Sachiko,

Thanks for asking about the Northern Shrike, one of my favorite birds. I'm only
aware of two plumages for NOSH, the juvenile, for their first year of life, and
the adult. Juveniles are brownish or brownish-gray (sort of a rusty brown) on
the upper parts and may be brownish on the underside, or heavily barred with
gray. Their face masks are a darker brown and indistinct compared to the
striking black of the adult. Their flight feathers are dark brown rather than
black as in adults. An adult's back and head is pearly gray and underparts
almost white. Males tend to get whiter and brighter overall, with females
remaining a drabber gray, but the difference is not strong enough to allow us to
always be sure which is which.

The prebasic molt is only partial in young birds and takes place from October to
December; it is complete in adult birds and takes place from July to September.
They don't have an alternate (breeding) plumage, only a basic.

I'm getting my details from "Identification Guide to North American Passerines"
by Pyle, Howell, Ynick and DeSante. This is the bird-banders' handbook.

Chris Maack
Anchorage, AK
73201.3124 at compuserve.com