Kurt
You can tell the difference between male and female adults, and hatch year 
birds.  Get one of the hummingbird guides and take a look.  There are two 
good ones available.  I think Steve Howell did one and Sheri Williamson did 
one.   Do a Google search.  The key is the throat.
George

----- Original Message ----- 
From: "Kurt R. Schwarz" <>
To: <>
Sent: Thursday, September 11, 2008 5:33 PM
Subject: [MDOSPREY] Distinguishing Ruby-throats?


Does anyone know, is it even possible, to distinguish immature Ruby-throated 
Hummingbirds from females?  A male, with incipient gorget feathers should be 
easy, but...  I encounter window kills frequently at work, and am keeping 
track, but remain flummoxed by those white-throated mites, most of which 
show some uniform stippling.

Kurt Schwarz
HowCo
goawaybird at comcast dot net