume that the conventional first 
prebasic molts of the California and Massachu¬ 
setts populations of House Finch (Carpodacus 
mexicanus) are basic in nature and homologous 
notwithstanding that they differ significantly in 
