1.It is a very big generalization, and some species are exceptions, but generally first summer individuals can only be separated by retained juvenile remiges and rectrices or by moult limits in the greater coverts.
这是一个很概括的看法,且某些鸟种是例外,但一般而言一龄夏羽个体只能以还留著的幼鸟飞羽和尾羽,或大覆羽的换羽界限来区分.
