Wing-Bars as Field-Marks 



79 



WHITE-THROATED SPARROW WITH RING-BARS CONCEALED 



may not be observable even in species such as the Tree Sparrow, Whitc- 

 throated Sparrow and White-winged Crossbill. In a flock of any of these birds, 

 you are pretty Hkely 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. 



ft^V/Vf Fi. 



REDPOLL SHOWING WING-BARS 



