Chris Maack,
Thank you for the information. That helped me alot. Now I know that the
Nothern shrike has a prebasic molt, then becomes an adult.
Thanks!
-Sachiko

On 27 Feb 1997, CHRISTINE W. MAACK wrote:

> 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
>
>