Bryan et al-A Google search of "juvenile vs. immature birds" revealed this: http://help.ebird.org/customer/portal/articles/1010509-what-is-the-difference-between-a-juvenile-and-an-immature-
eBird has a thorough FAQ section: http://help.ebird.org/customer/portal/topics/454401-frequently-asked-questions/articles
Cheers,Ryan
Ryan Douglas
Postdoctoral Fellow
310 Tucker Hall
University of Missouri
Columbia, MO 65211
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