Wing-Bars as Field-Marks 179 
WHITE-THROATED SPARROW WITH RING-BARS CONCEALED 
may not be observable even in species such as the Tree Sparrow, White- 
throated Sparrow and White-winged Crossbill. In a flock of any of these birds, 
you are pretty likely to see individuals with the wing-bars exposed; others 
showing them more or less obscurely, and some, though fewer, showing no 
trace of them. In other words, going only by the field-mark (alleged) standard, 
you will be pretty sure to discover a goodly number of ‘undescribed’ species 
in a flock of almost any of the white wing-barred Sparrows. 
shee A 
REDPOLL SHOWING WING-BARS 
