I think that I can help Gail. the Juv have their upper part feathers with
buffy tipping. The greater coverts are also buffy beige. This helps in
determining the juvenile from the second year (SY) and the adult after
hatch year (AHY) birds. The greater coverts exhibit quite a bit of this
buffiness from the adults on the greater coverts. Its found just on the
end of these feathers. But I must tell you that you should beware because
a vast majority of the SWTH do not have this so easily visible. Sorry

Another way that you can tell is by the shape of the retricies (tail
feathers). They tend to be more pionted than the adult bird feathers,
which are more rounded, truncate. This can be hard to see in the field but
if you get close enough you may be lucky. Other than catching them in the
net that is about the best one can tell. Finally, these characteristics of
buffiness in SWTH and a few other species of juveniles lasts for only a few
months in the summer until they get there first body moults. Which should
be from now until the end of August.

The only sure way to tell hatch year (HY) birds from AHY is to get them in
the hand. That way you can get a close look at the feather structure of
the under tail coverts, the skull ossification and the overall texture of
the greater coverts.

I hope this info helps. Good luck!

Libor

----------
> From: G.Spitler/L.Cannon <gspitler at awinc.com>
> To: 'BirdChat' <BIRDCHAT at LISTSERV.ARIZONA.EDU>
> Cc: 'tweeters' <tweeters at u.washington.edu>
> Subject: Adult vs juvenile Swainson's Thrush
> Date: July 13, 1997 7:16 PM
>
> I am participating in the Forested Landscapes Study and now that it is
mid July it would be great to be able to differentiate adult from juvenile
Swainson's Thrush. Can anyone help ?
> Thanks
> Gail Spitler
> Johnsons Landing, BC
> gspitler at awinc.com